D3FEND™ - A knowledge graph of cybersecurity countermeasures
type: Ontology
version IRI: d3fend.owl
release-date: 2024-12-20T00:42:42.042000+00:00
description: D3FEND is a framework which encodes a countermeasure knowledge base as a knowledge graph. The graph contains the types and relations that define key concepts in the cybersecurity countermeasure domain and the relations necessary to link those concepts to each other. Each of these concepts and relations are linked to references in the cybersecurity literature.
license: MIT
comment: Use of the D3FEND Knowledge Graph, and the associated references from this ontology are subject to the Terms of Use. D3FEND is funded by the National Security Agency (NSA) Cybersecurity Directorate and managed by the National Security Engineering Center (NSEC) which is operated by The MITRE Corporation. D3FEND™ and the D3FEND logo are trademarks of The MITRE Corporation. This software was produced for the U.S. Government under Basic Contract No. W56KGU-18-D0004, and is subject to the Rights in Noncommercial Computer Software and Noncommercial Computer Software Documentation Clause 252.227-7014 (FEB 2012) Copyright 2022 The MITRE Corporation.
version info: 1.0.0

attack-id
type: AnnotationProperty
definition: x attack-id y: The offensive technique x has the att&ck unique id of y.
sub property of: attack-kb-annotation
range: string
domain: Offensive Technique

attack-kb-annotation
type: AnnotationProperty
definition: x attack-kb-annotation y: The offensive technique x has the kb annotation of y.
sub property of: d3fend-annotation
domain: Offensive Technique

cwe-id
type: AnnotationProperty
sub property of: cwe-kb-annotation

cwe-kb-annotation
type: AnnotationProperty
sub property of: d3fend-annotation

d3fend-annotation
type: AnnotationProperty
definition: x d3fend-annotation y: The d3fend object x has the annotation y.
sub property of: versionInfo

d3fend-catalog-annotation-property
type: AnnotationProperty
alternative label: d3fend-vendor-registry-annotation-property
sub property of: d3fend-annotation

d3fend-display-annotation
type: AnnotationProperty
sub property of: d3fend-annotation

d3fend-kb-annotation-property
type: AnnotationProperty
definition: x d3fend-kb-annotation-property y: The entity x had the d3fend kb annotation y.
sub property of: d3fend-annotation

d3fend-kb-reference-annotation
type: AnnotationProperty
definition: x d3fend-kb-data-property y: The reference x has the data property y.
sub property of: d3fend-kb-annotation-property
range: string
domain: Technique Reference

definition
type: AnnotationProperty
definition: x definition y: The d3fend object x has the definition y.
sub property of: d3fend-annotation

description
type: AnnotationProperty
definition: A statement that represents something in words.
sub property of: d3fend-catalog-annotation-property

display-baseurl
type: AnnotationProperty
definition: A base string to use as prefix to create a full URL for an entity. The baseurl must end in a forward slash: /
sub property of: d3fend-display-annotation

display-order
type: AnnotationProperty
definition: x display-order y: An object x should be displayed in ordinal position y when placed or listed in a d3fend display with other objects of its kind.
sub property of: d3fend-display-annotation

display-priority
type: AnnotationProperty
sub property of: d3fend-display-annotation

kb-abstract
type: AnnotationProperty
definition: x kb-abstract y: The reference x has the abstract y.
sub property of: d3fend-kb-reference-annotation
range: string
domain: Technique Reference

kb-article
type: AnnotationProperty
definition: The technique x has the kb-article y, where y is written in Markdown.
sub property of: d3fend-kb-reference-annotation
range: string
domain: Technique

kb-author
type: AnnotationProperty
definition: x kb-author y: The reference x has some author y.
sub property of: d3fend-kb-reference-annotation
range: string
domain: Technique Reference

kb-mitre-analysis
type: AnnotationProperty
definition: x kb-mitre-analysis y: The reference x has the mitre d3fend analysis y.
sub property of: d3fend-kb-annotation-property
range: string
domain: Technique Reference

kb-organization
type: AnnotationProperty
definition: x kb-organization y: The reference x was created or owned by the organization y.
sub property of: d3fend-kb-annotation-property

label
type: AnnotationProperty
sub property of: label

pref-label
type: AnnotationProperty
definition: x pref-label y: The preferred display value for x is y in d3fend tools.
sub property of: d3fend-annotation

release-date
type: AnnotationProperty
definition: x release-date y: The object x has the release-date y.
sub property of: d3fend-annotation
sub property of: versionInfo

synonym
type: AnnotationProperty
definition: an equivalent term.
sub property of: d3fend-annotation

isDefinedBy
type: AnnotationProperty

abuses
type: ObjectProperty
sub property of: uses
definition: x abuses y: The entity x applies an artifact y to a wrong thing or person; x applies y badly or incorrectly.
alternative label: misapplies
alternative label: misuses

access mediated by
type: ObjectProperty
sub property of: associated-with
inverse of: mediates-access-to

accessed-by
type: ObjectProperty
sub property of: associated-with
sub property of: may-be-accessed-by
inverse of: accesses

accesses
type: ObjectProperty
sub property of: associated-with
sub property of: may-access
definition: x accesses y: An subject x takes the action of reading from, writing into, or executing the stored information in the object y. Reads, writes, and executes are specific cases of accesses.

addressed-by
type: ObjectProperty
sub property of: associated-with
inverse of: addresses
definition: x addressed-by y: Relates a resource x (e.g., network host, peripheral device, disk sector, a memory cell or other logical or physical entity) to a discrete address y in an address space that points to it.

addresses
type: ObjectProperty
sub property of: associated-with
definition: x addresses y: Relates a pointer x to a digital artifact y located in the address space to which x points. The address space is part of some digital store, whether it be in memory, an image, or a persistent storage device.
alternative label: points-to

adds
type: ObjectProperty
sub property of: associated-with
sub property of: may-add
definition: x adds y: The subject x adds a data object y, such as a file, to some other digital artifact, such as a directory. Examples include an agent or technique adding a record to a database. or a domain entry to a DNS server.

analyzes
type: ObjectProperty
sub property of: associated-with
sub property of: detects
definition: x analyzes y: The subject x break down object y into components or essential features, assessing y by quantitative methods, qualitative methods, or both. Usually the analysis is done in terms of some model or framework.

associated-with
type: ObjectProperty
sub property of: may-be-associated-with
definition: x associated-with y: The subject x and object y are associated in some way. This is the most general definite relationship in d3fend (i.e., most general relationship that is not prefixed by 'may-'.)

attached-to
type: ObjectProperty
sub property of: associated-with
definition: x attached-to y: A subject x is joined in close association to an object y.

attack-may-be-countered-by
type: ObjectProperty
sub property of: may-be-tactically-associated-with

authenticates
type: ObjectProperty
sub property of: associated-with
sub property of: hardens
definition: x authenticates y: The subject x establishes the authenticity of some y. This relation indicates an authentication event has occurred.

authorizes
type: ObjectProperty
sub property of: associated-with
sub property of: hardens
definition: x authorizes y: A subject x grants authorization or clearance for an agent y to use an object. This relation indicates an authorization event has occurred.

blocks
type: ObjectProperty
sub property of: counters
sub property of: filters
definition: x blocks y: The entity x blocks off the use of digital artifact y by reference to a block or allow list (or both.)

broader
type: ObjectProperty
sub property of: semantic-relation

broader-transitive
type: ObjectProperty
sub property of: semantic-relation

caused-by
type: ObjectProperty
sub property of: associated-with
inverse of: causes
definition: x caused-by y: The event or action x occurs as a consequence of event or action y.

causes
type: ObjectProperty
sub property of: associated-with
definition: x causes y: The event or action x brings about event or action y as a consequence.

communicates-with
type: ObjectProperty
sub property of: associated-with
type: SymmetricProperty
definition: x communicates-with y: x and y exchange signals or data bidirectionally, enabling mutual awareness, coordination, or interaction.

configures
type: ObjectProperty
sub property of: associated-with
sub property of: hardens

connects
type: ObjectProperty
sub property of: associated-with
definition: x connects y: The subject x joins system y by means of communication equipment (to some other system, typically the adversary-targeted host).

contained-by
type: ObjectProperty
sub property of: associated-with
sub property of: may-be-contained-by
inverse of: contains
type: TransitiveProperty

contains
type: ObjectProperty
sub property of: associated-with
sub property of: may-contain
type: TransitiveProperty
definition: x contains y: A core relation that holds between a whole x and its part y. Equivalent to relational concept 'has part' and thus transitive.

controlled-by
type: ObjectProperty
sub property of: associated-with
inverse of: controls
definition: x controlled-by y: x's operation or behavior is directed or regulated by y.

controls
type: ObjectProperty
sub property of: associated-with
definition: x controls y: x directs or regulates y's operational state, behavior, or function.

copies
type: ObjectProperty
sub property of: creates
definition: x copies y: An technique or agent x reproduces or makes and exact copy of some digital artifact y.

copy-of
type: ObjectProperty
sub property of: associated-with
definition: x copy-of y: The subject x is a duplicate of the object y

counters
type: ObjectProperty
sub property of: may-counter

created-by
type: ObjectProperty
sub property of: associated-with
sub property of: may-be-created-by
inverse of: creates

creates
type: ObjectProperty
sub property of: associated-with
sub property of: may-create
definition: x creates y: The subject x bring into existence an object y. Some technique or agent x creates a persistent digital artifact y (as opposed to production of a consumable or transient object.); i.e., bring forth or generate

d3fend-general-object-property
type: ObjectProperty
sub property of: d3fend-object-property

d3fend-kb-object-property
type: ObjectProperty
sub property of: d3fend-object-property
definition: x d3fend-kb-object-property y: The object y is a d3fend knowledge base object property. These properties allow the linkage of knowledge and information supporting and illustrating the d3fend model.

d3fend-object-property
type: ObjectProperty
sub property of: topObjectProperty

d3fend-process-object-property
type: ObjectProperty
sub property of: d3fend-object-property

d3fend-tactical-verb-property
type: ObjectProperty
sub property of: d3fend-object-property

deceives
type: ObjectProperty
sub property of: counters

deceives-with
type: ObjectProperty
sub property of: d3fend-tactical-verb-property

deletes
type: ObjectProperty
sub property of: evicts
sub property of: modifies
definition: x deletes y: A technique or agent x wipes out the digitally or magnetically recorded information of digital object y.

dependent
type: ObjectProperty
sub property of: associated-with
definition: x dependent y: A dependent y is an entity that requires the fulfillment of the requirements specified in dependency x.

depends-on
type: ObjectProperty
sub property of: associated-with
inverse of: has-dependent
definition: x depends-on y: The entity x is contingent on y being available; x relies on y.

detects
type: ObjectProperty
sub property of: counters
sub property of: d3fend-tactical-verb-property

disables
type: ObjectProperty
sub property of: evicts
sub property of: may-disable
sub property of: modifies
definition: x disables y: The technique or agent x makes an entity y unable to perform its actions or capabilities.

drives
type: ObjectProperty
sub property of: associated-with
definition: x drives y: The device driver x causes a system component y to function by controlling it.

employed-by
type: ObjectProperty
sub property of: associated-with
inverse of: employs
definition: x employed-by y: An entity x is put into service by a technique or agent y. Inverse of y employs x.

employs
type: ObjectProperty
sub property of: associated-with

enabled-by
type: ObjectProperty
sub property of: associated-with
inverse of: enables
definition: x enabled-by y: A top level technique y enables a tactic x, that is, the property indicates that a technique y is used to put a particular tactic x into action. In other words, y renders x capable or able for some task. Inverse of enables.

enables
type: ObjectProperty
sub property of: associated-with
definition: x enables y: A top level technique x enables a tactic y, that is, the property indicates that a technique x is used to put a particular tactic y into action. In other words, x renders y capable or able for some task.

encrypts
type: ObjectProperty
sub property of: associated-with
sub property of: hardens
definition: x encrypts y: The entity x converts the ordinary representation of a digital artifact y into a secret code.

end
type: ObjectProperty
sub property of: d3fend-process-object-property

enumerates
type: ObjectProperty
sub property of: reads
definition: x enumerates y: The subject x takes the action of reading from a digital source y to acquire data and create a list of its contents.

erases
type: ObjectProperty
sub property of: associated-with
description: x erases y: A technique x removes recorded data from storage device y creating space for new data.

evaluated-by
type: ObjectProperty
sub property of: associated-with
inverse of: evaluates

evaluates
type: ObjectProperty
sub property of: associated-with
sub property of: may-evaluate

evicts
type: ObjectProperty
sub property of: counters
sub property of: d3fend-tactical-verb-property
sub property of: may-evict

exactly
type: ObjectProperty
sub property of: semantic-relation

executed-by
type: ObjectProperty
sub property of: associated-with
inverse of: executes

executes
type: ObjectProperty
sub property of: accesses
sub property of: may-execute
sub property of: runs
definition: x executes y: The subject x takes the action of carrying out (executing) y, which is a single software module, function, or instruction.

extends
type: ObjectProperty
sub property of: modifies
definition: x extends y: The entity x extend the scope or range or area of entity y, especially in the sense of widen the range of applications.

filters
type: ObjectProperty
sub property of: associated-with
sub property of: isolates
definition: x filters y: An technique or agent x removes some specified set of of entities from the content of a digital artifact y, by passing an artifact's content through a filter. A filter is a device that removes something from whatever passes through it.

forges
type: ObjectProperty
sub property of: creates
definition: x forges y: An technique or agent x counterfeits a digital artifact y, such as a fake credential, with the intent to deceive.

fork
type: ObjectProperty
sub property of: d3fend-process-object-property

hardens
type: ObjectProperty
sub property of: counters
sub property of: d3fend-tactical-verb-property

has-account
type: ObjectProperty
sub property of: owns
definition: x has-account y: The subject x has ownership or possession of some account y.

has-agent
type: ObjectProperty
sub property of: has-participant

has-audience
type: ObjectProperty
sub property of: d3fend-use-case-object-property

has-contribution
type: ObjectProperty
sub property of: d3fend-kb-object-property

has-contributor
type: ObjectProperty
sub property of: d3fend-kb-object-property

has-dependent
type: ObjectProperty
sub property of: associated-with

has-goal
type: ObjectProperty
sub property of: d3fend-use-case-object-property

has-location
type: ObjectProperty
sub property of: associated-with
definition: x has-location y: The entity x is situated in a particular spot or position y.
alternative label: located_in

has-mediator
type: ObjectProperty
sub property of: has-participant

has-member
type: ObjectProperty
sub property of: d3fend-kb-object-property
inverse of: member-of

has-participant
type: ObjectProperty
sub property of: associated-with
inverse of: participates-in
definition: x has-participant y: The event x involves an object y as a participant, indicating that y plays some role in the event, whether actively, passively, or otherwise.

has-prerequisite
type: ObjectProperty
sub property of: d3fend-use-case-object-property

has-procedure
type: ObjectProperty
sub property of: d3fend-general-object-property

has-recipient
type: ObjectProperty
sub property of: associated-with
definition: x has_recipient y: An agent y is the intended recipient and decoder of the information contained in communication x.

has-sender
type: ObjectProperty
sub property of: associated-with
definition: x has_sender y: An agent y is the sender and encoder of the information contained in communication x.

has-weakness
type: ObjectProperty
sub property of: may-have-weakness
inverse of: weakness-of

hides
type: ObjectProperty
sub property of: associated-with
range: Digital Artifact
definition: x hides y: A technique or operation x conceals the digital artifact y.

identified-by
type: ObjectProperty
sub property of: associated-with
inverse of: identifies

identifies
type: ObjectProperty
sub property of: associated-with

impairs
type: ObjectProperty
sub property of: associated-with

implemented-by
type: ObjectProperty
sub property of: associated-with
inverse of: implements

implements
type: ObjectProperty
sub property of: associated-with

initiates
type: ObjectProperty
sub property of: associated-with

injects
type: ObjectProperty
sub property of: executes
definition: x injects y: The subject x takes the action of exploiting a security flaw by introducing (injecting) y, which is code or data that will change the course of execution or state of a computing process to an alternate course or state. Typically code injection is associated with adversaries intending the alternate course to facilitate a malevolent purpose; however, code injection can be unintentional or the intentions behind it may be good or benign.

installs
type: ObjectProperty
sub property of: associated-with
definition: x installs y: An entity x sets up a digital artifact y for subsequent use. For example, an installation program can install application software.

instructed-by
type: ObjectProperty
sub property of: associated-with
definition: x instructed-by y: A subject x takes machine instructions from object y.

instructs
type: ObjectProperty
sub property of: associated-with
definition: x instructs y: A subject x delivers machine instructions to object y.

interprets
type: ObjectProperty
sub property of: executes
sub property of: may-interpret
definition: x interprets y: The subject x interprets the executable script y. The sense of interprets is here 'Parse the source code and perform its behavior directly.'

inventoried-by
type: ObjectProperty
sub property of: associated-with
inverse of: inventories

inventories
type: ObjectProperty
sub property of: associated-with

invoked-by
type: ObjectProperty
sub property of: associated-with
sub property of: may-be-invoked-by
inverse of: invokes

invokes
type: ObjectProperty
sub property of: executes
sub property of: may-invoke
definition: x invokes y: The subject x invokes a system service y by use of an instruction object y that interrupts the program being executed and passes control to the operating system to perform that operation.
alternative label: calls

isolates
type: ObjectProperty
sub property of: associated-with
sub property of: d3fend-tactical-verb-property
definition: x isolates y: The technique or agent x sets digital artifact y apart from other digital artifacts, sequestering y.

kb-reference
type: ObjectProperty
sub property of: d3fend-kb-object-property
inverse of: kb-reference-of
alternative label: has-technique-reference

kb-reference-of
type: ObjectProperty
sub property of: d3fend-kb-object-property
range: Cyber Technique
definition: x kb-is-example-of y: The reference x is an example of technique y.
alternative label: kb-is-example-of

limits
type: ObjectProperty
sub property of: restricts
definition: x limits y: An entity x specifies a designated limit beyond which some entity y cannot function or must be terminated.
alternative label: cutoff

loaded-by
type: ObjectProperty
sub property of: associated-with
inverse of: loads

loads
type: ObjectProperty
sub property of: associated-with
definition: x loads y: The technique or process x transfers a software from a storage y to a computer's memory for subsequent execution.

manages
type: ObjectProperty
sub property of: associated-with
definition: x manages y: The technique or agent x watches and directs the use of a digital artifact y.
alternative label: oversees
alternative label: supervises

mapped-by
type: ObjectProperty
sub property of: associated-with
inverse of: maps

maps
type: ObjectProperty
sub property of: may-map

may-access
type: ObjectProperty
sub property of: may-be-associated-with
inverse of: may-be-accessed-by
definition: x may-access y: They entity x may access the thing y; that is, 'x accesses y' may be true.

may-add
type: ObjectProperty
sub property of: may-be-associated-with
definition: x may-add y: They entity x may add the thing y; that is, 'x adds y' may be true.

may-be-accessed-by
type: ObjectProperty
sub property of: may-be-associated-with

may-be-associated-with
type: ObjectProperty
sub property of: d3fend-object-property
definition: x may-be-associated-with y: The subject x and object y may be associated in some way.

may-be-contained-by
type: ObjectProperty
sub property of: may-be-associated-with
inverse of: may-contain
type: TransitiveProperty

may-be-created-by
type: ObjectProperty
sub property of: may-be-associated-with
inverse of: may-create

may-be-deceived-by
type: ObjectProperty
sub property of: attack-may-be-countered-by
inverse of: may-deceive
pref-label: may be deceived by

may-be-detected-by
type: ObjectProperty
sub property of: attack-may-be-countered-by
inverse of: may-detect
pref-label: may be detected by

may-be-evicted-by
type: ObjectProperty
sub property of: attack-may-be-countered-by
inverse of: may-evict
pref-label: may be evicted by

may-be-hardened-against-by
type: ObjectProperty
sub property of: attack-may-be-countered-by
inverse of: may-harden
pref-label: may be hardened against by

may-be-invoked-by
type: ObjectProperty
sub property of: may-be-associated-with
inverse of: may-invoke

may-be-isolated-by
type: ObjectProperty
sub property of: attack-may-be-countered-by
inverse of: may-isolate
pref-label: may be isolated by

may-be-modified-by
type: ObjectProperty
sub property of: may-be-associated-with
inverse of: may-modify

may-be-tactically-associated-with
type: ObjectProperty
sub property of: may-be-associated-with
definition: x may-be-tactically-associated-with y: the defensive action x may be a tactic that counters offensive action y.

may-be-weakness-of
type: ObjectProperty
sub property of: may-be-associated-with
inverse of: may-have-weakness
domain: Weakness
range: Artifact

may-contain
type: ObjectProperty
sub property of: may-be-associated-with
type: TransitiveProperty
definition: to potentially have as contents or constituent parts; comprise; include.

may-counter
type: ObjectProperty
sub property of: may-be-associated-with

may-counter-attack
type: ObjectProperty
sub property of: may-be-tactically-associated-with

may-create
type: ObjectProperty
sub property of: may-be-associated-with
definition: x may-create y: They entity x may create the entity y; that is, 'x creates y' may be true.

may-deceive
type: ObjectProperty
sub property of: may-counter-attack
pref-label: may deceive

may-detect
type: ObjectProperty
sub property of: may-counter-attack
pref-label: may detect

may-disable
type: ObjectProperty
sub property of: may-evict

may-evaluate
type: ObjectProperty
sub property of: may-be-associated-with

may-evict
type: ObjectProperty
sub property of: may-counter
sub property of: may-counter-attack
pref-label: may evict

may-execute
type: ObjectProperty
sub property of: may-be-associated-with
definition: x may execute y: The subject x might take the action of carrying out (executing) y, which is a single software module, function, or instruction.

may-harden
type: ObjectProperty
sub property of: may-counter-attack
pref-label: may harden

may-have-weakness
type: ObjectProperty
sub property of: may-be-associated-with
domain: Artifact
range: Weakness

may-interpret
type: ObjectProperty
sub property of: may-be-associated-with
definition: x may-interpret y: They entity x may interpret the thing y; that is, 'x interprets y' may be true.

may-invoke
type: ObjectProperty
sub property of: may-be-associated-with
definition: x may-invoke y: They entity x may invoke the thing y; that is, 'x invokes y' may be true.

may-isolate
type: ObjectProperty
sub property of: may-counter-attack
pref-label: may isolate

may-map
type: ObjectProperty
sub property of: may-be-associated-with

may-modify
type: ObjectProperty
sub property of: may-be-associated-with
definition: x may-modify y: They entity x may modify the thing y; that is, 'x modifies y' may be true.

may-produce
type: ObjectProperty
sub property of: may-be-associated-with
definition: x may-produce y: They entity x may produce the thing y; that is, 'x produces y' may be true.

may-query
type: ObjectProperty
sub property of: may-be-associated-with

may-run
type: ObjectProperty
sub property of: may-be-associated-with
definition: x may-run y: They entity x may run the thing y; that is, 'x runs y' may be true.

may-transfer
type: ObjectProperty
sub property of: may-be-associated-with
definition: x may-transfer y: They entity x might send the thing y; that is, 'x transfers y' may be true.

mediates-access-to
type: ObjectProperty
sub property of: associated-with

member-of
type: ObjectProperty
sub property of: d3fend-kb-object-property

modified-by
type: ObjectProperty
sub property of: associated-with
sub property of: may-be-modified-by
inverse of: modifies

modifies
type: ObjectProperty
sub property of: accesses
sub property of: associated-with
sub property of: may-modify
definition: x modifies y: A technique or agent x causes a digital object y to change; become different; or undertake a transformation. Afterwards, the data or state held by a digital object is changed.
alternative label: alters

modifies-part
type: ObjectProperty
sub property of: may-modify
property chain axiom: modifies
property chain axiom: contains
definition: x modifies-part y: The entity x modifies a part of y. [Note: This is a rolification property for the rule 'if one modifies a part of a whole, they modify the whole.' Reasoning for this and similar semantics to come are under evaluation and not part of current d3fend inferences.]

monitors
type: ObjectProperty
sub property of: associated-with
sub property of: detects
definition: x monitors y: The technique or agent x keep tabs on; keeps an eye on; or keep the digital artifact y under surveillance.

narrower
type: ObjectProperty
sub property of: semantic-relation

narrower-transitive
type: ObjectProperty
sub property of: semantic-relation

neutralizes
type: ObjectProperty
sub property of: associated-with
sub property of: hardens
definition: x neutralizes y: The technique x makes the execution of actions of y ineffective by preventing or counterbalancing the effect of y.

next
type: ObjectProperty
sub property of: d3fend-process-object-property

obfuscates
type: ObjectProperty
sub property of: evicts
sub property of: modifies
definition: x obfuscates y: The technique x makes the digital artifact y unclear or obscure. Typically obfuscation is a way to hide a digital artifact from discovery, use, or both.

originates-from
type: ObjectProperty
sub property of: associated-with
definition: x originates-from y: The digital event or artifact x began its network transit from a physical location y.

owns
type: ObjectProperty
sub property of: associated-with
definition: x owns y: The subject x has ownership or possession of some object y.
alternative label: possesses

participates-in
type: ObjectProperty
sub property of: associated-with
definition: x participates-in y: The object x takes part in the event y, signifying that x contributes to or is affected by the event’s occurrence in some way.

powered-by
type: ObjectProperty
sub property of: depends-on
inverse of: powers
definition: x powered-by y: x obtains its essential energy or force from y to perform its function or remain active.

powers
type: ObjectProperty
sub property of: has-dependent
definition: x powers y: x furnishes y with the energy or force required for y's functionality or operation.

preceded-by
type: ObjectProperty
sub property of: associated-with
inverse of: precedes
definition: x preceded-by y: The event or action x occurs after event or action y in time.

precedes
type: ObjectProperty
sub property of: associated-with
definition: x precedes y: The event or action x occurs before event or action y in time.

process-ancestor
type: ObjectProperty
sub property of: process-property
type: TransitiveProperty
definition: x process-ancestor y: The process y is a process ancestor of process x, indicating one or more process creation events were conducted were started at process y and subsequently created process x.

process-image-path
type: ObjectProperty
sub property of: process-property
definition: x process-image-path y: The filepath y is the process image path for the process x, indicating the path to the resource from which the process's image was loaded.
alternative label: processImagePath

process-parent
type: ObjectProperty
sub property of: process-ancestor
definition: x process-parent y: The process y created the process x (directly) with a create process event.
alternative label: processParent

process-property
type: ObjectProperty
sub property of: associated-with
definition: x process-property y: Process x has the a process-property y. This is generalization for specific process object properties.

process-user
type: ObjectProperty
sub property of: process-property
definition: x process-user y: The process x has been executed by the user y.
alternative label: processUser

produced-by
type: ObjectProperty
sub property of: associated-with
inverse of: produces

produces
type: ObjectProperty
sub property of: associated-with
sub property of: may-produce
definition: x produces y: The subject entity x or process produces a data object y, which may be discrete digital object or a stream (e.g., a stream such as network traffic.)
alternative label: outputs

provider
type: ObjectProperty
sub property of: associated-with
definition: x provider y: A provider y is an entity that supplies a service, system, or data resources to a dependent entity x.

queries
type: ObjectProperty
sub property of: associated-with
sub property of: may-query

reads
type: ObjectProperty
sub property of: accesses
definition: x reads y: The subject x takes the action of reading from a digital source y to acquire data and placing it into volatile memory for processing.

recorded-in
type: ObjectProperty
sub property of: associated-with

records
type: ObjectProperty
sub property of: associated-with
definition: x records y: The digital artifact x makes a record of events y; set down in permanent form.

regenerates
type: ObjectProperty
sub property of: associated-with
sub property of: hardens
definition: x regenerates y: The entity x discards the current digital artifact y and creates a new version that serves the same function.

related
type: ObjectProperty
sub property of: semantic-relation
definition: x related y: x has a symmetric associative relation to y.

restores
type: ObjectProperty
sub property of: associated-with

restricted-by
type: ObjectProperty
sub property of: associated-with
inverse of: restricts

restricts
type: ObjectProperty
sub property of: associated-with
definition: x restricts y: An entity x bounds the use of entity y.

resume
type: ObjectProperty
sub property of: d3fend-process-object-property
definition: The agent or technique x continues a previous action on entity y. Usually occurs after suspension on y.

resumes
type: ObjectProperty
sub property of: associated-with
definition: The agent or technique x continues a previous action on entity y. Usually occurs after suspension on y.

runs
type: ObjectProperty
sub property of: associated-with
sub property of: may-run
definition: x runs y: To carry out a process or program y, as on a computer or a machine x; where y may be a large software assembly or a specific module or instruction. Examples: "run a new program on the Mac"; "the computer runs the application software".

semantic-relation
type: ObjectProperty
sub property of: associated-with

signed-by
type: ObjectProperty
sub property of: validated-by
inverse of: signs
definition: x signed-by y: The digital artifact x includes a signature generated by the entity y, certifying the authenticity and integrity of x. This relationship indicates that x has undergone a validation process by y, using cryptographic measures to ensure that x is trustworthy and unaltered since the signing by y.

signs
type: ObjectProperty
sub property of: validates
definition: x signs y: The entity x applies a digital signature to the digital artifact y, thereby asserting its validity, integrity, and authenticity. Typically, this involves cryptographic techniques to securely bind the signature to y, ensuring that y's contents have not been altered and are authentic as endorsed by x.

spoofs
type: ObjectProperty
sub property of: associated-with
sub property of: deceives-with
definition: x spoofs y: The technique x creates a fake instance of a digital artifact y; that is, y is a decoy, fake, or counterfeit.

start
type: ObjectProperty
sub property of: d3fend-process-object-property

strengthens
type: ObjectProperty
sub property of: associated-with
sub property of: hardens
definition: x strengthens y: The technique x make digital artifact y resistant (to harm or misuse.)

summarizes
type: ObjectProperty
sub property of: associated-with
definition: x summarizes y: The sensor x summarizes a set y of events concerning digital artifacts over time

suspends
type: ObjectProperty
sub property of: evicts
definition: x suspends y: The agent or technique x pauses entity y.

terminates
type: ObjectProperty
sub property of: associated-with
sub property of: evicts
definition: x terminates y: The technique x brings to an end or halt to some activity y.
synonym: aborts

unloads
type: ObjectProperty
sub property of: evicts
definition: x unloads y: The technique or artifact performs the action of unloading some artifact (applications, kernel modules, or hardware drivers, etc.) from a computer's memory.

unmounts
type: ObjectProperty
sub property of: associated-with
definition: x unmounts y: An operation x removes the access via computer system's file system the availability of files and directories on a storage artifact y. Unmounts reverse or undo prior mount operations.

updates
type: ObjectProperty
sub property of: hardens
sub property of: modifies
definition: x updates y: The technique x updates the software for component y.

use-limits
type: ObjectProperty
sub property of: limits
definition: x use-limits y: An entity x specifies a designated number of uses beyond which some entity y cannot function or must be terminated.

used-by
type: ObjectProperty
sub property of: associated-with
inverse of: uses
definition: x used-by y: is inverse of y uses x.

uses
type: ObjectProperty
sub property of: associated-with
definition: x uses y: An entity x puts into service a resource or implement y; makes y work or employ for a particular purpose or for its inherent or natural purpose.

validated-by
type: ObjectProperty
sub property of: associated-with
sub property of: hardens
definition: x validated-by y: The digital artifact x has its authenticity and correctness confirmed or verified by the technique, operation, or agent y.

validates
type: ObjectProperty
sub property of: associated-with
sub property of: hardens
definition: x validates y: The technique x proves the digital artifact y is valid; that is, x shows or confirms the validity of y.

verifies
type: ObjectProperty
sub property of: analyzes
sub property of: associated-with
definition: x verifies y: A technique x confirms the truth of a digital artifact y.

weakness-of
type: ObjectProperty
sub property of: may-be-weakness-of

writes
type: ObjectProperty
sub property of: accesses
definition: x writes y: The subject x takes the action of writing to a digital artifact y to store data and placing it into persistent memory for later reference.

archived-at
type: DatatypeProperty
sub property of: d3fend-catalog-data-property
range: anyURI

attack-kb-data-property
type: DatatypeProperty
sub property of: topDataProperty
alternative label: attack-kb-property

date available
type: DatatypeProperty
sub property of: date
range: dateTime
definition: Date that the resource became or will become available.

capec-id
type: DatatypeProperty
sub property of: d3fend-kb-data-property
definition: Unique identifier for a CAPEC technique, i.e. a common attack pattern identified by the pattern CAPEC-[number].

comments
type: DatatypeProperty
sub property of: d3fend-catalog-data-property
type: FunctionalProperty
range: string
definition: x comments y: x claim has provider comments y.

confidence
type: DatatypeProperty
sub property of: d3fend-catalog-data-property

control-name
type: DatatypeProperty
sub property of: d3fend-external-control-data-property
definition: The control (or control enhancement) name.

date created
type: DatatypeProperty
sub property of: date
range: dateTime
definition: Date of creation of the resource.

d3fend-artifact-data-property
type: DatatypeProperty
sub property of: d3fend-data-property
domain: Digital Artifact
definition: x d3fend-artifact-data-property y: The artifact x has the data property y.

d3fend-catalog-data-property
type: DatatypeProperty
sub property of: d3fend-data-property
sub property of: d3fend-external-control-data-property
alternative label: d3fend-vendor-registry-data-property

d3fend-comment
type: DatatypeProperty
sub property of: d3fend-kb-data-property
definition: x d3fend-comment y: The entity x has an D3FEND team written a public note about entity y.

d3fend-data-property
type: DatatypeProperty
sub property of: topDataProperty

d3fend-display-property
type: DatatypeProperty
sub property of: d3fend-data-property
definition: x d3fend-display-property y: An object x should be displayed using the display property y, when it applies.

d3fend-external-control-data-property
type: DatatypeProperty
sub property of: d3fend-data-property

d3fend-id
type: DatatypeProperty
sub property of: d3fend-kb-data-property
definition: Unique identifier for a D3FEND technique. D3-[Acronym].

d3fend-kb-data-property
type: DatatypeProperty
sub property of: d3fend-data-property
definition: x d3fend-kb-data-property y: The d3fend knowledge base object x has a data property y; e.g., a string capturing a particular aspect or section of a knowledge base article.

date
type: DatatypeProperty
sub property of: d3fend-data-property
range: dateTime
definition: A point or period of time associated with an event in the lifecycle of the resource.

expectation-rating
type: DatatypeProperty
sub property of: d3fend-catalog-data-property

has-link
type: DatatypeProperty
sub property of: d3fend-kb-data-property
range: anyURI
definition: x has-link y: The d3fend analysis x has the link y.

identifier
type: DatatypeProperty
sub property of: d3fend-catalog-data-property
range: string

date issued
type: DatatypeProperty
sub property of: date
range: dateTime
definition: Date of formal issuance of the resource.

kb-reference-title
type: DatatypeProperty
sub property of: d3fend-kb-data-property
range: string
definition: x kb-reference-title y: The d3fend knowledge base reference x has the reference title string y.

date modified
type: DatatypeProperty
sub property of: date
range: dateTime
definition: Date on which the resource was changed.

name
type: DatatypeProperty
sub property of: d3fend-catalog-data-property

operating-system
type: DatatypeProperty
sub property of: d3fend-catalog-data-property
range: string
definition: x operating-system y: The product x is supported on operating system y.

process-command-line-arguments
type: DatatypeProperty
sub property of: process-data-property
definition: x process-command-line-arguments y: The process x has the process command line arguments data y.

process-data-property
type: DatatypeProperty
sub property of: d3fend-artifact-data-property
definition: x process-data-property y: The process x has the data property y.

process-environmental-variables
type: DatatypeProperty
sub property of: process-data-property
definition: x process-environment-variables y: The process x has the process environmental variables data y.
alternative label: process-environmental-variable

process-identifier
type: DatatypeProperty
sub property of: process-data-property
definition: x process-identifier y: The process x has the process identifier y.

process-security-context
type: DatatypeProperty
sub property of: process-data-property
domain: Process
definition: x process-security-context y: The process x has the process security context data y.

date published
type: DatatypeProperty
sub property of: date
range: dateTime
definition: Date of publication of the resource.

rating
type: DatatypeProperty
sub property of: d3fend-catalog-data-property
type: FunctionalProperty

stage
type: DatatypeProperty
sub property of: d3fend-catalog-data-property
type: FunctionalProperty

text
type: DatatypeProperty
sub property of: d3fend-catalog-data-property
definition: The text of the document (i.e., terms of license.)

title
type: DatatypeProperty
sub property of: d3fend-catalog-data-property
range: string
definition: A name given to the resource.

date valid
type: DatatypeProperty
sub property of: date
range: dateTime
definition: Date (often a range) of validity of a resource.

version
type: DatatypeProperty
sub property of: d3fend-catalog-data-property
sub property of: d3fend-external-control-data-property
type: FunctionalProperty
range: Datatype
  union of: integer
  union of: string
definition: x version y: The product or service x has the version y.

windows-registry-data-property
type: DatatypeProperty
sub property of: d3fend-artifact-data-property
definition: x windows-registry-data-property y: The windows registry entry x has the property y.

windows-registry-key
type: DatatypeProperty
sub property of: windows-registry-data-property
definition: x value y: The key-value pair x has the key y.
alternative label: key

windows-registry-value
type: DatatypeProperty
sub property of: windows-registry-data-property
definition: x value y: The key-value pair x has the data value y.
alternative label: value

ANN-based Clustering
type: Class
subclass of: Cluster Analysis
type: NamedIndividual
d3fend-id: D3A-ABC
definition: Combines the principles of Artificial Neural Networks (ANN) and clustering methods.
kb-article: ## References Wikipedia. (n.d.). Artificial neural network. [Link](https://en.wikipedia.org/wiki/Artificial_neural_network)

ARIMA Model
type: Class
subclass of: Time Series Analysis
type: NamedIndividual
d3fend-id: D3A-AM
definition: An autoregressive integrated moving average (ARIMA) model is a generalization of an autoregressive moving average (ARMA) model.
kb-article: ## References Wikipedia. (n.d.). Autoregressive integrated moving average. [Link](https://en.wikipedia.org/wiki/Autoregressive_integrated_moving_average)
synonym: Autoregressive Integrated Moving Average Model

ARMA Model
type: Class
subclass of: Time Series Analysis
type: NamedIndividual
type: Time Series Analysis
d3fend-id: D3-ARMA
definition: Autoregressive-moving-average (ARMA) models provide a parsimonious description of a (weakly) stationary stochastic process in terms of two polynomials, one for the autoregression (AR) and the second for the moving average (MA).
kb-article: ## References Wikipedia. (n.d.). Autoregressive-moving-average model. [Link](https://en.wikipedia.org/wiki/Autoregressive%E2%80%93moving-average_model)
synonym: Autoregressive moving average model

ATTACK Enterprise Data Source
type: Class
subclass of: ATTACK Enterprise Thing

ATTACK Enterprise Mitigation
type: Class
subclass of: ATTACK Enterprise Thing
subclass of: Restriction
  on property: semantic-relation
  some values from: Defensive Technique
subclass of: Restriction
  on property: d3fend-comment
  some values from: string

ATTACK Enterprise Tactic
type: Class
subclass of: ATTACK Enterprise Thing

ATTACK Enterprise Technique
type: Class
subclass of: ATTACK Enterprise Thing

ATTACK Enterprise Thing
type: Class
subclass of: ATTACK Thing

ATTACK Merged Thing
type: Class
subclass of: ATTACK Thing

ATTACK Thing
type: Class
subclass of: External Threat Model Thing
definition: ATTACK things are concepts defined in the ATT&CK Framework.

Academic Paper Reference
type: Class
subclass of: Technique Reference
pref-label: Academic Paper

Access
type: Class
subclass of: Event
subclass of: Restriction
  on property: accesses
  some values from: Resource
subclass of: Restriction
  on property: has-mediator
  some values from: Access Mediator

Access Control Administration Event
type: Class
subclass of: Access Control Event
definition: An event concerning the administrative actions of setting, modifying, or abolishing permissions, configuring access control settings, and managing user access rights to ensure alignment with access control policies.
alternative label: Permission Administration Event
alternative label: Permission Provisioning Event

Access Control Configuration
type: Class
subclass of: Configuration Resource
type: NamedIndividual
definition: Information about what access permissions are granted to particular users for particular objects

Access Control Event
type: Class
subclass of: Authorization Event
subclass of: Restriction
  on property: has-participant
  some values from: Access Control Configuration
definition: An event that captures the implementation or evaluation of access control measures, including the application of rules and policies to govern the accessibility of resources by agents within a digital system.

Access Control Group
type: Class
subclass of: Access Control Configuration
subclass of: Restriction
  on property: restricted-by
  some values from: Access Control List
type: NamedIndividual
restricted-by: Access Control List
definition: A collection of objects that can have access controls placed on them.

Access Control List
type: Class
subclass of: Access Control Configuration
subclass of: Restriction
  on property: restricts
  some values from: User Group
type: NamedIndividual
restricts: User Group
definition: A list of permissions attached to an object.

Access Denied Event
type: Class
subclass of: Access Mediation Event
definition: An event indicating the refusal of access to a resource, where an access request has been evaluated and denied based on current authorization policies, preventing operations by the requesting agent.

Access Granted Event
type: Class
subclass of: Access Mediation Event
definition: An event signifying that access to a resource has been authorized and successfully enforced, allowing the requesting agent to perform specified operations based on the access control policies.

Access Mediation
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Isolate
type: NamedIndividual
enables: Isolate
kb-reference: Reference-CNNSI-4009
d3fend-id: D3-AMED
definition: Access mediation is the process of granting or denying specific requests to: 1) obtain and use information and related information processing services; and 2) enter specific physical facilities (e.g., Federal buildings, military establishments, border crossing entrances).
synonym: Access Control

Access Mediation Event
type: Class
subclass of: Access Control Event
subclass of: Restriction
  on property: has-participant
  some values from: Access Mediator
definition: An event involving the intermediary control mechanism that evaluates access requests and enforces access control decisions, ensuring that subjects' resource interactions comply with the established access policies.
alternative label: Access Enforcement Event

Access Mediator
type: Class
subclass of: D3FEND Core
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: implements
  some values from: Access Control Configuration
subclass of: Restriction
  on property: mediates-access-to
  some values from: Resource
subclass of: Restriction
  on property: used-by
  some values from: Agent
type: NamedIndividual
implements: Access Control Configuration
mediates-access-to: Resource
used-by: Agent

Access Modeling
type: Class
subclass of: Operational Activity Mapping
subclass of: Restriction
  on property: maps
  some values from: Access Control Configuration
subclass of: Restriction
  on property: maps
  some values from: User Account
type: NamedIndividual
maps: Access Control Configuration
maps: User Account
d3fend-id: D3-AM
definition: Access modeling identifies and records the access permissions granted to administrators, users, groups, and systems.

Access Policy Administration
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Isolate
type: NamedIndividual
enables: Isolate
d3fend-id: D3-APA
definition: Access policy administration is the systematic process of defining, implementing, and managing access control policies that dictate user permissions to resources.
synonym: Access Control Administration

Access Process
type: Class
subclass of: System Call
subclass of: Restriction
  on property: accesses
  some values from: Process
type: NamedIndividual
accesses: Process

Access Token
type: Class
subclass of: Credential
type: NamedIndividual
definition: In computer systems, an access token contains the security credentials for a login session and identifies the user, the user's groups, the user's privileges, and, in some cases, a particular application. Typically one may be asked to enter the access token (e.g. 40 random characters) rather than the usual password (it therefore should be kept secret just like a password).
alternative label: Ticket
alternative label: Token

Account Locking
type: Class
subclass of: Credential Eviction
subclass of: Restriction
  on property: disables
  some values from: User Account
type: NamedIndividual
disables: User Account
kb-reference: Reference-AccountMonitoring ForescoutTechnologies
kb-reference: Reference-FrameworkForNotifyingADirectoryServiceOfAuthenticationEventsProcessedOutsideTheDirectoryService OracleInternationalCorp
date created: 2020-08-05T00:00:00
d3fend-id: D3-AL
definition: The process of temporarily disabling user accounts on a system or domain.
kb-article: ## How it works Management servers with enterprise policies for account management provide the ability to enable and disable account for given rules. The rules may include specific periods of time (eg. weekend, plant shutdown, leave periods), specific user types or groups, or individual users. ## Considerations * Local accounts caches vs centralized account management * Single Sign-on * Role based vs Attribute based systems ## Examples of account configuration stores * Directory Services * Active Directory * RADIUS * LDAP * Oracle User Account Management * JumpCloud

Action
type: Class
subclass of: Event
subclass of: Restriction
  on property: has-agent
  some values from: Agent
type: NamedIndividual

Active Certificate Analysis
type: Class
subclass of: Certificate Analysis
type: NamedIndividual
kb-reference: Reference-SecuringWebTransactions
date created: 2020-08-05T00:00:00
d3fend-id: D3-ACA
definition: Actively collecting PKI certificates by connecting to the server and downloading its server certificates for analysis.
kb-article: ## How it works Analysis of server certificates using active methods to detect if certificates have been misconfigured or spoofed by using elements of the certificate, certificate authorities and signatures. ### Certificate validity analysis This can be accomplished by verifying the digital signature on certificate. ### Certificate path analysis The client's browser can perform path verification to ensure that the server's certificate contains a valid trust anchor. ### Certificate configuration analysis Some browsers can be configured to implement the key-usage extensions contained certificates. This can help to prevent a certificate from being misused. ### Certificate revocation status analysis Using either Certificate Revocation Lists (CRLs) or Online Certificate Status Protocol (OCSP) to determine the revocation status. OCSP Stapling, binding the status with the certificate, helps to mitigate potential delay in status verifications. ## Considerations * Management of the PKI across the enterprise typically requires automation to maintain scalability and flexibility * If the certificate authority, issuing the certificate, is compromised then all of the certificates issued by the CA are suspect * There may be delays associated with updates to certificates * Revoked certificates give the appearance of valid certificates until they are published to a trusted revocation service (OCSP or CRL) * The revocation service (OCSP or CRL) may be down during our connection and a browser will need to make a decision will need to be made about trusting the connection

Active Learning
type: Class
subclass of: Machine Learning
type: NamedIndividual
d3fend-id: D3A-AL
definition: Active learning aims to improve learning efficiency by allowing the learning algorithm to select which data to learn from.
kb-article: ## How it works Traditional supervised learning often requires a large number of labeled instances, which can be costly or time-consuming to obtain. Active learning addresses this labeling bottleneck by asking an oracle (e.g., a human annotator) to label selected unlabeled instances. The goal is to achieve high accuracy with minimal labeling effort. ## Considerations Active learning is particularly useful in scenarios where data is abundant but labeled instances are scarce or expensive. Examples include speech recognition, information extraction, and document classification. ## References - Wikipedia article on Active Learning (machine learning) [Link](https://en.wikipedia.org/wiki/Active_learning_(machine_learning)) - Settles, B. (2009). Active Learning Literature Survey. [Link](https://burrsettles.com/pub/settles.activelearning.pdf)

Active Logical Link Mapping
type: Class
subclass of: Logical Link Mapping
subclass of: Restriction
  on property: may-query
  some values from: Network Agent
type: NamedIndividual
kb-reference: Reference-IdentificationOfTracerouteNodesAndAssociatedDevices
kb-reference: Reference-SNMPNetworkAutoDiscovery
may-query: Network Agent
d3fend-id: D3-ALLM
definition: Active logical link mapping sends and receives network traffic as a means to map the whole data link layer, where the links represent logical data flows rather than physical connection
kb-article: ## How it works Active logical link mapping establishes awareness of logical links in the network by sending data over the network to gather information about logical connections in the network. Typically this will be achieved through network telemetry coordinated for network management and monitoring and will use a link layer discovery protocol such as LLDP and the information gathered and aggregated a higher levels using an application protocol such as SNMP. The information may be polled by network management softare or configured once and then pushed from network sensors (or agents.) Another means of establishing network connectivity is by means of sendingn traffic through the use of a tool such as traceroute, to determine the logical paths through the network architecture. ## Considerations * Best practice is to encrypte network monitoring data and require authentication for queries or admin/management functions. * Push notifications reduce bandwidth necessary to capture and maintain information if reliable transport is used. * Special consideration should be made before using of active scanning in OT networks and OT-safe options chosen where available.

Active Physical Link Mapping
type: Class
subclass of: Physical Link Mapping
subclass of: Restriction
  on property: may-query
  some values from: Network Agent
disjoint with: Direct Physical Link Mapping
type: NamedIndividual
kb-reference: Reference-IdentificationOfTracerouteNodesAndAssociatedDevices
may-query: Network Agent
d3fend-id: D3-APLM
definition: Active physical link mapping sends and receives network traffic as a means to map the physical layer.
synonym: Active Physical Layer Mapping

Activity Dependency
type: Class
subclass of: Dependency
definition: An activity dependency is a dependency that indicates an activity has an activity or agent which relies on it in order to be functional.

Actor-Critic
type: Class
subclass of: Policy Gradient
subclass of: Temporal Difference Learning
type: NamedIndividual
d3fend-id: D3A-AC
definition: Actor-Critic is a Temporal Difference(TD) version of Policy gradient. It has two networks: Actor and Critic. The actor decided which action should be taken and critic inform the actor how good was the action and how it should adjust. The learning of the actor is based on policy gradient approach. In comparison, critics evaluate the action produced by the actor by computing the value function.
kb-article: ## References The Actor-Critic Reinforcement Learning Algorithm. Medium. [Link](https://medium.com/intro-to-artificial-intelligence/the-actor-critic-reinforcement-learning-algorithm-c8095a655c14).

Actuator
type: Class
subclass of: Output Device
definition: An actuator is a mechanical or electromechanical device that, upon receiving a relatively low-energy control signal (e.g., electrical voltage, fluid pressure, or human force), translates its primary energy source (electric, hydraulic, or pneumatic) into targeted mechanical motion or adjustment. It typically works in conjunction with a control device (like a valve or logic driver) and is central to automation, enabling machines or systems to move, open, close, or otherwise manipulate their components or environment. By amplifying or redirecting energy from one form to another, the actuator executes control commands, thereby automating processes in industrial, automotive, aerospace, and other domains where precise mechanical action is essential.

Adaptive Resonance Theory Clustering
type: Class
subclass of: ANN-based Clustering
type: NamedIndividual
d3fend-id: D3A-ARTC
definition: Adaptive Resonance Theory (ART) Clustering is a neural network algorithm used for clustering data and is open to new learning(i.e. adaptive) without discarding the previous or the old information(i.e. resonance).
kb-article: ## References GeeksforGeeks. (n.d.). Adaptive Resonance Theory (ART). [Link](https://www.geeksforgeeks.org/adaptive-resonance-theory-art/)

Add User to Group Event
type: Class
subclass of: Group Management Event
definition: An event where a user is added to a group, granting the user the permissions and privileges associated with the group.

Address Space
type: Class
subclass of: Digital Information Bearer
definition: An address space defines a range of discrete addresses, each of which may correspond to a network host, peripheral device, disk sector, a memory cell or other logical or physical entity. For software programs to save and retrieve stored data, each unit of data must have an address where it can be located. The number of address spaces available depends on the underlying address structure, which is usually limited by the computer architecture being used.

Administrative Network Activity Analysis
type: Class
subclass of: Network Traffic Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Intranet Administrative Network Traffic
type: NamedIndividual
analyzes: Intranet Administrative Network Traffic
kb-reference: Reference-MethodAndSystemForDetectingSuspiciousAdministrativeActivity VectraNetworksInc
kb-reference: Reference-RemoteRegistry MITRE
kb-reference: Reference-WindowsRemoteManagement WinRM MITRE
date created: 2020-08-05T00:00:00
d3fend-id: D3-ANAA
definition: Detection of unauthorized use of administrative network protocols by analyzing network activity against a baseline.
kb-article: ## How it works Network protocols such as RDP, IPMI, SSH, SNMP, VNC, MOSH, NX, TeamViewer, SPICE, PCoIP, and others are used by system administrators to remotely manage servers. Defenders monitor administrative network activity to determine if the use of remote protocols is malicious. Attackers can abuse administrative protocols and leverage them for initial access to various endpoints. For example, an attacker with valid credentials will remotely SSH or RDP into a server and attempt to blend in with existing traffic from system administrators. By monitoring the traffic activity, it is possible to detect when the protocols are behaving differently from a known baseline of system administration activity. ## Considerations * Administrative traffic can be encrypted, making network protocol analysis a challenge * False alarms can be mitigated by integration with inventory management systems

Administrative Network Traffic
type: Class
subclass of: Network Traffic
type: NamedIndividual
definition: Administrative network traffic is network traffic related to the remote administration or control of hosts or devices through a standard remote administrative protocol. Remote shells, terminals, RDP, and VNC are examples of these protocols, which are typically only used by administrators.

Agent
type: Class
subclass of: D3FEND Core
type: NamedIndividual
definition: An entity capable of performing intentional actions.

Agent Authentication
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: authenticates
  some values from: Agent
subclass of: Restriction
  on property: enables
  some values from: Harden
subclass of: Restriction
  on property: strengthens
  some values from: User Account
type: NamedIndividual
authenticates: Agent
enables: Harden
kb-reference: Reference-NIST-Special-Publication-800-53-Revision-5
strengthens: User Account
d3fend-id: D3-AA
definition: Agent authentication is the process of verifying the identities of agents to ensure they are authorized and trustworthy participants within a system.

Agent Group
type: Class
subclass of: Group
subclass of: Restriction
  on property: contains
  some values from: Agent

Agglomerative Clustering
type: Class
subclass of: Hierarchical Clustering
type: NamedIndividual
d3fend-id: D3A-AC
definition: Agglomerative Clustering is a type of hierarchical clustering method where data points are grouped together based on similarity. Initially, each data point is treated as an individual cluster, and then in successive iterations, the closest clusters are merged until only one large cluster remains or until a specified stopping criterion is met.
kb-article: ## How it works Agglomerative clustering starts with each data point as its own cluster. The algorithm then iterates, identifying the two clusters that are closest to each other based on a defined distance metric (e.g., Euclidean, Manhattan). These two clusters are then merged into a single cluster. This process continues iteratively, merging the closest pairs of clusters in each step until all data points are merged into a single cluster or until other stopping criteria are achieved. A dendrogram, which is a tree-like diagram, can be used to represent the sequence of merges, providing a visual representation of the hierarchical structure of data. ## Considerations - **Choice of Distance Metric**: The outcome can vary significantly depending on the chosen distance metric (e.g., Euclidean, Manhattan). - **Scalability**: Agglomerative clustering can be computationally intensive for large datasets. - **Sensitivity**: The method can be sensitive to outliers, which might affect the quality of the clusters formed. ## Key Test Considerations - **Unsupervised Learning**: - **Number of Clusters**: Determine an optimal number of clusters using the dendrogram and techniques like the elbow method. - **Cluster Analysis**: - **Silhouette Score**: Evaluates how similar an object is to its own cluster compared to other clusters. A higher silhouette score indicates that the object is well matched to its own cluster and poorly matched to neighboring clusters. - **Dunn Index**: Measures the ratio between the smallest distance between observations not in the same cluster to the largest intra-cluster distance. - **Hierarchical Clustering**: - **Cophenetic Correlation Coefficient**: Measures the correlation between the distances of points in feature space and their distances on the dendrogram. Helps assess the fidelity of the dendrogram in preserving pairwise distances between samples. - **Agglomerative Clustering**: - **Linkage Criteria**: Test different linkage criteria (e.g., single, …

Alethic Logic
type: Class
subclass of: Modal Logic
type: NamedIndividual
d3fend-id: D3A-AL
definition: Alethic logic is a modal logic that addresses the modalities of necessity and possibility.
kb-article: ## References 1. Alethic logic. (2023, June 4). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Modal_logic#Alethic_logic)

Alias
type: Class
subclass of: Slow Symbolic Link
definition: In macOS, an alias is a small file that represents another object in a local, remote, or removable[1] file system and provides a dynamic link to it; the target object may be moved or renamed, and the alias will still link to it (unless the original file is recreated; such an alias is ambiguous and how it is resolved depends on the version of macOS).

Allocate Memory
type: Class
subclass of: System Call
subclass of: Restriction
  on property: creates
  some values from: Memory Block
type: NamedIndividual
creates: Memory Block

Analytic Technique
type: Class
subclass of: Technique
definition: A process in which a computer examines information using mathematical methods in order to find useful patterns.

Analytical Purpose
type: Class
subclass of: Goal

Anonymous Pipe
type: Class
subclass of: Pipe
definition: In computer science, an anonymous pipe is a simplex FIFO communication channel that may be used for one-way interprocess communication (IPC). An implementation is often integrated into the operating system's file IO subsystem. Typically a parent program opens anonymous pipes, and creates a new process that inherits the other ends of the pipes, or creates several new processes and arranges them in a pipeline.

Answer Set Programming
type: Class
subclass of: Logic Programming
type: NamedIndividual
d3fend-id: D3A-ASP
definition: Answer set programming is a form of declarative programming based on the stable model (answer set) semantics of logic programming.
kb-article: ## How it works Answer set programming (ASP) is oriented towards difficult (primarily NP-hard) search problems. The computational process employed in the design of many answer set solvers is an enhancement of the DPLL algorithm and, in principle, it always terminates (unlike Prolog query evaluation, which may lead to an infinite loop). In a more general sense, ASP includes all applications of answer sets to knowledge representation and the use of Prolog-style query evaluation for solving problems arising in these applications. ## References 1. Answer set programming. (2023, April 27). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Answer_set_programming)
synonym: ASP

Application
type: Class
subclass of: Software
subclass of: Restriction
  on property: may-contain
  some values from: Application Configuration
type: NamedIndividual
may-contain: Application Configuration
definition: A program that gives a computer instructions that provide the user with tools to accomplish a task; "he has tried several different word processing applications". Distinct from system software that is intrinsically part of the operating system. An application can be made up of executable files, configuration files, shared libraries, etc.

Application-based Process Isolation
type: Class
subclass of: Execution Isolation
subclass of: Restriction
  on property: isolates
  some values from: Process
subclass of: Restriction
  on property: restricts
  some values from: Subroutine
type: NamedIndividual
isolates: Process
kb-reference: Reference-PrivateApplicationAccessWithBrowserIsolation
kb-reference: Reference-ProtectingWebApplicationsFromUntrustedEndpointsUsingRemoteBrowserIsolation
kb-reference: Reference-SiteIsolationDesignDocument
restricts: Subroutine
d3fend-id: D3-ABPI
definition: Application code which prevents its own subroutines from accessing intra-process / internal memory space.
kb-article: ## How it works Some applications implement logic to permit or deny a particular subroutine access to other data within the same applicaition process. This is intended to prevent critical application process data from being tampered with. ### Application-based Process Isolation in web browsers. Isolation in browsers usually is designed with the following architectural mindset: * Sandboxes and web resources should not be allowed to access each other because compromise of one should not effect the other. * The principle of least-privilege should be followed when browsing. The following aspects help make browser-based process isolation possible: * Same Origin Policy * Separate tabs and iframes use their own DOMs (cross-site document object models always run as a different process) * CORS ensures cross-site data is not delivered to a process unless the server allows it * Cookie and local data storage is separated by domain/site * Separate execution environments (threads) ## Considerations - Using isolation in browsers does mitigate and protect by default some types of attacks (e.g. renderer attacks and access to the filesystem) but it depends on correct configuration of CORS, use of valid/appropriate certificates. - Application-based Process Isolation may increase memory footprint. - Application-based Process Isolation may decrease application performance.
synonym: Browser-based Process Isolation
synonym: Remote Browser Isolation
synonym: Sandbox

Application Configuration
type: Class
subclass of: Configuration Resource
type: NamedIndividual
definition: Information used to configure the parameters and initial settings for an application.

Application Configuration Database
type: Class
subclass of: Configuration Database
subclass of: Restriction
  on property: contains
  some values from: Application Configuration Database Record
type: NamedIndividual
contains: Application Configuration Database Record
definition: A database used to hold application configuration data.

Application Configuration Database Record
type: Class
subclass of: Application Configuration
subclass of: Configuration Database Record
type: NamedIndividual
definition: A database record holding information used to configure the parameters and initial settings for an application.

Application Configuration File
type: Class
subclass of: Configuration File
subclass of: Restriction
  on property: contains
  some values from: Application Configuration
type: NamedIndividual
contains: Application Configuration
definition: A file containing Information used to configure the parameters and initial settings for an application.. A plist file is an example of this type of file for macOS. Usually text-based.

Application Configuration Hardening
type: Class
subclass of: Application Hardening
subclass of: Restriction
  on property: hardens
  some values from: Application Configuration
type: NamedIndividual
hardens: Application Configuration
kb-reference: Reference-Windows10STIG
d3fend-id: D3-ACH
definition: Modifying an application's configuration to reduce its attack surface.
kb-article: ## How it works Application configuration settings can be configured to limit the permissions on an application or disable certain vulnerable application features. Hardening an application's configuration involves analyzing not only the application but also the environment in which the application is run in for potential vulnerabilities.

Application Deletion Event
type: Class
subclass of: Application Event
definition: An event capturing the removal of an application from a system, ensuring its binaries, configuration files, and registry entries are deleted or deactivated.

Application Disable Event
type: Class
subclass of: Application Event
definition: An event capturing the disabling of an application, preventing it from being operational or accessed until re-enabled.

Application Enable Event
type: Class
subclass of: Application Event
definition: An event representing the enabling of an application, allowing it to be started or accessed when required.

Application Event
type: Class
subclass of: Digital Event
subclass of: Restriction
  on property: has-participant
  some values from: Application
definition: An event that captures the behavior, state, or interactions of software applications or services operating within a system. Application events encompass lifecycle changes, configuration updates, and operational anomalies, providing insight into the health and performance of software components.

Application Hardening
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Harden
type: NamedIndividual
enables: Harden
d3fend-id: D3-AH
definition: Application Hardening makes an executable application more resilient to a class of exploits which either introduce new code or execute unwanted existing code. These techniques may be applied at compile-time or on an application binary.
kb-article: ## Technique Overview Exploits may, for example, rely on knowledge of addresses in a process's memory, they may alter memory contents, and they may cause a program to use instructions in a way that they were not intended. By, for example, including code that dynamically changes the memory address of data or code on each run, introducing logic to validating the memory contents before certain potentially dangerous flows are executed, or monitoring a program for unusual sequence of instructions, this makes it harder for an attacker to craft a working exploit.
synonym: Process Hardening

Application Installation Event
type: Class
subclass of: Application Event
definition: An event representing the installation of an application onto a system, making it available for use and interaction.

Application Installer
type: Class
subclass of: User Application
type: NamedIndividual

Application Inventory Sensor
type: Class
subclass of: Endpoint Sensor
subclass of: Restriction
  on property: monitors
  some values from: Application
type: NamedIndividual
monitors: Application
definition: Collects information on applications on an endpoint.

Application Layer Event
type: Class
subclass of: Network Event
definition: An event occurring at the application layer, involving protocols that support application-specific communication.

Application Layer Firewall
type: Class
subclass of: Firewall
definition: An application firewall is a form of firewall that controls input, output, and/or access from, to, or by an application or service. It operates by monitoring and potentially blocking the input, output, or system service calls that do not meet the configured policy of the firewall. The application firewall is typically built to control all network traffic on any OSI layer up to the application layer. It is able to control applications or services specifically, unlike a stateful network firewall, which is - without additional software - unable to control network traffic regarding a specific application. There are two primary categories of application firewalls, network-based application firewalls and host-based application firewalls.
alternative label: Application Firewall

Application Layer Link
type: Class
subclass of: Logical Link

Application Process
type: Class
subclass of: User Process
subclass of: Restriction
  on property: runs
  some values from: Application
type: NamedIndividual
runs: Application
definition: An application process is an instance of an application computer program that is being executed.

Application Process Configuration
type: Class
subclass of: Application Configuration
definition: The current configuration of an application process, stored in memory. It may have been sourced from other types of application configurations, e.g. Application Configuration Files or Application Configuration Database Records.

Application Restart Event
type: Class
subclass of: Application Event
definition: An event where an application is sequentially stopped and started, typically to refresh its state, apply updates, or resolve issues while preserving its availability.

Application Rule
type: Class
subclass of: Application Configuration
definition: A configuration of an application which is used to apply logical or data processing functions to data processed by the application.

Application Shim
type: Class
subclass of: Shim
definition: An application shim adapts an application program to run on a version of a platform for which they were not originally created. Most commonly "Application Shimming" refers to use of The Windows Application Compatibility Toolkit (ACT) provides backward compatibility by simulating the behavior of older version of Windows.

Application Start Event
type: Class
subclass of: Application Event
definition: An event where an application transitions from an inactive state to an active state, initializing its resources and becoming operational for user interaction or automated processes.

Application Stop Event
type: Class
subclass of: Application Event
definition: An event capturing the cessation of an application’s operations, transitioning it to an inactive state and releasing any allocated resources.

Application Update Event
type: Class
subclass of: Application Event
definition: An event describing changes made to an application, such as updates, reconfigurations, or patch installations, while maintaining its presence on the system.

Approximate String Matching
type: Class
subclass of: Partial Matching
type: NamedIndividual
d3fend-id: D3A-ASM
definition: Approximate string matching is a form of string matching that allows errrors.
kb-article: ## References 1. Navarro, G. (2001). A guided tour to approximate string matching. _ACM Computing Surveys_, 33(1), 31-88. [Link](https://doi.org/10.1145/375360.375365)

Archive File
type: Class
subclass of: File
type: NamedIndividual
definition: An archive file is a file that is composed of one or more computer files along with metadata. Archive files are used to collect multiple data files together into a single file for easier portability and storage, or simply to compress files to use less storage space. Archive files often store directory structures, error detection and correction information, arbitrary comments, and sometimes use built-in encryption.

Artifact
type: Class
subclass of: D3FEND Core
type: NamedIndividual
definition: A man-made object taken as a whole.

Artifact Server
type: Class
subclass of: Web Server
definition: A digital artifact server provides access services to digital artifacts in a repository. It provides an associated set of data management, search and access methods allowing application-independent access to the content.

Artificial Neural Network Classification
type: Class
subclass of: Classification
type: NamedIndividual
d3fend-id: D3A-ANNC
d3fend-annotation: Classification ANNs seek to classify an observation as belonging to some discrete class as a function of the inputs. The input features (independent variables) can be categorical or numeric types, however, we require a categorical feature as the dependent variable.
kb-article: ## References ANN Classification. [Link](http://uc-r.github.io/ann_classification).

Asset Inventory
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Model
type: NamedIndividual
enables: Model
d3fend-id: D3-AI
definition: Asset inventorying identifies and records the organization's assets and enriches each inventory item with knowledge about their vulnerabilities.
display-order: 1
synonym: Asset Discovery
synonym: Asset Inventorying

Asset Inventory Agent
type: Class
subclass of: Network Agent
type: NamedIndividual
definition: An asset inventory agent is a software tool which captures and transmits information about the devices on a network, including their hostnames, MAC addresses, software they may be running, etc.

Asset Vulnerability Enumeration
type: Class
subclass of: Asset Inventory
subclass of: Restriction
  on property: evaluates
  some values from: Physical Artifact
subclass of: Restriction
  on property: evaluates
  some values from: Software
subclass of: Restriction
  on property: identifies
  some values from: Vulnerability
type: NamedIndividual
evaluates: Physical Artifact
evaluates: Software
identifies: Vulnerability
kb-reference: Reference-AutomatedComputerVulnerabilityResolutionSystem
kb-reference: Reference-SecurityVulnerabilityInformationAggregation
kb-reference: Reference-SystemAndMethodForVulnerabilityRiskAssessment
d3fend-id: D3-AVE
definition: Asset vulnerability enumeration enriches inventory items with knowledge identifying their vulnerabilities.

Assign Privileges to Group Event
type: Class
subclass of: Group Management Event
definition: An event where specific privileges or rights are granted to a group, enabling its members to perform actions or access resources as defined by the privileges.

Association Rule Learning
type: Class
subclass of: Unsupervised Learning
type: NamedIndividual
d3fend-id: D3A-ARL
definition: Association rule learning is a rule-based machine learning method for discovering interesting relations between variables in large databases.
kb-article: ## References Association rule learning. (n.d.). Wikipedia. [Link](https://en.wikipedia.org/wiki/Association_rule_learning)

Asymmetric Feature-based Transfer Learning
type: Class
subclass of: Homogenous Transfer Learning
type: NamedIndividual
d3fend-id: D3A-AFTL
definition: Homogeneous (where the metrics are the same for both source and target) asymmetric transformation mapping transforms the source feature space to align with that of the target or the target to that of the source. This, in effect, bridges the feature space gap and reduces the problem into a homogeneous transfer problem when further distribution differences need to be corrected.
kb-article: ## References Day, O., & Khoshgoftaar, T.M. (2017). A survey on heterogeneous transfer learning. Journal of Big Data, 4(1), 29. [Link](https://doi.org/10.1186/s40537-017-0089-0).

Asymmetric Key
type: Class
subclass of: Cryptographic Key
definition: Asymmetric keys are public and private keys, paired such that asymmetric (public-key) cryptography algorithms can be implemented using them. Public-key cryptography, or asymmetric cryptography, is any cryptographic system that uses pairs of keys: public keys that may be disseminated widely paired with private keys which are known only to the owner. There are two functions that can be achieved: using a public key to authenticate that a message originated with a holder of the paired private key; or encrypting a message with a public key to ensure that only the holder of the paired private key can decrypt it.

Audio Input Device
type: Class
subclass of: Input Device
type: NamedIndividual
definition: Audio input devices allow a user to send audio info to a computer for processing, recording, or carrying out commands. Devices such as microphones allow users to speak to the computer in order to record a voice message or navigate software. Aside from recording, audio input devices are also used with speech recognition software.

Authenticate User
type: Class
subclass of: System Call
subclass of: Restriction
  on property: authenticates
  some values from: User Account
type: NamedIndividual
authenticates: User Account

Authentication
type: Class
subclass of: Defensive Action
subclass of: Restriction
  on property: authenticates
  some values from: User
subclass of: Restriction
  on property: may-create
  some values from: Intranet Network Traffic
subclass of: Restriction
  on property: originates-from
  some values from: Physical Location
type: NamedIndividual
definition: A request-response comprising a user credential presentation to a system and a verification response.

Authentication Cache Invalidation
type: Class
subclass of: Credential Eviction
subclass of: Restriction
  on property: deletes
  some values from: Credential
type: NamedIndividual
deletes: Credential
kb-reference: Reference-SecureCachingOfServerCredentials DellProductsLP
kb-reference: Reference-SystemAndMethodForProvidingAnActivelyInvalidatedClient-sideNetworkResourceCache IMVU
d3fend-id: D3-ANCI
definition: Removing tokens or credentials from an authentication cache to prevent further user associated account accesses.
kb-article: ## How it works Applications can locally cache user authentication credentials for certain server connections. An application may attempt to use the cached credential for a connection. If the cached credentials exist then the user will not be typically prompted for new credentials. ## Considerations Are these cached credentials only on the local host? Can they be persisted to the remote server? ## Examples Windows Credential Management API

Authentication Event
type: Class
subclass of: Digital Event
subclass of: Restriction
  on property: caused-by
  some values from: Authentication
subclass of: Restriction
  on property: has-participant
  some values from: Agent
subclass of: Restriction
  on property: has-participant
  some values from: Credential
definition: An event capturing the systematic process of verifying an agent's identity within a system, involving credential validation and identity confirmation.
alternative label: Agent Authentication Event

Authentication Event Thresholding
type: Class
subclass of: User Behavior Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Authentication
type: NamedIndividual
analyzes: Authentication
kb-reference: Reference-MethodAndApparatusForNetworkFraudDetectionAndRemediationThroughAnalytics IdaptiveLLC
kb-reference: Reference-SimultaneousLoginsOnAHost MITRE
kb-reference: Reference-UserLoggedInToMultipleHosts MITRE
kb-reference: Reference-UserLoginActivityMonitoring MITRE
kb-reference: Reference-System,Method,AndComputerProgramProductForDetectingAndAssessingSecurityRisksInANetwork ExabeamInc
date created: 2020-08-05T00:00:00
d3fend-id: D3-ANET
definition: Collecting authentication events, creating a baseline user profile, and determining whether authentication events are consistent with the baseline profile.
kb-article: ## How it works Authentication event data is collected (logon information such as device id, time of day, day of week, geo-location, etc.) to create an activity baseline. Then, a threshold is determined either through a manually specified configuration, or a statistical analysis of deviations in historical data. New authentication events are evaluated to determine if a threshold is exceeded. Thresholds can be static or dynamic. ### Actions As a result of the analysis, actions taken could include: * [Account Locking](/technique/d3f:AccountLocking) * Raising an alert ### Example data sources * Directory server logs * VPN Server logs * IDAM Capability logs * NAC logs * Authentication client logs * Kerberos network traffic * LDAP network traffic ## Considerations This technique covers statistical outliers. Though depending on the complexity or dimensionality of the data considered, outliers may not be obvious to a human analyst reviewing events in simplistic analytic views. If the malicious activity is not statistically different from benign activity, an alert threshold will not be met.

Authentication Function
type: Class
subclass of: Subroutine
subclass of: Restriction
  on property: authenticates
  some values from: User Account
type: NamedIndividual
authenticates: User Account
definition: Authenticates a user account by verifying a presented credential.

Authentication Log
type: Class
subclass of: Event Log
subclass of: Restriction
  on property: records
  some values from: Authentication
type: NamedIndividual
records: Authentication
definition: A log of authentication events.

Authentication Server
type: Class
subclass of: Server
definition: An authentication server provides a network service that applications use to authenticate the credentials, usually account names and passwords, of their users. When a client submits a valid set of credentials, it receives a cryptographic ticket that it can subsequently use to access various services. Major authentication algorithms include passwords, Kerberos, and public key encryption.

Authentication Service
type: Class
subclass of: Service Application Process
type: NamedIndividual
definition: An authentication service is a mechanism, analogous to the use of passwords on time-sharing systems, for the secure authentication of the identity of network clients by servers and vice versa, without presuming the operating system integrity of either (e.g., Kerberos).

Authorization
type: Class
subclass of: Defensive Action
subclass of: Restriction
  on property: authorizes
  some values from: Access
type: NamedIndividual
definition: Authorization is the function of specifying access rights to resources related to information security and computer security in general and to access control in particular. More formally, "to authorize" is to define an access policy. For example, human resources staff is normally authorized to access employee records and this policy is usually formalized as access control rules in a computer system. During operation, the system uses the access control rules to decide whether access requests from (authenticated) consumers shall be approved (granted) or disapproved (rejected). Resources include individual files or an item's data, computer programs, computer devices and functionality provided by computer applications. Examples of consumers are computer users, computer program

Authorization Event
type: Class
subclass of: Digital Event
subclass of: Restriction
  on property: caused-by
  some values from: Authorization
subclass of: Restriction
  on property: has-participant
  some values from: Agent
definition: An event reflecting the decision-making process and actions concerning access control, recording whether agents are permitted or denied access to resources based on pre-defined access control policies.

Authorization Event Thresholding
type: Class
subclass of: User Behavior Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Authorization
type: NamedIndividual
analyzes: Authorization
kb-reference: Reference-MethodAndApparatusForNetworkFraudDetectionAndRemediationThroughAnalytics IdaptiveLLC
kb-reference: Reference-SMBSessionSetups MITRE
kb-reference: Reference-UserLoggedInToMultipleHosts MITRE
kb-reference: Reference-System,Method,AndComputerProgramProductForDetectingAndAssessingSecurityRisksInANetwork ExabeamInc
date created: 2020-08-05T00:00:00
d3fend-id: D3-AZET
definition: Collecting authorization events, creating a baseline user profile, and determining whether authorization events are consistent with the baseline profile.
kb-article: ## How it works Authorization event data is collected to create a baseline user profile. Authorization events that deviate from the baseline and exceed a static or dynamic threshold are identified for further action. Authorization events can include successful and failed authorization attempts as well as events related to permissions including viewing, editing, deleting, creating files, databases etc. ## Considerations Depending on the complexity of the data considered, outliers may not be obvious to a human analyst reviewing events in simplistic analytic views. If malicious activity is not statistically different from benign activity, an alert threshold will not be met.

Authorization Log
type: Class
subclass of: Event Log
subclass of: Restriction
  on property: records
  some values from: Network Resource Access
type: NamedIndividual
records: Network Resource Access
definition: A log of authorization events.

Authorization Service
type: Class
subclass of: Network Service
subclass of: Service Application Process
definition: An authorization service ensures that the user is authorized to have access to a particular resource. Authorization can be done through role-based access control (RBAC) or list-based access control (LBAC).

Autoencoding
type: Class
subclass of: Dimension Reduction
type: NamedIndividual
d3fend-id: D3A-AUT
definition: Autoencoders are specific type of deep learning architecture used for learning representation of data, typically for the purpose of dimensionality reduction. This is achieved by designing deep learning architecture that aims that copying input layer at its output layer.
kb-article: ## References SOCR. (n.d.). ABIDE Autoencoder. [Link](https://socr.umich.edu/HTML5/ABIDE_Autoencoder/#:~:text=In%20simple%20words%2C%20autoencoders%20are,layer%20at%20its%20output%20layer.)

Autoregressive Model
type: Class
subclass of: Time Series Analysis
type: NamedIndividual
d3fend-id: D3A-AM
definition: An autoregressive (AR) model is a representation of a type of random process; as such, it is used to describe certain time-varying processes in nature, economics, behavior, etc.
kb-article: ## References Wikipedia. (n.d.). Autoregressive model. [Link](https://en.wikipedia.org/wiki/Autoregressive_model)
synonym: AR Model

Average Absolute Deviation
type: Class
subclass of: Variability
type: NamedIndividual
d3fend-id: D3A-AAD
definition: The average absolute deviation (AAD) of a data set is the average of the absolute deviations from a central point.
kb-article: ## References Wikipedia. (n.d.). Average absolute deviation. [Link](https://en.wikipedia.org/wiki/Average_absolute_deviation)

BERT
type: Class
subclass of: Transformer-based Learning
type: NamedIndividual
d3fend-id: D3A-BER
definition: Bidirectional Encoder Representations from Transformers (BERT) is based on a deep learning model in which every output element is connected to every input element, and the weightings between them are dynamically calculated based upon their connection.
kb-article: ## References BERT (language model). (n.d.). In TechTarget. [Link](https://www.techtarget.com/searchenterpriseai/definition/BERT-language-model) BERT (language model). (n.d.). In Wikipedia. [Link](https://en.wikipedia.org/wiki/BERT_(language_model))
synonym: Bidirectional Encoder Representations from Transformers

Barcode Scanner Input Device
type: Class
subclass of: Image Scanner Input Device
definition: A barcode reader (or barcode scanner) is an optical scanner that can read printed barcodes, decode the data contained in the barcode and send the data to a computer. Like a flatbed scanner, it consists of a light source, a lens and a light sensor translating for optical impulses into electrical signals. Additionally, nearly all barcode readers contain decoder circuitry that can analyze the barcode's image data provided by the sensor and sending the barcode's content to the scanner's output port.
alternative label: Barcode Reader

Bayes Optimal Classifier
type: Class
subclass of: Ensemble Learning
type: NamedIndividual
d3fend-id: D3A-BOC
definition: A probabilistic model that makes the most probable prediction for a new example.
kb-article: ## References Bayes Optimal Classifier. Machine Learning Mastery. [Link](https://machinelearningmastery.com/bayes-optimal-classifier/). Ensemble learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Ensemble_learning).

Bayesian Estimation
type: Class
subclass of: Bayesian Method
type: NamedIndividual
d3fend-id: D3A-BE
definition: A Bayes estimator or a Bayes action is an estimator or decision rule that minimizes the posterior expected value of a loss function (i.e., the posterior expected loss).
kb-article: ## References Wikipedia. (n.d.). Bayes estimator. [Link](https://en.wikipedia.org/wiki/Bayes_estimator)

Bayesian Hypothesis Testing
type: Class
subclass of: Bayesian Method
type: NamedIndividual
d3fend-id: D3A-BHT
definition: Bayesian hypothesis testing can be framed as a special case of model comparison where a model refers to a likelihood function and a prior distribution.
kb-article: ## How it works Given two competing hypotheses and some relevant data, Bayesian hypothesis testing begins by specifying separate prior distributions to quantitatively describe each hypothesis. The combination of the likelihood function for the observed data with each of the prior distributions yields hypothesis-specific models. For each of the hypothesis-specific models, averaging (ie, integrating) the likelihood with respect to the prior distribution across the entire parameter space yields the probability of the data under the model and, therefore, the corresponding hypothesis. This quantity is more commonly referred to as the marginal likelihood and represents the average fit of the model to the data. The ratio of the marginal likelihoods for both hypothesis-specific models is known as the Bayes factor. ## References Baig, S. A., PhD. (2020). Bayesian Inference: An Introduction to Hypothesis Testing Using Bayes Factors. Nicotine & Tobacco Research, 22(7), 1244-1246. [Link](https://academic.oup.com/ntr/article/22/7/1244/5613971)

Bayesian Linear Regression
type: Class
subclass of: Regression Analysis
type: NamedIndividual
d3fend-id: D3A-BLR
definition: Bayesian linear regression is a type of conditional modeling in which the mean of one variable is described by a linear combination of other variables, with the goal of obtaining the posterior probability of the regression coefficients.
kb-article: ## References Wikipedia. (n.d.). Bayesian linear regression. [Link](https://en.wikipedia.org/wiki/Bayesian_linear_regression)

Bayesian Linear Regression Learning
type: Class
subclass of: Regression Analysis Learning
type: NamedIndividual
d3fend-id: D3A-BLRL
definition: A supervised learning method that builds a Bayesian linear regression model using training data.
kb-article: ## References Wikipedia. (n.d.). Bayesian linear regression. [Link](https://en.wikipedia.org/wiki/Bayesian_linear_regression)

Bayesian Method
type: Class
subclass of: Statistical Method
type: NamedIndividual
d3fend-id: D3A-BM
definition: Bayesian analysis is a statistical procedure which endeavors to estimate parameters of an underlying distribution based on the observed distribution.
kb-article: ## References Wolfram MathWorld. (n.d.). Bayesian Analysis. [Link](https://mathworld.wolfram.com/BayesianAnalysis.html)

Bayesian Model Averaging
type: Class
subclass of: Ensemble Learning
type: NamedIndividual
d3fend-id: D3A-BMA
definition: A parameter estimate (or a prediction of new observations) obtained by averaging the estimates (or predictions) of the different models under consideration, each weighted by its model probability.
kb-article: ## References Ensemble learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Ensemble_learning). Bayesian model average: A parameter estimation approach to model agnostic ensemble learning. (2019). Journal of Machine Learning for Modeling and Computing, 1(2), 61-70. [Link](https://journals.sagepub.com/doi/full/10.1177/2515245919898657#:~:text=Bayesian%20model%20average%3A%20A%20parameter,weighted%20by%20its%20model%20probability).

Bayesian Model Combination
type: Class
subclass of: Ensemble Learning
type: NamedIndividual
d3fend-id: D3A-BMC
definition: Bayesian model combination (BMC) is an algorithmic correction to Bayesian model averaging (BMA). Instead of sampling each model in the ensemble individually, it samples from the space of possible ensembles (with model weights drawn randomly from a Dirichlet distribution having uniform parameters)
kb-article: ## References Ensemble learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Ensemble_learning). Shultz, K. M., & Peterson, L. E. (2011). Model-averaged confidence intervals for ensemble learning. In *International Joint Conference on Neural Networks* (pp. 2677-2684). [Link](https://axon.cs.byu.edu/papers/Kristine.ijcnn2011.pdf).

Binary Classification
type: Class
subclass of: Classifying

Binary Large Object
type: Class
subclass of: Digital Information Bearer
definition: A binary large object (BLOB) is a collection of binary data stored as a single entity. Blobs are typically images, audio or other multimedia objects, though sometimes binary executable code is stored as a blob.
alternative label: BLOB
alternative label: Blob

Binary Segment
type: Class
subclass of: Digital Information Bearer
definition: A binary segment is a partition of binary information within a larger binary object, which arranges a set of binary objects for its purpose. For example, code, data, heap, and stack segments are segments of the binary information used by a process. Code and data segments are also found in object files.

Biometric Authentication
type: Class
subclass of: Agent Authentication
subclass of: Restriction
  on property: authenticates
  some values from: Person
type: NamedIndividual
authenticates: Person
kb-reference: Reference-TokenlessBiometricTransactionAuthorizationMethodAndSystem
kb-reference: Reference-www.biometric-solutions.com keystroke-dynamics
d3fend-id: D3-BAN
definition: Using biological measures in order to authenticate a user.

Block Device
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: contains
  some values from: Boot Sector
subclass of: Restriction
  on property: contains
  some values from: Partition
subclass of: Restriction
  on property: contains
  some values from: Partition Table
subclass of: Restriction
  on property: may-contain
  some values from: Volume
type: NamedIndividual
contains: Boot Sector
contains: Partition
contains: Partition Table
may-contain: Volume
definition: A block device (or block special file) provides buffered access to hardware devices, and provides some abstraction from their specifics. IEEE Std 1003.1-2017: A file that refers to a device. A block special file is normally distinguished from a character special file by providing access to the device in a manner such that the hardware characteristics of the device are not visible.
alternative label: Block Special File

Book Reference
type: Class
subclass of: Technique Reference
pref-label: Book

Boolean Expression Matching
type: Class
subclass of: Logical Rules
type: NamedIndividual
d3fend-id: D3A-BEM
definition: Boolean expression matching produces a Boolean truth value for a given boolean expression and assignment of values to variables in the expression.
kb-article: ## How it works A Boolean expression is an expression used in programming languages that produces a Boolean value when evaluated. A Boolean value is either true or false. A Boolean expression may be composed of a combination of the Boolean constants true or false, Boolean-typed variables, Boolean-valued operators, and Boolean-valued functions. Boolean expressions correspond to propositional formulas in logic and are a special case of Boolean circuits. ## References 1. Boolean expression. (2022, April 25). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Boolean_expression) 2. Boolean algebra. (2022, May 19). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Boolean_expression)

Boosting
type: Class
subclass of: Ensemble Learning
type: NamedIndividual
d3fend-id: D3A-BOO
definition: Boosting is a sequential process where each subsequent model attempts to correct the errors of the previous model
kb-article: ## How it works Boosting consists of using sequentially weak learners where each iteration’s training focuses on previously misclassified instances in order to improve on the previous iteration. This process is continued iteratively until the final prediction is made by aggregating the previous predictions. ## Considerations Boosting can be computationally expensive, prone to overfitting, and slower to train compared to other ensemble methods. There are three main types of Boosting algorithms - Adaptive Boosting Adaptive Boosting (sometimes called AdaBoost) works by adding equal importance to each piece of a dataset and running it through the base learning algorithms. Every algorithm that errors, the boosting algorithm assigns a higher importance to. This continues until an acceptable level of confidence is reached. - Gradient Boosting Gradient Boosting starts by training multiple models simultaneously to gather a strong estimate of strength to build new base learning algorithms. - XGBoosting XGBoosting is a scalable tree boosting model. Using decision trees, weight is assigned to each variable and put into a decision tree. Outputs that are classified by the algorithm as wrong or weak are put into a second decision tree and the results form a stronger model. ## References Sciencedirect. (n.d.). Semi-supervised learning: An overview. [Link](https://www.sciencedirect.com/science/article/pii/S1319157823000228)

Boot Loader
type: Class
subclass of: Software
type: NamedIndividual
definition: A bootloader is software that is responsible for booting a computer. When a computer is turned off, its software‍-‌including operating systems, application code, and data‍-‌remains stored on non-volatile memory. When the computer is powered on, it typically does not have an operating system or its loader in random-access memory (RAM). The computer first executes a relatively small program stored in read-only memory (ROM, and later EEPROM, NOR flash) along with some needed data, to initialize RAM (especially on x86 systems) to access the nonvolatile device (usually block device, eg NAND flash) or devices from which the operating system programs and data can be loaded into RAM.
alternative label: Bootloader

Boot Record
type: Class
subclass of: Record
type: NamedIndividual
definition: A d3f:Record which is an essential component of the early boot (system initialization) process.

Boot Sector
type: Class
subclass of: Boot Record
type: NamedIndividual
definition: A boot record [boot sector] is the sector of a persistent data storage device (e.g., hard disk, floppy disk, optical disc, etc.) which contains machine code to be loaded into random-access memory (RAM) and then executed by a computer system's built-in firmware (e.g., the BIOS, Das U-Boot, etc.).

Bootloader Authentication
type: Class
subclass of: Platform Hardening
subclass of: Restriction
  on property: authenticates
  some values from: Boot Loader
type: NamedIndividual
authenticates: Boot Loader
kb-reference: Reference-UEFIPlatformInitialization-Specification
d3fend-id: D3-BA
definition: Cryptographically authenticating the bootloader software before system boot.
synonym: Secure Boot

Bootstrap Aggregating
type: Class
subclass of: Resampling Ensemble
type: NamedIndividual
d3fend-id: D3A-BA
definition: Bootstrap aggregating, also called bagging (from bootstrap aggregating), is a machine learning ensemble meta-algorithm designed to improve the stability and accuracy of machine learning algorithms used in statistical classification and regression. It also reduces variance and helps to avoid overfitting. Although it is usually applied to decision tree methods, it can be used with any type of method. Bagging is a special case of the model averaging approach.
kb-article: ## References Bootstrap aggregating. Wikipedia. [Link](https://en.wikipedia.org/wiki/Bootstrap_aggregating).

Broadcast Domain Isolation
type: Class
subclass of: Network Isolation
subclass of: Restriction
  on property: filters
  some values from: Local Area Network Traffic
type: NamedIndividual
filters: Local Area Network Traffic
kb-reference: Reference-PrivateVirtualLocalAreaNetworkIsolation CiscoTechnologyInc
d3fend-id: D3-BDI
definition: Broadcast isolation restricts the number of computers a host can contact on their LAN.
kb-article: ## How it works Software Defined Networking, or other network encapsulation technologies intercept host broadcast traffic then route it to a specified destination per a configured policy. This can be implemented within hypervisors, networking hardware (WAPs, switches, routers), or virutal hardware. ## Considerations This technique is highly dependent on network infrastructure and networking requirements.
synonym: Network Segmentation

Browser
type: Class
subclass of: User Application
subclass of: Restriction
  on property: may-contain
  some values from: Browser Extension
type: NamedIndividual
may-contain: Browser Extension
definition: A web browser (commonly referred to as a browser) is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier (URI/URL) and may be a web page, image, video or other piece of content. Hyperlinks present in resources enable users easily to navigate their browsers to related resources. Although browsers are primarily intended to use the World Wide Web, they can also be used to access information provided by web servers in private networks or files in file systems.

Browser Extension
type: Class
subclass of: User Application
subclass of: Restriction
  on property: extends
  some values from: Browser
type: NamedIndividual
extends: Browser
definition: A browser extension is a plug-in that extends the functionality of a web browser in some way. Some extensions are authored using web technologies such as HTML, JavaScript, and CSS. Browser extensions can change the user interface of the web browser without directly affecting viewable content of a web page; for example, by adding a "toolbar."

Bucket of Models
type: Class
subclass of: Ensemble Learning
type: NamedIndividual
d3fend-id: D3A-BOM
definition: A "bucket of models" is an ensemble technique in which a model selection algorithm is used to choose the best model for each problem. When tested with only one problem, a bucket of models can produce no better results than the best model in the set, but when evaluated across many problems, it will typically produce much better results, on average, than any model in the set.
kb-article: ## References Ensemble learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Ensemble_learning).

Build Tool
type: Class
subclass of: Developer Application
definition: A tool that automates the process of creating a software build and the associated processes including: compiling computer source code into binary code, packaging binary code, and running automated tests.
alternative label: Build Automation Tool

Business Communication Platform Client
type: Class
subclass of: Collaborative Software
definition: Client software to enable the process of sharing information between employees within and outside a company. Business communication encompasses topics such as marketing, brand management, customer relations, consumer behavior, advertising, public relations, corporate communication, community engagement, reputation management, interpersonal communication, employee engagement, and event management. It is closely related to the fields of professional communication and technical communication.

Byte Sequence Emulation
type: Class
subclass of: Network Traffic Analysis
type: NamedIndividual
kb-reference: Reference-Network-BasedBufferOverflowDetectionByExploitCodeAnalysis InformationSecurityResearchCentre
kb-reference: Reference-Network-levelPolymorphicShellcodeDetectionUsingEmulation
d3fend-id: D3-BSE
definition: Analyzing sequences of bytes and determining if they likely represent malicious shellcode.
kb-article: ## How it works Bytes are analyzed as if they are machine code instructions, and such instructions that are a common component of known shellcode are noted, such as stack pivots, reads from a Memory Address Table, and system calls for functions that disable protections or execute code. For example, the x86 instruction `b0 0b: mov $11, %ax`, with no further alterations to the `%ax` register, followed by `cd 80: syscall` executes the system call `execve()` in the Linux kernel, which replaces the current process with another one specified -- this is a common action in shellcode, so this sequence would be flagged. This technique detects shellcode despite whether or not it would cause a buffer overflow in the target binary. If the sequence of bytes contains a sequence similar to that used in malicious shellcode, the entire byte sequence is flagged and a follow-on technique may be invoked. ## Considerations ### False Negatives If the shellcode instructions are far apart, simple implementations might not detect the shellcode. Due to the nature of assembly instructions not having a defined start or end, implementations which do not process all start sequences (for example, when they a find byte sequence of interest, continue scanning forwards from the end of it) might not detect the shellcode. This technique might not detect more complex or obfuscated instructions. For that purpose, Dynamic Analysis or Emulated File Analysis could assist by analyzing the actual instruction function. This technique may not detect self-modifying code. To make it harder for a process to modify itself, Process Segment Execution Prevention should be used, while noting its considerations. This technique might not detect malicious shellcode which reuses instructions in the target binary for malicious effect, as memory references in the presumed assembly code are not dereferenced. Dynamic Analysis and Emulated File Analysis, when set up properly to fork from the running target binary, might detect …
synonym: Shellcode Transmission Detection

C4.5
type: Class
subclass of: Decision Tree
type: NamedIndividual
d3fend-id: D3A-C4.
definition: C4.5 is an algorithm that is strongly based off ID3. It creates decision trees the same way as ID3. C4.5 improves on several aspects of ID3, including handling discreet variables, handling training data with missing values, and has the ability to automatically prune the decision trees it creates.
kb-article: ## References C4.5 algorithm. Wikipedia. [Link](https://en.wikipedia.org/wiki/C4.5_algorithm).

C5.0
type: Class
subclass of: Decision Tree
type: NamedIndividual
d3fend-id: D3A-C5.
definition: C5.0 is the next version of C4.5, which in turn is the upgrade from ID3. The only difference between C5.0 and C4.5 is some improvements made to C5.0.
kb-article: ## References C4.5 algorithm. Wikipedia. [Link](https://en.wikipedia.org/wiki/C4.5_algorithm).

CA Certificate File
type: Class
subclass of: Certificate File
definition: A file containing a digital certificate issued by a certificate authority (CA). Certificate authorities store, issue, and sign digital certificates used as part of the public key infrastructure.

Exploitation of Transient Instruction Execution
type: Class
subclass of: Common Attack Pattern
type: NamedIndividual
type: Common Attack Pattern
capec-id: CAPEC-553

CAPEC Thing
type: Class
subclass of: External Threat Model Thing

CART
type: Class
subclass of: Decision Tree
type: NamedIndividual
d3fend-id: D3A-CAR
definition: The CART algorithm is a type of classification algorithm that is required to build a decision tree on the basis of Gini’s impurity index.
kb-article: ## References Classification and Regression Tree (CART) Algorithm. Analytics Steps. [Link](https://www.analyticssteps.com/blogs/classification-and-regression-tree-cart-algorithm).

CCI Control
type: Class
subclass of: External Control
subclass of: Restriction
  on property: member-of
  some values from: Control Correlation Identifier Catalog
subclass of: Restriction
  on property: control-name
  some values from: string
subclass of: Restriction
  on property: date published
  some values from: dateTime

Sensitive Cookie Without 'HttpOnly' Flag
type: Class
subclass of: Incorrect Permission Assignment for Critical Resource
cwe-id: CWE-1004

Insufficient Visual Distinction of Homoglyphs Presented to User
type: Class
subclass of: User Interface (UI) Misrepresentation of Critical Information
cwe-id: CWE-1007

Struts: Duplicate Validation Forms
type: Class
subclass of: Improper Use of Validation Framework
subclass of: Use of Multiple Resources with Duplicate Identifier
cwe-id: CWE-102

Improper Restriction of Rendered UI Layers or Frames
type: Class
subclass of: Unintended Proxy or Intermediary ('Confused Deputy')
subclass of: User Interface (UI) Misrepresentation of Critical Information
cwe-id: CWE-1021

Use of Web Link to Untrusted Target with window.opener Access
type: Class
subclass of: Incorrect Privilege Assignment
cwe-id: CWE-1022

Incomplete Comparison with Missing Factors
type: Class
subclass of: Incorrect Comparison
cwe-id: CWE-1023

Comparison of Incompatible Types
type: Class
subclass of: Incorrect Comparison
cwe-id: CWE-1024

Comparison Using Wrong Factors
type: Class
subclass of: Incorrect Comparison
cwe-id: CWE-1025

Struts: Incomplete validate() Method Definition
type: Class
subclass of: Improper Following of Specification by Caller
cwe-id: CWE-103

Processor Optimization Removal or Modification of Security-critical Code
type: Class
subclass of: Insecure Automated Optimizations
cwe-id: CWE-1037

Insecure Automated Optimizations
type: Class
subclass of: Improper Interaction Between Multiple Correctly-Behaving Entities
subclass of: Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
cwe-id: CWE-1038

Automated Recognition Mechanism with Inadequate Detection or Handling of Adversarial Input Perturbations
type: Class
subclass of: Protection Mechanism Failure
subclass of: Incorrect Comparison
cwe-id: CWE-1039

Struts: Form Bean Does Not Extend Validation Class
type: Class
subclass of: Improper Following of Specification by Caller
cwe-id: CWE-104

Use of Redundant Code
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1041

Static Member Data Element outside of a Singleton Class Element
type: Class
subclass of: Inefficient CPU Computation
cwe-id: CWE-1042

Data Element Aggregating an Excessively Large Number of Non-Primitive Elements
type: Class
subclass of: Excessively Complex Data Representation
cwe-id: CWE-1043

Architecture with Number of Horizontal Layers Outside of Expected Range
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1044

Parent Class with a Virtual Destructor and a Child Class without a Virtual Destructor
type: Class
subclass of: Insufficient Adherence to Expected Conventions
cwe-id: CWE-1045

Creation of Immutable Text Using String Concatenation
type: Class
subclass of: Inefficient CPU Computation
cwe-id: CWE-1046

Modules with Circular Dependencies
type: Class
subclass of: Excessive Code Complexity
cwe-id: CWE-1047

Invokable Control Element with Large Number of Outward Calls
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1048

Excessive Data Query Operations in a Large Data Table
type: Class
subclass of: Inefficient CPU Computation
cwe-id: CWE-1049

Struts: Form Field Without Validator
type: Class
subclass of: Improper Use of Validation Framework
cwe-id: CWE-105

Excessive Platform Resource Consumption within a Loop
type: Class
subclass of: Asymmetric Resource Consumption (Amplification)
cwe-id: CWE-1050

Initialization with Hard-Coded Network Resource Configuration Data
type: Class
subclass of: Improper Initialization
cwe-id: CWE-1051

Excessive Use of Hard-Coded Literals in Initialization
type: Class
subclass of: Improper Initialization
cwe-id: CWE-1052

Missing Documentation for Design
type: Class
subclass of: Insufficient Technical Documentation
cwe-id: CWE-1053

Invocation of a Control Element at an Unnecessarily Deep Horizontal Layer
type: Class
subclass of: Insufficient Encapsulation
cwe-id: CWE-1054

Multiple Inheritance from Concrete Classes
type: Class
subclass of: Excessively Complex Data Representation
cwe-id: CWE-1055

Invokable Control Element with Variadic Parameters
type: Class
subclass of: Excessive Code Complexity
cwe-id: CWE-1056

Data Access Operations Outside of Expected Data Manager Component
type: Class
subclass of: Insufficient Encapsulation
cwe-id: CWE-1057

Invokable Control Element in Multi-Thread Context with non-Final Static Storable or Member Element
type: Class
subclass of: Improper Synchronization
cwe-id: CWE-1058

Insufficient Technical Documentation
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1059

Struts: Plug-in Framework not in Use
type: Class
subclass of: Improper Use of Validation Framework
cwe-id: CWE-106

Excessive Number of Inefficient Server-Side Data Accesses
type: Class
subclass of: Excessive Code Complexity
cwe-id: CWE-1060

Insufficient Encapsulation
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1061

Parent Class with References to Child Class
type: Class
subclass of: Insufficient Encapsulation
cwe-id: CWE-1062

Creation of Class Instance within a Static Code Block
type: Class
subclass of: Inefficient CPU Computation
cwe-id: CWE-1063

Invokable Control Element with Signature Containing an Excessive Number of Parameters
type: Class
subclass of: Excessive Code Complexity
cwe-id: CWE-1064

Runtime Resource Management Control Element in a Component Built to Run on Application Servers
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1065

Missing Serialization Control Element
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1066

Excessive Execution of Sequential Searches of Data Resource
type: Class
subclass of: Inefficient CPU Computation
cwe-id: CWE-1067

Inconsistency Between Implementation and Documented Design
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1068

Empty Exception Block
type: Class
subclass of: Empty Code Block
cwe-id: CWE-1069

Struts: Unused Validation Form
type: Class
subclass of: Irrelevant Code
cwe-id: CWE-107

Serializable Data Element Containing non-Serializable Item Elements
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1070

Empty Code Block
type: Class
subclass of: Irrelevant Code
cwe-id: CWE-1071

Data Resource Access without Use of Connection Pooling
type: Class
subclass of: Asymmetric Resource Consumption (Amplification)
cwe-id: CWE-1072

Non-SQL Invokable Control Element with Excessive Number of Data Resource Accesses
type: Class
subclass of: Asymmetric Resource Consumption (Amplification)
cwe-id: CWE-1073

Class with Excessively Deep Inheritance
type: Class
subclass of: Excessively Complex Data Representation
cwe-id: CWE-1074

Unconditional Control Flow Transfer outside of Switch Block
type: Class
subclass of: Excessive Code Complexity
cwe-id: CWE-1075

Insufficient Adherence to Expected Conventions
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1076

Floating Point Comparison with Incorrect Operator
type: Class
subclass of: Incorrect Comparison
cwe-id: CWE-1077

Inappropriate Source Code Style or Formatting
type: Class
subclass of: Insufficient Adherence to Expected Conventions
cwe-id: CWE-1078

Parent Class without Virtual Destructor Method
type: Class
subclass of: Insufficient Adherence to Expected Conventions
cwe-id: CWE-1079

Struts: Unvalidated Action Form
type: Class
subclass of: Improper Use of Validation Framework
cwe-id: CWE-108

Source Code File with Excessive Number of Lines of Code
type: Class
subclass of: Excessive Code Complexity
cwe-id: CWE-1080

Class Instance Self Destruction Control Element
type: Class
subclass of: Insufficient Adherence to Expected Conventions
cwe-id: CWE-1082

Data Access from Outside Expected Data Manager Component
type: Class
subclass of: Insufficient Encapsulation
cwe-id: CWE-1083

Invokable Control Element with Excessive File or Data Access Operations
type: Class
subclass of: Asymmetric Resource Consumption (Amplification)
cwe-id: CWE-1084

Invokable Control Element with Excessive Volume of Commented-out Code
type: Class
subclass of: Inappropriate Source Code Style or Formatting
cwe-id: CWE-1085

Class with Excessive Number of Child Classes
type: Class
subclass of: Excessively Complex Data Representation
cwe-id: CWE-1086

Class with Virtual Method without a Virtual Destructor
type: Class
subclass of: Insufficient Adherence to Expected Conventions
cwe-id: CWE-1087

Synchronous Access of Remote Resource without Timeout
type: Class
subclass of: Incorrect Synchronization
cwe-id: CWE-1088

Large Data Table with Excessive Number of Indices
type: Class
subclass of: Asymmetric Resource Consumption (Amplification)
cwe-id: CWE-1089

Struts: Validator Turned Off
type: Class
subclass of: Improper Use of Validation Framework
cwe-id: CWE-109

Method Containing Access of a Member Element from Another Class
type: Class
subclass of: Insufficient Encapsulation
cwe-id: CWE-1090

Use of Object without Invoking Destructor Method
type: Class
subclass of: Insufficient Adherence to Expected Conventions
subclass of: Missing Release of Resource after Effective Lifetime
cwe-id: CWE-1091

Use of Same Invokable Control Element in Multiple Architectural Layers
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1092

Excessively Complex Data Representation
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1093

Excessive Index Range Scan for a Data Resource
type: Class
subclass of: Asymmetric Resource Consumption (Amplification)
cwe-id: CWE-1094

Loop Condition Value Update within the Loop
type: Class
subclass of: Excessive Code Complexity
cwe-id: CWE-1095

Singleton Class Instance Creation without Proper Locking or Synchronization
type: Class
subclass of: Missing Synchronization
cwe-id: CWE-1096

Persistent Storable Data Element without Associated Comparison Control Element
type: Class
subclass of: Insufficient Adherence to Expected Conventions
cwe-id: CWE-1097

Data Element containing Pointer Item without Proper Copy Control Element
type: Class
subclass of: Insufficient Adherence to Expected Conventions
cwe-id: CWE-1098

Inconsistent Naming Conventions for Identifiers
type: Class
subclass of: Inappropriate Source Code Style or Formatting
cwe-id: CWE-1099

ASP.NET Misconfiguration: Creating Debug Binary
type: Class
subclass of: Active Debug Code
cwe-id: CWE-11

Struts: Validator Without Form Field
type: Class
subclass of: Irrelevant Code
cwe-id: CWE-110

Insufficient Isolation of System-Dependent Functions
type: Class
subclass of: Insufficient Encapsulation
cwe-id: CWE-1100

Reliance on Runtime Component in Generated Code
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1101

Reliance on Machine-Dependent Data Representation
type: Class
subclass of: Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
cwe-id: CWE-1102

Use of Platform-Dependent Third Party Components
type: Class
subclass of: Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
cwe-id: CWE-1103

Use of Unmaintained Third Party Components
type: Class
subclass of: Reliance on Insufficiently Trustworthy Component
cwe-id: CWE-1104

Insufficient Encapsulation of Machine-Dependent Functionality
type: Class
subclass of: Insufficient Encapsulation
subclass of: Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
cwe-id: CWE-1105

Insufficient Use of Symbolic Constants
type: Class
subclass of: Inappropriate Source Code Style or Formatting
cwe-id: CWE-1106

Insufficient Isolation of Symbolic Constant Definitions
type: Class
subclass of: Inappropriate Source Code Style or Formatting
cwe-id: CWE-1107

Excessive Reliance on Global Variables
type: Class
subclass of: Insufficient Adherence to Expected Conventions
cwe-id: CWE-1108

Use of Same Variable for Multiple Purposes
type: Class
subclass of: Inappropriate Source Code Style or Formatting
cwe-id: CWE-1109

Direct Use of Unsafe JNI
type: Class
subclass of: Use of Low-Level Functionality
cwe-id: CWE-111

Incomplete Design Documentation
type: Class
subclass of: Insufficient Technical Documentation
cwe-id: CWE-1110

Incomplete I/O Documentation
type: Class
subclass of: Insufficient Technical Documentation
cwe-id: CWE-1111

Incomplete Documentation of Program Execution
type: Class
subclass of: Insufficient Technical Documentation
cwe-id: CWE-1112

Inappropriate Comment Style
type: Class
subclass of: Inappropriate Source Code Style or Formatting
cwe-id: CWE-1113

Inappropriate Whitespace Style
type: Class
subclass of: Inappropriate Source Code Style or Formatting
cwe-id: CWE-1114

Source Code Element without Standard Prologue
type: Class
subclass of: Inappropriate Source Code Style or Formatting
cwe-id: CWE-1115

Inaccurate Comments
type: Class
subclass of: Inappropriate Source Code Style or Formatting
cwe-id: CWE-1116

Callable with Insufficient Behavioral Summary
type: Class
subclass of: Inappropriate Source Code Style or Formatting
cwe-id: CWE-1117

Insufficient Documentation of Error Handling Techniques
type: Class
subclass of: Insufficient Technical Documentation
cwe-id: CWE-1118

Excessive Use of Unconditional Branching
type: Class
subclass of: Excessive Code Complexity
cwe-id: CWE-1119

Missing XML Validation
type: Class
subclass of: Improper Validation of Syntactic Correctness of Input
cwe-id: CWE-112

Excessive Code Complexity
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1120

Excessive McCabe Cyclomatic Complexity
type: Class
subclass of: Excessive Code Complexity
cwe-id: CWE-1121

Excessive Halstead Complexity
type: Class
subclass of: Excessive Code Complexity
cwe-id: CWE-1122

Excessive Use of Self-Modifying Code
type: Class
subclass of: Excessive Code Complexity
cwe-id: CWE-1123

Excessively Deep Nesting
type: Class
subclass of: Excessive Code Complexity
cwe-id: CWE-1124

Excessive Attack Surface
type: Class
subclass of: Excessive Code Complexity
cwe-id: CWE-1125

Declaration of Variable with Unnecessarily Wide Scope
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1126

Compilation with Insufficient Warnings or Errors
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1127

Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')
type: Class
subclass of: Interpretation Conflict
subclass of: Improper Neutralization of CRLF Sequences ('CRLF Injection')
cwe-id: CWE-113

Process Control
type: Class
subclass of: External Control of File Name or Path
cwe-id: CWE-114

Misinterpretation of Input
type: Class
subclass of: Interpretation Conflict
cwe-id: CWE-115

Improper Encoding or Escaping of Output
type: Class
subclass of: Improper Neutralization
cwe-id: CWE-116

Irrelevant Code
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1164

Improper Output Neutralization for Logs
type: Class
subclass of: Improper Encoding or Escaping of Output
cwe-id: CWE-117

Improper Use of Validation Framework
type: Class
subclass of: Improper Input Validation
cwe-id: CWE-1173

ASP.NET Misconfiguration: Improper Model Validation
type: Class
subclass of: Improper Use of Validation Framework
cwe-id: CWE-1174

Inefficient CPU Computation
type: Class
subclass of: Asymmetric Resource Consumption (Amplification)
cwe-id: CWE-1176

Use of Prohibited Code
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1177

Incorrect Access of Indexable Resource ('Range Error')
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-118

Insecure Default Initialization of Resource
type: Class
subclass of: Improper Initialization
cwe-id: CWE-1188

Improper Isolation of Shared Resources on System-on-a-Chip (SoC)
type: Class
subclass of: Improper Isolation or Compartmentalization
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-1189

Improper Restriction of Operations within the Bounds of a Memory Buffer
type: Class
subclass of: Incorrect Access of Indexable Resource ('Range Error')
subclass of: Restriction
  on property: weakness-of
  some values from: Raw Memory Access Function
type: NamedIndividual
weakness-of: Raw Memory Access Function
cwe-id: CWE-119

DMA Device Enabled Too Early in Boot Phase
type: Class
subclass of: Incorrect Behavior Order
cwe-id: CWE-1190

On-Chip Debug and Test Interface With Improper Access Control
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1191

System-on-Chip (SoC) Using Components without Unique, Immutable Identifiers
type: Class
subclass of: Violation of Secure Design Principles
cwe-id: CWE-1192

Power-On of Untrusted Execution Core Before Enabling Fabric Access Control
type: Class
subclass of: Incorrect Behavior Order
cwe-id: CWE-1193

ASP.NET Misconfiguration: Missing Custom Error Page
type: Class
subclass of: Missing Custom Error Page
cwe-id: CWE-12

Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
type: Class
subclass of: Improper Restriction of Operations within the Bounds of a Memory Buffer
cwe-id: CWE-120

Generation of Weak Initialization Vector (IV)
type: Class
subclass of: Use of Insufficiently Random Values
cwe-id: CWE-1204

Failure to Disable Reserved Bits
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1209

Stack-based Buffer Overflow
type: Class
subclass of: Out-of-bounds Write
subclass of: Access of Memory Location After End of Buffer
cwe-id: CWE-121

Heap-based Buffer Overflow
type: Class
subclass of: Out-of-bounds Write
subclass of: Access of Memory Location After End of Buffer
cwe-id: CWE-122

Insufficient Granularity of Access Control
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1220

Incorrect Register Defaults or Module Parameters
type: Class
subclass of: Improper Initialization
cwe-id: CWE-1221

Insufficient Granularity of Address Regions Protected by Register Locks
type: Class
subclass of: Insufficient Granularity of Access Control
cwe-id: CWE-1222

Race Condition for Write-Once Attributes
type: Class
subclass of: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
cwe-id: CWE-1223

Improper Restriction of Write-Once Bit Fields
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1224

Creation of Emergent Resource
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-1229

Write-what-where Condition
type: Class
subclass of: Out-of-bounds Write
cwe-id: CWE-123

Exposure of Sensitive Information Through Metadata
type: Class
subclass of: Improper Authorization
cwe-id: CWE-1230

Improper Prevention of Lock Bit Modification
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1231

Improper Lock Behavior After Power State Transition
type: Class
subclass of: Improper Locking
cwe-id: CWE-1232

Security-Sensitive Hardware Controls with Missing Lock Bit Protection
type: Class
subclass of: Improper Access Control
subclass of: Improper Locking
cwe-id: CWE-1233

Hardware Internal or Debug Modes Allow Override of Locks
type: Class
subclass of: Improper Locking
cwe-id: CWE-1234

Incorrect Use of Autoboxing and Unboxing for Performance Critical Operations
type: Class
subclass of: Uncontrolled Resource Consumption
cwe-id: CWE-1235

Improper Neutralization of Formula Elements in a CSV File
type: Class
subclass of: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
cwe-id: CWE-1236

Improper Zeroization of Hardware Register
type: Class
subclass of: Sensitive Information in Resource Not Removed Before Reuse
cwe-id: CWE-1239

Buffer Underwrite ('Buffer Underflow')
type: Class
subclass of: Access of Memory Location Before Start of Buffer
subclass of: Out-of-bounds Write
cwe-id: CWE-124

Use of a Cryptographic Primitive with a Risky Implementation
type: Class
subclass of: Use of a Broken or Risky Cryptographic Algorithm
cwe-id: CWE-1240

Use of Predictable Algorithm in Random Number Generator
type: Class
subclass of: Use of Insufficiently Random Values
cwe-id: CWE-1241

Inclusion of Undocumented Features or Chicken Bits
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1242

Sensitive Non-Volatile Information Not Protected During Debug
type: Class
subclass of: Improper Physical Access Control
cwe-id: CWE-1243

Internal Asset Exposed to Unsafe Debug Access Level or State
type: Class
subclass of: Incorrect Authorization
cwe-id: CWE-1244

Improper Finite State Machines (FSMs) in Hardware Logic
type: Class
subclass of: Incorrect Provision of Specified Functionality
cwe-id: CWE-1245

Improper Write Handling in Limited-write Non-Volatile Memories
type: Class
subclass of: Uncontrolled Resource Consumption
cwe-id: CWE-1246

Improper Protection Against Voltage and Clock Glitches
type: Class
subclass of: Improper Handling of Physical or Environmental Conditions
cwe-id: CWE-1247

Semiconductor Defects in Hardware Logic with Security-Sensitive Implications
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-1248

Application-Level Admin Tool with Inconsistent View of Underlying Operating System
type: Class
subclass of: Improper Preservation of Consistency Between Independent Representations of Shared State
cwe-id: CWE-1249

Out-of-bounds Read
type: Class
subclass of: Improper Restriction of Operations within the Bounds of a Memory Buffer
subclass of: Restriction
  on property: weakness-of
  some values from: Raw Memory Access Function
type: NamedIndividual
weakness-of: Raw Memory Access Function
cwe-id: CWE-125

Improper Preservation of Consistency Between Independent Representations of Shared State
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-1250

Mirrored Regions with Different Values
type: Class
subclass of: Improper Preservation of Consistency Between Independent Representations of Shared State
cwe-id: CWE-1251

CPU Hardware Not Configured to Support Exclusivity of Write and Execute Operations
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1252

Incorrect Selection of Fuse Values
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-1253

Incorrect Comparison Logic Granularity
type: Class
subclass of: Observable Timing Discrepancy
subclass of: Incorrect Comparison
cwe-id: CWE-1254

Comparison Logic is Vulnerable to Power Side-Channel Attacks
type: Class
subclass of: Improper Protection of Physical Side Channels
cwe-id: CWE-1255

Improper Restriction of Software Interfaces to Hardware Features
type: Class
subclass of: Improper Authorization
cwe-id: CWE-1256

Improper Access Control Applied to Mirrored or Aliased Memory Regions
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1257

Exposure of Sensitive System Information Due to Uncleared Debug Information
type: Class
subclass of: Exposure of Sensitive Information to an Unauthorized Actor
subclass of: Improper Removal of Sensitive Information Before Storage or Transfer
cwe-id: CWE-1258

Improper Restriction of Security Token Assignment
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1259

Buffer Over-read
type: Class
subclass of: Out-of-bounds Read
subclass of: Access of Memory Location After End of Buffer
cwe-id: CWE-126

Improper Handling of Overlap Between Protected Memory Ranges
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1260

Improper Handling of Single Event Upsets
type: Class
subclass of: Improper Handling of Physical or Environmental Conditions
cwe-id: CWE-1261

Improper Access Control for Register Interface
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1262

Improper Physical Access Control
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1263

Hardware Logic with Insecure De-Synchronization between Control and Data Channels
type: Class
subclass of: Incorrect Synchronization
cwe-id: CWE-1264

Unintended Reentrant Invocation of Non-reentrant Code Via Nested Calls
type: Class
subclass of: Insufficient Control Flow Management
cwe-id: CWE-1265

Improper Scrubbing of Sensitive Data from Decommissioned Device
type: Class
subclass of: Improper Resource Shutdown or Release
cwe-id: CWE-1266

Policy Uses Obsolete Encoding
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1267

Policy Privileges are not Assigned Consistently Between Control and Data Agents
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1268

Product Released in Non-Release Configuration
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-1269

Buffer Under-read
type: Class
subclass of: Out-of-bounds Read
subclass of: Access of Memory Location Before Start of Buffer
cwe-id: CWE-127

Generation of Incorrect Security Tokens
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1270

Uninitialized Value on Reset for Registers Holding Security Settings
type: Class
subclass of: Missing Initialization of Resource
cwe-id: CWE-1271

Sensitive Information Uncleared Before Debug/Power State Transition
type: Class
subclass of: Sensitive Information in Resource Not Removed Before Reuse
cwe-id: CWE-1272

Device Unlock Credential Sharing
type: Class
subclass of: Exposure of Sensitive Information to an Unauthorized Actor
cwe-id: CWE-1273

Improper Access Control for Volatile Memory Containing Boot Code
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1274

Sensitive Cookie with Improper SameSite Attribute
type: Class
subclass of: Improper Restriction of Communication Channel to Intended Endpoints
cwe-id: CWE-1275

Hardware Child Block Incorrectly Connected to Parent System
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1276

Firmware Not Updateable
type: Class
subclass of: Reliance on Component That is Not Updateable
cwe-id: CWE-1277

Missing Protection Against Hardware Reverse Engineering Using Integrated Circuit (IC) Imaging Techniques
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-1278

Cryptographic Operations are run Before Supporting Units are Ready
type: Class
subclass of: Improper Initialization
cwe-id: CWE-1279

Wrap-around Error
type: Class
subclass of: Incorrect Calculation
cwe-id: CWE-128

Access Control Check Implemented After Asset is Accessed
type: Class
subclass of: Improper Access Control
subclass of: Incorrect Behavior Order
cwe-id: CWE-1280

Sequence of Processor Instructions Leads to Unexpected Behavior
type: Class
subclass of: Insufficient Control Flow Management
cwe-id: CWE-1281

Assumed-Immutable Data is Stored in Writable Memory
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-1282

Mutable Attestation or Measurement Reporting Data
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1283

Improper Validation of Specified Quantity in Input
type: Class
subclass of: Improper Input Validation
cwe-id: CWE-1284

Improper Validation of Specified Index, Position, or Offset in Input
type: Class
subclass of: Improper Input Validation
cwe-id: CWE-1285

Improper Validation of Syntactic Correctness of Input
type: Class
subclass of: Improper Input Validation
cwe-id: CWE-1286

Improper Validation of Specified Type of Input
type: Class
subclass of: Improper Input Validation
cwe-id: CWE-1287

Improper Validation of Consistency within Input
type: Class
subclass of: Improper Input Validation
cwe-id: CWE-1288

Improper Validation of Unsafe Equivalence in Input
type: Class
subclass of: Improper Input Validation
cwe-id: CWE-1289

Improper Validation of Array Index
type: Class
subclass of: Improper Validation of Specified Index, Position, or Offset in Input
cwe-id: CWE-129

Incorrect Decoding of Security Identifiers
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1290

Public Key Re-Use for Signing both Debug and Production Code
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-1291

Incorrect Conversion of Security Identifiers
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1292

Missing Source Correlation of Multiple Independent Data
type: Class
subclass of: Insufficient Verification of Data Authenticity
cwe-id: CWE-1293

Insecure Security Identifier Mechanism
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1294

Debug Messages Revealing Unnecessary Information
type: Class
subclass of: Exposure of Sensitive Information to an Unauthorized Actor
cwe-id: CWE-1295

Incorrect Chaining or Granularity of Debug Components
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1296

Unprotected Confidential Information on Device is Accessible by OSAT Vendors
type: Class
subclass of: Improper Authorization
cwe-id: CWE-1297

Hardware Logic Contains Race Conditions
type: Class
subclass of: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
cwe-id: CWE-1298

Missing Protection Mechanism for Alternate Hardware Interface
type: Class
subclass of: Authentication Bypass Using an Alternate Path or Channel
subclass of: Unprotected Alternate Channel
cwe-id: CWE-1299

ASP.NET Misconfiguration: Password in Configuration File
type: Class
subclass of: Password in Configuration File
cwe-id: CWE-13

Improper Handling of Length Parameter Inconsistency
type: Class
subclass of: Improper Handling of Inconsistent Structural Elements
cwe-id: CWE-130

Improper Protection of Physical Side Channels
type: Class
subclass of: Observable Discrepancy
cwe-id: CWE-1300

Insufficient or Incomplete Data Removal within Hardware Component
type: Class
subclass of: Sensitive Information in Resource Not Removed Before Reuse
cwe-id: CWE-1301

Missing Security Identifier
type: Class
subclass of: Insecure Security Identifier Mechanism
cwe-id: CWE-1302

Non-Transparent Sharing of Microarchitectural Resources
type: Class
subclass of: Improper Isolation of Shared Resources on System-on-a-Chip (SoC)
subclass of: Observable Discrepancy
cwe-id: CWE-1303

Improperly Preserved Integrity of Hardware Configuration State During a Power Save/Restore Operation
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1304

Incorrect Calculation of Buffer Size
type: Class
subclass of: Incorrect Calculation
cwe-id: CWE-131

Missing Ability to Patch ROM Code
type: Class
subclass of: Reliance on Component That is Not Updateable
cwe-id: CWE-1310

Improper Translation of Security Attributes by Fabric Bridge
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1311

Missing Protection for Mirrored Regions in On-Chip Fabric Firewall
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1312

Hardware Allows Activation of Test or Debug Logic at Runtime
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1313

Missing Write Protection for Parametric Data Values
type: Class
subclass of: Missing Authorization
cwe-id: CWE-1314

Improper Setting of Bus Controlling Capability in Fabric End-point
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1315

Fabric-Address Map Allows Programming of Unwarranted Overlaps of Protected and Unprotected Ranges
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1316

Improper Access Control in Fabric Bridge
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1317

Missing Support for Security Features in On-chip Fabrics or Buses
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-1318

Improper Protection against Electromagnetic Fault Injection (EM-FI)
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-1319

Improper Protection for Outbound Error Messages and Alert Signals
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1320

Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
type: Class
subclass of: Improperly Controlled Modification of Dynamically-Determined Object Attributes
cwe-id: CWE-1321

Use of Blocking Code in Single-threaded, Non-blocking Context
type: Class
subclass of: Excessive Iteration
cwe-id: CWE-1322

Improper Management of Sensitive Trace Data
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1323

Improperly Controlled Sequential Memory Allocation
type: Class
subclass of: Allocation of Resources Without Limits or Throttling
cwe-id: CWE-1325

Missing Immutable Root of Trust in Hardware
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-1326

Binding to an Unrestricted IP Address
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-1327

Security Version Number Mutable to Older Versions
type: Class
subclass of: Improper Authorization
cwe-id: CWE-1328

Reliance on Component That is Not Updateable
type: Class
subclass of: Reliance on Insufficiently Trustworthy Component
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-1329

Remanent Data Readable after Memory Erase
type: Class
subclass of: Insufficient or Incomplete Data Removal within Hardware Component
cwe-id: CWE-1330

Improper Isolation of Shared Resources in Network On Chip (NoC)
type: Class
subclass of: Improper Isolation or Compartmentalization
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-1331

Improper Handling of Faults that Lead to Instruction Skips
type: Class
subclass of: Improper Handling of Physical or Environmental Conditions
cwe-id: CWE-1332

Inefficient Regular Expression Complexity
type: Class
subclass of: Inefficient Algorithmic Complexity
cwe-id: CWE-1333

Unauthorized Error Injection Can Degrade Hardware Redundancy
type: Class
subclass of: Improper Access Control
cwe-id: CWE-1334

Incorrect Bitwise Shift of Integer
type: Class
subclass of: Incorrect Calculation
cwe-id: CWE-1335

Improper Neutralization of Special Elements Used in a Template Engine
type: Class
subclass of: Improper Control of Generation of Code ('Code Injection')
cwe-id: CWE-1336

Improper Protections Against Hardware Overheating
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-1338

Insufficient Precision or Accuracy of a Real Number
type: Class
subclass of: Incorrect Calculation
cwe-id: CWE-1339

Use of Externally-Controlled Format String
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-134

Multiple Releases of Same Resource or Handle
type: Class
subclass of: Multiple Operations on Resource in Single-Operation Context
cwe-id: CWE-1341

Information Exposure through Microarchitectural State after Transient Execution
type: Class
subclass of: Sensitive Information in Resource Not Removed Before Reuse
cwe-id: CWE-1342

Incorrect Calculation of Multi-Byte String Length
type: Class
subclass of: Incorrect Calculation
cwe-id: CWE-135

Improper Handling of Hardware Behavior in Exceptionally Cold Environments
type: Class
subclass of: Improper Handling of Physical or Environmental Conditions
cwe-id: CWE-1351

Reliance on Insufficiently Trustworthy Component
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-1357

Improper Neutralization of Special Elements
type: Class
subclass of: Improper Neutralization
cwe-id: CWE-138

Improper Handling of Physical or Environmental Conditions
type: Class
subclass of: Improper Check or Handling of Exceptional Conditions
cwe-id: CWE-1384

Missing Origin Validation in WebSockets
type: Class
subclass of: Origin Validation Error
cwe-id: CWE-1385

Insecure Operation on Windows Junction / Mount Point
type: Class
subclass of: Improper Link Resolution Before File Access ('Link Following')
cwe-id: CWE-1386

Incorrect Parsing of Numbers with Different Radices
type: Class
subclass of: Incorrect Type Conversion or Cast
cwe-id: CWE-1389

Weak Authentication
type: Class
subclass of: Improper Authentication
cwe-id: CWE-1390

Use of Weak Credentials
type: Class
subclass of: Weak Authentication
cwe-id: CWE-1391

Use of Default Credentials
type: Class
subclass of: Use of Weak Credentials
cwe-id: CWE-1392

Use of Default Password
type: Class
subclass of: Use of Default Credentials
cwe-id: CWE-1393

Use of Default Cryptographic Key
type: Class
subclass of: Use of Default Credentials
cwe-id: CWE-1394

Dependency on Vulnerable Third-Party Component
type: Class
subclass of: Violation of Secure Design Principles
cwe-id: CWE-1395

Compiler Removal of Code to Clear Buffers
type: Class
subclass of: Compiler Optimization Removal or Modification of Security-critical Code
cwe-id: CWE-14

Improper Neutralization of Delimiters
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-140

Improper Neutralization of Parameter/Argument Delimiters
type: Class
subclass of: Improper Neutralization of Delimiters
cwe-id: CWE-141

Improper Neutralization of Value Delimiters
type: Class
subclass of: Improper Neutralization of Delimiters
cwe-id: CWE-142

Improper Neutralization of Record Delimiters
type: Class
subclass of: Improper Neutralization of Delimiters
cwe-id: CWE-143

Improper Neutralization of Line Delimiters
type: Class
subclass of: Improper Neutralization of Delimiters
cwe-id: CWE-144

Improper Neutralization of Section Delimiters
type: Class
subclass of: Improper Neutralization of Delimiters
cwe-id: CWE-145

Improper Neutralization of Expression/Command Delimiters
type: Class
subclass of: Improper Neutralization of Delimiters
cwe-id: CWE-146

Improper Neutralization of Input Terminators
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-147

Improper Neutralization of Input Leaders
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-148

Improper Neutralization of Quoting Syntax
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-149

External Control of System or Configuration Setting
type: Class
subclass of: Externally Controlled Reference to a Resource in Another Sphere
subclass of: External Control of Critical State Data
cwe-id: CWE-15

Improper Neutralization of Escape, Meta, or Control Sequences
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-150

Improper Neutralization of Comment Delimiters
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-151

Improper Neutralization of Macro Symbols
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-152

Improper Neutralization of Substitution Characters
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-153

Improper Neutralization of Variable Name Delimiters
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-154

Improper Neutralization of Wildcards or Matching Symbols
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-155

Improper Neutralization of Whitespace
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-156

Failure to Sanitize Paired Delimiters
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-157

Improper Neutralization of Null Byte or NUL Character
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-158

Improper Handling of Invalid Use of Special Elements
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-159

Improper Neutralization of Leading Special Elements
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-160

Improper Neutralization of Multiple Leading Special Elements
type: Class
subclass of: Improper Neutralization of Leading Special Elements
cwe-id: CWE-161

Improper Neutralization of Trailing Special Elements
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-162

Improper Neutralization of Multiple Trailing Special Elements
type: Class
subclass of: Improper Neutralization of Trailing Special Elements
cwe-id: CWE-163

Improper Neutralization of Internal Special Elements
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-164

Improper Neutralization of Multiple Internal Special Elements
type: Class
subclass of: Improper Neutralization of Internal Special Elements
cwe-id: CWE-165

Improper Handling of Missing Special Element
type: Class
subclass of: Improper Handling of Invalid Use of Special Elements
subclass of: Improper Check or Handling of Exceptional Conditions
cwe-id: CWE-166

Improper Handling of Additional Special Element
type: Class
subclass of: Improper Handling of Invalid Use of Special Elements
subclass of: Improper Check or Handling of Exceptional Conditions
cwe-id: CWE-167

Improper Handling of Inconsistent Special Elements
type: Class
subclass of: Improper Handling of Invalid Use of Special Elements
subclass of: Improper Check or Handling of Exceptional Conditions
cwe-id: CWE-168

Improper Null Termination
type: Class
subclass of: Improper Neutralization
cwe-id: CWE-170

Encoding Error
type: Class
subclass of: Improper Neutralization
cwe-id: CWE-172

Improper Handling of Alternate Encoding
type: Class
subclass of: Encoding Error
cwe-id: CWE-173

Double Decoding of the Same Data
type: Class
subclass of: Encoding Error
subclass of: Multiple Operations on Resource in Single-Operation Context
cwe-id: CWE-174

Improper Handling of Mixed Encoding
type: Class
subclass of: Encoding Error
cwe-id: CWE-175

Improper Handling of Unicode Encoding
type: Class
subclass of: Encoding Error
cwe-id: CWE-176

Improper Handling of URL Encoding (Hex Encoding)
type: Class
subclass of: Encoding Error
cwe-id: CWE-177

Improper Handling of Case Sensitivity
type: Class
subclass of: Use of Incorrectly-Resolved Name or Reference
cwe-id: CWE-178

Incorrect Behavior Order: Early Validation
type: Class
subclass of: Improper Input Validation
subclass of: Incorrect Behavior Order
cwe-id: CWE-179

Incorrect Behavior Order: Validate Before Canonicalize
type: Class
subclass of: Incorrect Behavior Order: Early Validation
cwe-id: CWE-180

Incorrect Behavior Order: Validate Before Filter
type: Class
subclass of: Incorrect Behavior Order: Early Validation
cwe-id: CWE-181

Collapse of Data into Unsafe Value
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-182

Permissive List of Allowed Inputs
type: Class
subclass of: Incorrect Comparison
cwe-id: CWE-183

Incomplete List of Disallowed Inputs
type: Class
subclass of: Incomplete Comparison with Missing Factors
subclass of: Protection Mechanism Failure
cwe-id: CWE-184

Incorrect Regular Expression
type: Class
subclass of: Incorrect Comparison
cwe-id: CWE-185

Overly Restrictive Regular Expression
type: Class
subclass of: Incorrect Regular Expression
cwe-id: CWE-186

Partial String Comparison
type: Class
subclass of: Incomplete Comparison with Missing Factors
cwe-id: CWE-187

Reliance on Data/Memory Layout
type: Class
subclass of: Insufficient Encapsulation of Machine-Dependent Functionality
subclass of: Improper Interaction Between Multiple Correctly-Behaving Entities
cwe-id: CWE-188

Integer Overflow or Wraparound
type: Class
subclass of: Incorrect Calculation
subclass of: Restriction
  on property: weakness-of
  some values from: Mathematical Function
type: NamedIndividual
weakness-of: Mathematical Function
cwe-id: CWE-190

Integer Underflow (Wrap or Wraparound)
type: Class
subclass of: Incorrect Calculation
cwe-id: CWE-191

Integer Coercion Error
type: Class
subclass of: Incorrect Conversion between Numeric Types
cwe-id: CWE-192

Off-by-one Error
type: Class
subclass of: Incorrect Calculation
cwe-id: CWE-193

Unexpected Sign Extension
type: Class
subclass of: Incorrect Conversion between Numeric Types
cwe-id: CWE-194

Signed to Unsigned Conversion Error
type: Class
subclass of: Incorrect Conversion between Numeric Types
cwe-id: CWE-195

Unsigned to Signed Conversion Error
type: Class
subclass of: Incorrect Conversion between Numeric Types
cwe-id: CWE-196

Numeric Truncation Error
type: Class
subclass of: Incorrect Conversion between Numeric Types
cwe-id: CWE-197

Use of Incorrect Byte Ordering
type: Class
subclass of: Reliance on Data/Memory Layout
cwe-id: CWE-198

Improper Input Validation
type: Class
subclass of: Improper Neutralization
subclass of: Restriction
  on property: weakness-of
  some values from: User Input Function
type: NamedIndividual
weakness-of: User Input Function
cwe-id: CWE-20

Exposure of Sensitive Information to an Unauthorized Actor
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-200

Insertion of Sensitive Information Into Sent Data
type: Class
subclass of: Exposure of Sensitive Information to an Unauthorized Actor
cwe-id: CWE-201

Exposure of Sensitive Information Through Data Queries
type: Class
subclass of: Exposure of Sensitive Information Through Metadata
cwe-id: CWE-202

Observable Discrepancy
type: Class
subclass of: Exposure of Sensitive Information to an Unauthorized Actor
cwe-id: CWE-203

Observable Response Discrepancy
type: Class
subclass of: Observable Discrepancy
cwe-id: CWE-204

Observable Behavioral Discrepancy
type: Class
subclass of: Observable Discrepancy
cwe-id: CWE-205

Observable Internal Behavioral Discrepancy
type: Class
subclass of: Observable Behavioral Discrepancy
cwe-id: CWE-206

Observable Behavioral Discrepancy With Equivalent Products
type: Class
subclass of: Observable Behavioral Discrepancy
cwe-id: CWE-207

Observable Timing Discrepancy
type: Class
subclass of: Observable Discrepancy
cwe-id: CWE-208

Generation of Error Message Containing Sensitive Information
type: Class
subclass of: Exposure of Sensitive Information to an Unauthorized Actor
subclass of: Improper Handling of Exceptional Conditions
cwe-id: CWE-209

Self-generated Error Message Containing Sensitive Information
type: Class
subclass of: Generation of Error Message Containing Sensitive Information
cwe-id: CWE-210

Externally-Generated Error Message Containing Sensitive Information
type: Class
subclass of: Generation of Error Message Containing Sensitive Information
cwe-id: CWE-211

Improper Removal of Sensitive Information Before Storage or Transfer
type: Class
subclass of: Incorrect Resource Transfer Between Spheres
cwe-id: CWE-212

Exposure of Sensitive Information Due to Incompatible Policies
type: Class
subclass of: Exposure of Sensitive Information to an Unauthorized Actor
cwe-id: CWE-213

Invocation of Process Using Visible Sensitive Information
type: Class
subclass of: Exposure of Sensitive System Information to an Unauthorized Control Sphere
cwe-id: CWE-214

Insertion of Sensitive Information Into Debugging Code
type: Class
subclass of: Exposure of Sensitive Information to an Unauthorized Actor
cwe-id: CWE-215

Storage of File with Sensitive Data Under Web Root
type: Class
subclass of: Files or Directories Accessible to External Parties
cwe-id: CWE-219

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
type: Class
subclass of: Exposure of Resource to Wrong Sphere
subclass of: Use of Incorrectly-Resolved Name or Reference
subclass of: Restriction
  on property: weakness-of
  some values from: User Input Function
type: NamedIndividual
weakness-of: User Input Function
cwe-id: CWE-22

Storage of File With Sensitive Data Under FTP Root
type: Class
subclass of: Files or Directories Accessible to External Parties
cwe-id: CWE-220

Information Loss or Omission
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-221

Truncation of Security-relevant Information
type: Class
subclass of: Information Loss or Omission
cwe-id: CWE-222

Omission of Security-relevant Information
type: Class
subclass of: Information Loss or Omission
cwe-id: CWE-223

Obscured Security-relevant Information by Alternate Name
type: Class
subclass of: Information Loss or Omission
cwe-id: CWE-224

Sensitive Information in Resource Not Removed Before Reuse
type: Class
subclass of: Improper Removal of Sensitive Information Before Storage or Transfer
subclass of: Incomplete Cleanup
cwe-id: CWE-226

Improper Handling of Syntactically Invalid Structure
type: Class
subclass of: Improper Check or Handling of Exceptional Conditions
subclass of: Improper Neutralization
cwe-id: CWE-228

Improper Handling of Values
type: Class
subclass of: Improper Handling of Syntactically Invalid Structure
cwe-id: CWE-229

Relative Path Traversal
type: Class
subclass of: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
cwe-id: CWE-23

Improper Handling of Missing Values
type: Class
subclass of: Improper Handling of Values
cwe-id: CWE-230

Improper Handling of Extra Values
type: Class
subclass of: Improper Handling of Values
cwe-id: CWE-231

Improper Handling of Undefined Values
type: Class
subclass of: Improper Handling of Values
cwe-id: CWE-232

Improper Handling of Parameters
type: Class
subclass of: Improper Handling of Syntactically Invalid Structure
cwe-id: CWE-233

Failure to Handle Missing Parameter
type: Class
subclass of: Improper Handling of Parameters
cwe-id: CWE-234

Improper Handling of Extra Parameters
type: Class
subclass of: Improper Handling of Parameters
cwe-id: CWE-235

Improper Handling of Undefined Parameters
type: Class
subclass of: Improper Handling of Parameters
cwe-id: CWE-236

Improper Handling of Structural Elements
type: Class
subclass of: Improper Handling of Syntactically Invalid Structure
cwe-id: CWE-237

Improper Handling of Incomplete Structural Elements
type: Class
subclass of: Improper Handling of Structural Elements
cwe-id: CWE-238

Failure to Handle Incomplete Element
type: Class
subclass of: Improper Handling of Structural Elements
cwe-id: CWE-239

Path Traversal: '../filedir'
type: Class
subclass of: Relative Path Traversal
cwe-id: CWE-24

Improper Handling of Inconsistent Structural Elements
type: Class
subclass of: Improper Handling of Structural Elements
subclass of: Improper Neutralization
cwe-id: CWE-240

Improper Handling of Unexpected Data Type
type: Class
subclass of: Improper Handling of Syntactically Invalid Structure
cwe-id: CWE-241

Use of Inherently Dangerous Function
type: Class
subclass of: Use of Prohibited Code
cwe-id: CWE-242

Creation of chroot Jail Without Changing Working Directory
type: Class
subclass of: Improper Following of Specification by Caller
subclass of: Incorrect Resource Transfer Between Spheres
cwe-id: CWE-243

Improper Clearing of Heap Memory Before Release ('Heap Inspection')
type: Class
subclass of: Sensitive Information in Resource Not Removed Before Reuse
cwe-id: CWE-244

J2EE Bad Practices: Direct Management of Connections
type: Class
subclass of: Use of Low-Level Functionality
cwe-id: CWE-245

J2EE Bad Practices: Direct Use of Sockets
type: Class
subclass of: Use of Low-Level Functionality
cwe-id: CWE-246

Uncaught Exception
type: Class
subclass of: Improper Check or Handling of Exceptional Conditions
subclass of: Incorrect Control Flow Scoping
cwe-id: CWE-248

Path Traversal: '/../filedir'
type: Class
subclass of: Relative Path Traversal
cwe-id: CWE-25

Execution with Unnecessary Privileges
type: Class
subclass of: Improper Privilege Management
subclass of: Violation of Secure Design Principles
cwe-id: CWE-250

Unchecked Return Value
type: Class
subclass of: Improper Check for Unusual or Exceptional Conditions
cwe-id: CWE-252

Incorrect Check of Function Return Value
type: Class
subclass of: Improper Following of Specification by Caller
subclass of: Improper Check for Unusual or Exceptional Conditions
cwe-id: CWE-253

Plaintext Storage of a Password
type: Class
subclass of: Insufficiently Protected Credentials
cwe-id: CWE-256

Storing Passwords in a Recoverable Format
type: Class
subclass of: Insufficiently Protected Credentials
cwe-id: CWE-257

Empty Password in Configuration File
type: Class
subclass of: Password in Configuration File
subclass of: Weak Password Requirements
cwe-id: CWE-258

Use of Hard-coded Password
type: Class
subclass of: Use of Hard-coded Credentials
cwe-id: CWE-259

Path Traversal: '/dir/../filename'
type: Class
subclass of: Relative Path Traversal
cwe-id: CWE-26

Password in Configuration File
type: Class
subclass of: Insufficiently Protected Credentials
cwe-id: CWE-260

Weak Encoding for Password
type: Class
subclass of: Insufficiently Protected Credentials
cwe-id: CWE-261

Not Using Password Aging
type: Class
subclass of: Weak Authentication
cwe-id: CWE-262

Password Aging with Long Expiration
type: Class
subclass of: Weak Authentication
cwe-id: CWE-263

Incorrect Privilege Assignment
type: Class
subclass of: Improper Privilege Management
cwe-id: CWE-266

Privilege Defined With Unsafe Actions
type: Class
subclass of: Improper Privilege Management
cwe-id: CWE-267

Privilege Chaining
type: Class
subclass of: Improper Privilege Management
cwe-id: CWE-268

Improper Privilege Management
type: Class
subclass of: Improper Access Control
cwe-id: CWE-269

Path Traversal: 'dir/../../filename'
type: Class
subclass of: Relative Path Traversal
cwe-id: CWE-27

Privilege Context Switching Error
type: Class
subclass of: Improper Privilege Management
cwe-id: CWE-270

Privilege Dropping / Lowering Errors
type: Class
subclass of: Improper Privilege Management
cwe-id: CWE-271

Least Privilege Violation
type: Class
subclass of: Privilege Dropping / Lowering Errors
cwe-id: CWE-272

Improper Check for Dropped Privileges
type: Class
subclass of: Privilege Dropping / Lowering Errors
subclass of: Improper Check for Unusual or Exceptional Conditions
cwe-id: CWE-273

Improper Handling of Insufficient Privileges
type: Class
subclass of: Improper Privilege Management
subclass of: Improper Handling of Exceptional Conditions
cwe-id: CWE-274

Incorrect Default Permissions
type: Class
subclass of: Incorrect Permission Assignment for Critical Resource
subclass of: Restriction
  on property: weakness-of
  some values from: Application Installer
type: NamedIndividual
weakness-of: Application Installer
cwe-id: CWE-276

Insecure Inherited Permissions
type: Class
subclass of: Incorrect Permission Assignment for Critical Resource
cwe-id: CWE-277

Insecure Preserved Inherited Permissions
type: Class
subclass of: Incorrect Permission Assignment for Critical Resource
cwe-id: CWE-278

Incorrect Execution-Assigned Permissions
type: Class
subclass of: Incorrect Permission Assignment for Critical Resource
cwe-id: CWE-279

Path Traversal: '..\filedir'
type: Class
subclass of: Relative Path Traversal
cwe-id: CWE-28

Improper Handling of Insufficient Permissions or Privileges
type: Class
subclass of: Improper Handling of Exceptional Conditions
cwe-id: CWE-280

Improper Preservation of Permissions
type: Class
subclass of: Incorrect Permission Assignment for Critical Resource
cwe-id: CWE-281

Improper Ownership Management
type: Class
subclass of: Improper Access Control
cwe-id: CWE-282

Unverified Ownership
type: Class
subclass of: Improper Ownership Management
cwe-id: CWE-283

Improper Access Control
type: Class
subclass of: Weakness
cwe-id: CWE-284

Improper Authorization
type: Class
subclass of: Improper Access Control
cwe-id: CWE-285

Incorrect User Management
type: Class
subclass of: Improper Access Control
cwe-id: CWE-286

Improper Authentication
type: Class
subclass of: Improper Access Control
subclass of: Restriction
  on property: weakness-of
  some values from: Authentication Function
type: NamedIndividual
weakness-of: Authentication Function
cwe-id: CWE-287

Authentication Bypass Using an Alternate Path or Channel
type: Class
subclass of: Missing Authentication for Critical Function
cwe-id: CWE-288

Authentication Bypass by Alternate Name
type: Class
subclass of: Weak Authentication
cwe-id: CWE-289

Path Traversal: '\..\filename'
type: Class
subclass of: Relative Path Traversal
cwe-id: CWE-29

Authentication Bypass by Spoofing
type: Class
subclass of: Weak Authentication
cwe-id: CWE-290

Reliance on IP Address for Authentication
type: Class
subclass of: Authentication Bypass by Spoofing
subclass of: Modification of Assumed-Immutable Data (MAID)
subclass of: Improper Restriction of Communication Channel to Intended Endpoints
cwe-id: CWE-291

Using Referer Field for Authentication
type: Class
subclass of: Authentication Bypass by Spoofing
cwe-id: CWE-293

Authentication Bypass by Capture-replay
type: Class
subclass of: Weak Authentication
cwe-id: CWE-294

Improper Certificate Validation
type: Class
subclass of: Improper Authentication
cwe-id: CWE-295

Improper Following of a Certificate's Chain of Trust
type: Class
subclass of: Improper Certificate Validation
subclass of: Improper Following of Specification by Caller
cwe-id: CWE-296

Improper Validation of Certificate with Host Mismatch
type: Class
subclass of: Improper Certificate Validation
subclass of: Improper Restriction of Communication Channel to Intended Endpoints
cwe-id: CWE-297

Improper Validation of Certificate Expiration
type: Class
subclass of: Improper Certificate Validation
subclass of: Operation on a Resource after Expiration or Release
cwe-id: CWE-298

Improper Check for Certificate Revocation
type: Class
subclass of: Improper Certificate Validation
subclass of: Improper Resource Shutdown or Release
cwe-id: CWE-299

Path Traversal: '\dir\..\filename'
type: Class
subclass of: Relative Path Traversal
cwe-id: CWE-30

Channel Accessible by Non-Endpoint
type: Class
subclass of: Improper Restriction of Communication Channel to Intended Endpoints
cwe-id: CWE-300

Reflection Attack in an Authentication Protocol
type: Class
subclass of: Weak Authentication
cwe-id: CWE-301

Authentication Bypass by Assumed-Immutable Data
type: Class
subclass of: Weak Authentication
subclass of: Reliance on Untrusted Inputs in a Security Decision
cwe-id: CWE-302

Incorrect Implementation of Authentication Algorithm
type: Class
subclass of: Weak Authentication
cwe-id: CWE-303

Missing Critical Step in Authentication
type: Class
subclass of: Incorrect Implementation of Authentication Algorithm
subclass of: Improper Following of Specification by Caller
cwe-id: CWE-304

Authentication Bypass by Primary Weakness
type: Class
subclass of: Weak Authentication
cwe-id: CWE-305

Missing Authentication for Critical Function
type: Class
subclass of: Improper Authentication
cwe-id: CWE-306

Improper Restriction of Excessive Authentication Attempts
type: Class
subclass of: Weak Authentication
subclass of: Improper Control of Interaction Frequency
cwe-id: CWE-307

Use of Single-factor Authentication
type: Class
subclass of: Weak Authentication
subclass of: Reliance on a Single Factor in a Security Decision
cwe-id: CWE-308

Use of Password System for Primary Authentication
type: Class
subclass of: Weak Authentication
subclass of: Reliance on a Single Factor in a Security Decision
cwe-id: CWE-309

Path Traversal: 'dir\..\..\filename'
type: Class
subclass of: Relative Path Traversal
cwe-id: CWE-31

Missing Encryption of Sensitive Data
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-311

Cleartext Storage of Sensitive Information
type: Class
subclass of: Missing Encryption of Sensitive Data
subclass of: Insecure Storage of Sensitive Information
cwe-id: CWE-312

Cleartext Storage in a File or on Disk
type: Class
subclass of: Cleartext Storage of Sensitive Information
cwe-id: CWE-313

Cleartext Storage in the Registry
type: Class
subclass of: Cleartext Storage of Sensitive Information
cwe-id: CWE-314

Cleartext Storage of Sensitive Information in a Cookie
type: Class
subclass of: Cleartext Storage of Sensitive Information
cwe-id: CWE-315

Cleartext Storage of Sensitive Information in Memory
type: Class
subclass of: Cleartext Storage of Sensitive Information
cwe-id: CWE-316

Cleartext Storage of Sensitive Information in GUI
type: Class
subclass of: Cleartext Storage of Sensitive Information
cwe-id: CWE-317

Cleartext Storage of Sensitive Information in Executable
type: Class
subclass of: Cleartext Storage of Sensitive Information
cwe-id: CWE-318

Cleartext Transmission of Sensitive Information
type: Class
subclass of: Missing Encryption of Sensitive Data
cwe-id: CWE-319

Path Traversal: '...' (Triple Dot)
type: Class
subclass of: Relative Path Traversal
cwe-id: CWE-32

Use of Hard-coded Cryptographic Key
type: Class
subclass of: Use of Hard-coded Credentials
cwe-id: CWE-321

Key Exchange without Entity Authentication
type: Class
subclass of: Missing Authentication for Critical Function
cwe-id: CWE-322

Reusing a Nonce, Key Pair in Encryption
type: Class
subclass of: Use of Invariant Value in Dynamically Changing Context
cwe-id: CWE-323

Use of a Key Past its Expiration Date
type: Class
subclass of: Operation on a Resource after Expiration or Release
cwe-id: CWE-324

Missing Cryptographic Step
type: Class
subclass of: Improper Following of Specification by Caller
cwe-id: CWE-325

Inadequate Encryption Strength
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-326

Use of a Broken or Risky Cryptographic Algorithm
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-327

Use of Weak Hash
type: Class
subclass of: Inadequate Encryption Strength
subclass of: Use of a Broken or Risky Cryptographic Algorithm
cwe-id: CWE-328

Generation of Predictable IV with CBC Mode
type: Class
subclass of: Generation of Weak Initialization Vector (IV)
subclass of: Improper Following of Specification by Caller
cwe-id: CWE-329

Path Traversal: '....' (Multiple Dot)
type: Class
subclass of: Relative Path Traversal
cwe-id: CWE-33

Use of Insufficiently Random Values
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-330

Insufficient Entropy
type: Class
subclass of: Use of Insufficiently Random Values
cwe-id: CWE-331

Insufficient Entropy in PRNG
type: Class
subclass of: Insufficient Entropy
cwe-id: CWE-332

Improper Handling of Insufficient Entropy in TRNG
type: Class
subclass of: Insufficient Entropy
subclass of: Improper Check or Handling of Exceptional Conditions
cwe-id: CWE-333

Small Space of Random Values
type: Class
subclass of: Use of Insufficiently Random Values
cwe-id: CWE-334

Incorrect Usage of Seeds in Pseudo-Random Number Generator (PRNG)
type: Class
subclass of: Use of Insufficiently Random Values
cwe-id: CWE-335

Same Seed in Pseudo-Random Number Generator (PRNG)
type: Class
subclass of: Incorrect Usage of Seeds in Pseudo-Random Number Generator (PRNG)
cwe-id: CWE-336

Predictable Seed in Pseudo-Random Number Generator (PRNG)
type: Class
subclass of: Incorrect Usage of Seeds in Pseudo-Random Number Generator (PRNG)
cwe-id: CWE-337

Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
type: Class
subclass of: Use of Insufficiently Random Values
cwe-id: CWE-338

Small Seed Space in PRNG
type: Class
subclass of: Incorrect Usage of Seeds in Pseudo-Random Number Generator (PRNG)
cwe-id: CWE-339

Path Traversal: '....//'
type: Class
subclass of: Relative Path Traversal
cwe-id: CWE-34

Generation of Predictable Numbers or Identifiers
type: Class
subclass of: Use of Insufficiently Random Values
cwe-id: CWE-340

Predictable from Observable State
type: Class
subclass of: Generation of Predictable Numbers or Identifiers
cwe-id: CWE-341

Predictable Exact Value from Previous Values
type: Class
subclass of: Generation of Predictable Numbers or Identifiers
cwe-id: CWE-342

Predictable Value Range from Previous Values
type: Class
subclass of: Generation of Predictable Numbers or Identifiers
cwe-id: CWE-343

Use of Invariant Value in Dynamically Changing Context
type: Class
subclass of: Use of Insufficiently Random Values
cwe-id: CWE-344

Insufficient Verification of Data Authenticity
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-345

Origin Validation Error
type: Class
subclass of: Improper Access Control
subclass of: Insufficient Verification of Data Authenticity
cwe-id: CWE-346

Improper Verification of Cryptographic Signature
type: Class
subclass of: Insufficient Verification of Data Authenticity
cwe-id: CWE-347

Use of Less Trusted Source
type: Class
subclass of: Insufficient Verification of Data Authenticity
cwe-id: CWE-348

Acceptance of Extraneous Untrusted Data With Trusted Data
type: Class
subclass of: Insufficient Verification of Data Authenticity
cwe-id: CWE-349

Path Traversal: '.../...//'
type: Class
subclass of: Relative Path Traversal
cwe-id: CWE-35

Reliance on Reverse DNS Resolution for a Security-Critical Action
type: Class
subclass of: Authentication Bypass by Spoofing
subclass of: Reliance on Untrusted Inputs in a Security Decision
cwe-id: CWE-350

Insufficient Type Distinction
type: Class
subclass of: Insufficient Verification of Data Authenticity
cwe-id: CWE-351

Cross-Site Request Forgery (CSRF)
type: Class
subclass of: Insufficient Verification of Data Authenticity
subclass of: Restriction
  on property: weakness-of
  some values from: User Input Function
type: NamedIndividual
weakness-of: User Input Function
cwe-id: CWE-352

Missing Support for Integrity Check
type: Class
subclass of: Insufficient Verification of Data Authenticity
cwe-id: CWE-353

Improper Validation of Integrity Check Value
type: Class
subclass of: Insufficient Verification of Data Authenticity
subclass of: Improper Check for Unusual or Exceptional Conditions
cwe-id: CWE-354

Product UI does not Warn User of Unsafe Actions
type: Class
subclass of: Information Loss or Omission
cwe-id: CWE-356

Insufficient UI Warning of Dangerous Operations
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-357

Improperly Implemented Security Check for Standard
type: Class
subclass of: Improper Following of Specification by Caller
subclass of: Protection Mechanism Failure
cwe-id: CWE-358

Exposure of Private Personal Information to an Unauthorized Actor
type: Class
subclass of: Exposure of Sensitive Information to an Unauthorized Actor
cwe-id: CWE-359

Absolute Path Traversal
type: Class
subclass of: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
cwe-id: CWE-36

Trust of System Event Data
type: Class
subclass of: Insufficient Verification of Data Authenticity
cwe-id: CWE-360

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
type: Class
subclass of: Insufficient Control Flow Management
subclass of: Restriction
  on property: weakness-of
  some values from: Shared Resource Access Function
type: NamedIndividual
weakness-of: Shared Resource Access Function
cwe-id: CWE-362

Race Condition Enabling Link Following
type: Class
subclass of: Time-of-check Time-of-use (TOCTOU) Race Condition
cwe-id: CWE-363

Signal Handler Race Condition
type: Class
subclass of: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
cwe-id: CWE-364

Race Condition within a Thread
type: Class
subclass of: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
cwe-id: CWE-366

Time-of-check Time-of-use (TOCTOU) Race Condition
type: Class
subclass of: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
cwe-id: CWE-367

Context Switching Race Condition
type: Class
subclass of: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
cwe-id: CWE-368

Divide By Zero
type: Class
subclass of: Incorrect Calculation
cwe-id: CWE-369

Path Traversal: '/absolute/pathname/here'
type: Class
subclass of: Improper Neutralization of Leading Special Elements
subclass of: Absolute Path Traversal
cwe-id: CWE-37

Missing Check for Certificate Revocation after Initial Check
type: Class
subclass of: Improper Check for Certificate Revocation
cwe-id: CWE-370

Incomplete Internal State Distinction
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-372

Passing Mutable Objects to an Untrusted Method
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-374

Returning a Mutable Object to an Untrusted Caller
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-375

Insecure Temporary File
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-377

Creation of Temporary File With Insecure Permissions
type: Class
subclass of: Insecure Temporary File
cwe-id: CWE-378

Creation of Temporary File in Directory with Insecure Permissions
type: Class
subclass of: Insecure Temporary File
cwe-id: CWE-379

Path Traversal: '\absolute\pathname\here'
type: Class
subclass of: Absolute Path Traversal
cwe-id: CWE-38

J2EE Bad Practices: Use of System.exit()
type: Class
subclass of: Incorrect Control Flow Scoping
cwe-id: CWE-382

J2EE Bad Practices: Direct Use of Threads
type: Class
subclass of: Use of Low-Level Functionality
cwe-id: CWE-383

Session Fixation
type: Class
subclass of: Externally Controlled Reference to a Resource in Another Sphere
cwe-id: CWE-384

Covert Timing Channel
type: Class
subclass of: Covert Channel
cwe-id: CWE-385

Symbolic Name not Mapping to Correct Object
type: Class
subclass of: Use of Incorrectly-Resolved Name or Reference
cwe-id: CWE-386

Path Traversal: 'C:dirname'
type: Class
subclass of: Absolute Path Traversal
cwe-id: CWE-39

Detection of Error Condition Without Action
type: Class
subclass of: Improper Handling of Exceptional Conditions
cwe-id: CWE-390

Unchecked Error Condition
type: Class
subclass of: Improper Check for Unusual or Exceptional Conditions
cwe-id: CWE-391

Missing Report of Error Condition
type: Class
subclass of: Incorrect Provision of Specified Functionality
subclass of: Improper Check or Handling of Exceptional Conditions
cwe-id: CWE-392

Return of Wrong Status Code
type: Class
subclass of: Incorrect Provision of Specified Functionality
subclass of: Improper Check or Handling of Exceptional Conditions
cwe-id: CWE-393

Unexpected Status Code or Return Value
type: Class
subclass of: Improper Check for Unusual or Exceptional Conditions
cwe-id: CWE-394

Use of NullPointerException Catch to Detect NULL Pointer Dereference
type: Class
subclass of: Incorrect Control Flow Scoping
subclass of: Improper Handling of Exceptional Conditions
cwe-id: CWE-395

Declaration of Catch for Generic Exception
type: Class
subclass of: Information Loss or Omission
subclass of: Incorrect Control Flow Scoping
subclass of: Improper Handling of Exceptional Conditions
cwe-id: CWE-396

Declaration of Throws for Generic Exception
type: Class
subclass of: Information Loss or Omission
subclass of: Improper Check or Handling of Exceptional Conditions
subclass of: Incorrect Control Flow Scoping
cwe-id: CWE-397

Path Traversal: '\\UNC\share\name\' (Windows UNC Share)
type: Class
subclass of: Absolute Path Traversal
cwe-id: CWE-40

Uncontrolled Resource Consumption
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-400

Missing Release of Memory after Effective Lifetime
type: Class
subclass of: Missing Release of Resource after Effective Lifetime
cwe-id: CWE-401

Transmission of Private Resources into a New Sphere ('Resource Leak')
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-402

Exposure of File Descriptor to Unintended Control Sphere ('File Descriptor Leak')
type: Class
subclass of: Transmission of Private Resources into a New Sphere ('Resource Leak')
cwe-id: CWE-403

Improper Resource Shutdown or Release
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-404

Asymmetric Resource Consumption (Amplification)
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-405

Insufficient Control of Network Message Volume (Network Amplification)
type: Class
subclass of: Asymmetric Resource Consumption (Amplification)
cwe-id: CWE-406

Inefficient Algorithmic Complexity
type: Class
subclass of: Asymmetric Resource Consumption (Amplification)
cwe-id: CWE-407

Incorrect Behavior Order: Early Amplification
type: Class
subclass of: Asymmetric Resource Consumption (Amplification)
subclass of: Incorrect Behavior Order
cwe-id: CWE-408

Improper Handling of Highly Compressed Data (Data Amplification)
type: Class
subclass of: Asymmetric Resource Consumption (Amplification)
cwe-id: CWE-409

Improper Resolution of Path Equivalence
type: Class
subclass of: Use of Incorrectly-Resolved Name or Reference
cwe-id: CWE-41

Insufficient Resource Pool
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-410

Unrestricted Externally Accessible Lock
type: Class
subclass of: Improper Locking
cwe-id: CWE-412

Improper Resource Locking
type: Class
subclass of: Improper Locking
cwe-id: CWE-413

Missing Lock Check
type: Class
subclass of: Improper Locking
cwe-id: CWE-414

Double Free
type: Class
subclass of: Multiple Releases of Same Resource or Handle
subclass of: Operation on Resource in Wrong Phase of Lifetime
subclass of: Expired Pointer Dereference
subclass of: Restriction
  on property: weakness-of
  some values from: Memory Free Function
type: NamedIndividual
weakness-of: Memory Free Function
cwe-id: CWE-415

Use After Free
type: Class
subclass of: Expired Pointer Dereference
cwe-id: CWE-416

Unprotected Primary Channel
type: Class
subclass of: Improper Restriction of Communication Channel to Intended Endpoints
cwe-id: CWE-419

Path Equivalence: 'filename.' (Trailing Dot)
type: Class
subclass of: Improper Neutralization of Trailing Special Elements
subclass of: Improper Resolution of Path Equivalence
cwe-id: CWE-42

Unprotected Alternate Channel
type: Class
subclass of: Improper Restriction of Communication Channel to Intended Endpoints
cwe-id: CWE-420

Race Condition During Access to Alternate Channel
type: Class
subclass of: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
subclass of: Unprotected Alternate Channel
cwe-id: CWE-421

Unprotected Windows Messaging Channel ('Shatter')
type: Class
subclass of: Trust of System Event Data
subclass of: Unprotected Alternate Channel
cwe-id: CWE-422

Improper Protection of Alternate Path
type: Class
subclass of: Not Using Complete Mediation
subclass of: Protection Mechanism Failure
cwe-id: CWE-424

Direct Request ('Forced Browsing')
type: Class
subclass of: Authentication Bypass Using an Alternate Path or Channel
subclass of: Improper Protection of Alternate Path
subclass of: Missing Authorization
cwe-id: CWE-425

Untrusted Search Path
type: Class
subclass of: External Control of Critical State Data
subclass of: External Influence of Sphere Definition
cwe-id: CWE-426

Uncontrolled Search Path Element
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-427

Unquoted Search Path or Element
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-428

Path Equivalence: 'filename....' (Multiple Trailing Dot)
type: Class
subclass of: Improper Neutralization of Multiple Trailing Special Elements
subclass of: Path Equivalence: 'filename.' (Trailing Dot)
cwe-id: CWE-43

Deployment of Wrong Handler
type: Class
subclass of: Insufficient Control Flow Management
cwe-id: CWE-430

Missing Handler
type: Class
subclass of: Insufficient Control Flow Management
cwe-id: CWE-431

Dangerous Signal Handler not Disabled During Sensitive Operations
type: Class
subclass of: Signal Handler Race Condition
cwe-id: CWE-432

Unparsed Raw Web Content Delivery
type: Class
subclass of: Storage of File with Sensitive Data Under Web Root
cwe-id: CWE-433

Unrestricted Upload of File with Dangerous Type
type: Class
subclass of: Incorrect Resource Transfer Between Spheres
subclass of: Restriction
  on property: weakness-of
  some values from: User Input Function
type: NamedIndividual
weakness-of: User Input Function
cwe-id: CWE-434

Improper Interaction Between Multiple Correctly-Behaving Entities
type: Class
subclass of: Weakness
cwe-id: CWE-435

Interpretation Conflict
type: Class
subclass of: Improper Interaction Between Multiple Correctly-Behaving Entities
cwe-id: CWE-436

Incomplete Model of Endpoint Features
type: Class
subclass of: Interpretation Conflict
cwe-id: CWE-437

Behavioral Change in New Version or Environment
type: Class
subclass of: Improper Interaction Between Multiple Correctly-Behaving Entities
cwe-id: CWE-439

Path Equivalence: 'file.name' (Internal Dot)
type: Class
subclass of: Improper Resolution of Path Equivalence
cwe-id: CWE-44

Expected Behavior Violation
type: Class
subclass of: Incorrect Provision of Specified Functionality
cwe-id: CWE-440

Unintended Proxy or Intermediary ('Confused Deputy')
type: Class
subclass of: Externally Controlled Reference to a Resource in Another Sphere
cwe-id: CWE-441

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
type: Class
subclass of: Interpretation Conflict
cwe-id: CWE-444

UI Discrepancy for Security Feature
type: Class
subclass of: Incorrect Provision of Specified Functionality
cwe-id: CWE-446

Unimplemented or Unsupported Feature in UI
type: Class
subclass of: UI Discrepancy for Security Feature
subclass of: Lack of Administrator Control over Security
cwe-id: CWE-447

Obsolete Feature in UI
type: Class
subclass of: UI Discrepancy for Security Feature
cwe-id: CWE-448

The UI Performs the Wrong Action
type: Class
subclass of: UI Discrepancy for Security Feature
cwe-id: CWE-449

Path Equivalence: 'file...name' (Multiple Internal Dot)
type: Class
subclass of: Improper Neutralization of Multiple Internal Special Elements
subclass of: Path Equivalence: 'file.name' (Internal Dot)
cwe-id: CWE-45

Multiple Interpretations of UI Input
type: Class
subclass of: Insufficient UI Warning of Dangerous Operations
cwe-id: CWE-450

User Interface (UI) Misrepresentation of Critical Information
type: Class
subclass of: Information Loss or Omission
subclass of: Incorrect Provision of Specified Functionality
cwe-id: CWE-451

Insecure Default Variable Initialization
type: Class
subclass of: Insecure Default Initialization of Resource
cwe-id: CWE-453

External Initialization of Trusted Variables or Data Stores
type: Class
subclass of: Improper Initialization
cwe-id: CWE-454

Non-exit on Failed Initialization
type: Class
subclass of: Not Failing Securely ('Failing Open')
subclass of: Improper Initialization
subclass of: Incorrect Control Flow Scoping
cwe-id: CWE-455

Missing Initialization of a Variable
type: Class
subclass of: Missing Initialization of Resource
cwe-id: CWE-456

Use of Uninitialized Variable
type: Class
subclass of: Use of Uninitialized Resource
cwe-id: CWE-457

Incomplete Cleanup
type: Class
subclass of: Improper Resource Shutdown or Release
cwe-id: CWE-459

Path Equivalence: 'filename ' (Trailing Space)
type: Class
subclass of: Improper Neutralization of Trailing Special Elements
subclass of: Improper Resolution of Path Equivalence
cwe-id: CWE-46

Improper Cleanup on Thrown Exception
type: Class
subclass of: Incomplete Cleanup
subclass of: Improper Handling of Exceptional Conditions
cwe-id: CWE-460

Duplicate Key in Associative List (Alist)
type: Class
subclass of: Use of Multiple Resources with Duplicate Identifier
cwe-id: CWE-462

Deletion of Data Structure Sentinel
type: Class
subclass of: Improper Neutralization
cwe-id: CWE-463

Addition of Data Structure Sentinel
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-464

Return of Pointer Value Outside of Expected Range
type: Class
subclass of: Improper Restriction of Operations within the Bounds of a Memory Buffer
cwe-id: CWE-466

Use of sizeof() on a Pointer Type
type: Class
subclass of: Incorrect Calculation of Buffer Size
cwe-id: CWE-467

Incorrect Pointer Scaling
type: Class
subclass of: Incorrect Calculation
cwe-id: CWE-468

Use of Pointer Subtraction to Determine Size
type: Class
subclass of: Incorrect Calculation
cwe-id: CWE-469

Path Equivalence: ' filename' (Leading Space)
type: Class
subclass of: Improper Resolution of Path Equivalence
cwe-id: CWE-47

Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')
type: Class
subclass of: Externally Controlled Reference to a Resource in Another Sphere
subclass of: Improper Control of Dynamically-Managed Code Resources
cwe-id: CWE-470

Modification of Assumed-Immutable Data (MAID)
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-471

External Control of Assumed-Immutable Web Parameter
type: Class
subclass of: Modification of Assumed-Immutable Data (MAID)
subclass of: External Control of Critical State Data
cwe-id: CWE-472

PHP External Variable Modification
type: Class
subclass of: Modification of Assumed-Immutable Data (MAID)
cwe-id: CWE-473

Use of Function with Inconsistent Implementations
type: Class
subclass of: Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
cwe-id: CWE-474

Undefined Behavior for Input to API
type: Class
subclass of: Improper Following of Specification by Caller
cwe-id: CWE-475

NULL Pointer Dereference
type: Class
subclass of: Improper Adherence to Coding Standards
subclass of: Improper Check for Unusual or Exceptional Conditions
subclass of: Restriction
  on property: weakness-of
  some values from: Pointer Dereferencing Function
type: NamedIndividual
weakness-of: Pointer Dereferencing Function
cwe-id: CWE-476

Use of Obsolete Function
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-477

Missing Default Case in Multiple Condition Expression
type: Class
subclass of: Incomplete Comparison with Missing Factors
cwe-id: CWE-478

Signal Handler Use of a Non-reentrant Function
type: Class
subclass of: Use of a Non-reentrant Function in a Concurrent Context
subclass of: Signal Handler with Functionality that is not Asynchronous-Safe
cwe-id: CWE-479

Path Equivalence: 'file name' (Internal Whitespace)
type: Class
subclass of: Improper Resolution of Path Equivalence
cwe-id: CWE-48

Use of Incorrect Operator
type: Class
subclass of: Always-Incorrect Control Flow Implementation
cwe-id: CWE-480

Assigning instead of Comparing
type: Class
subclass of: Use of Incorrect Operator
cwe-id: CWE-481

Comparing instead of Assigning
type: Class
subclass of: Use of Incorrect Operator
cwe-id: CWE-482

Incorrect Block Delimitation
type: Class
subclass of: Always-Incorrect Control Flow Implementation
cwe-id: CWE-483

Omitted Break Statement in Switch
type: Class
subclass of: Always-Incorrect Control Flow Implementation
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-484

Comparison of Classes by Name
type: Class
subclass of: Comparison Using Wrong Factors
cwe-id: CWE-486

Reliance on Package-level Scope
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-487

Exposure of Data Element to Wrong Session
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-488

Active Debug Code
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-489

Path Equivalence: 'filename/' (Trailing Slash)
type: Class
subclass of: Improper Neutralization of Trailing Special Elements
subclass of: Improper Resolution of Path Equivalence
cwe-id: CWE-49

Public cloneable() Method Without Final ('Object Hijack')
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-491

Use of Inner Class Containing Sensitive Data
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-492

Critical Public Variable Without Final Modifier
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-493

Download of Code Without Integrity Check
type: Class
subclass of: Insufficient Verification of Data Authenticity
subclass of: Incorrect Resource Transfer Between Spheres
cwe-id: CWE-494

Private Data Structure Returned From A Public Method
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-495

Public Data Assigned to Private Array-Typed Field
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-496

Exposure of Sensitive System Information to an Unauthorized Control Sphere
type: Class
subclass of: Exposure of Sensitive Information to an Unauthorized Actor
cwe-id: CWE-497

Cloneable Class Containing Sensitive Information
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-498

Serializable Class Containing Sensitive Data
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-499

J2EE Misconfiguration: Data Transmission Without Encryption
type: Class
subclass of: Cleartext Transmission of Sensitive Information
cwe-id: CWE-5

Path Equivalence: '//multiple/leading/slash'
type: Class
subclass of: Improper Neutralization of Multiple Leading Special Elements
subclass of: Improper Resolution of Path Equivalence
cwe-id: CWE-50

Public Static Field Not Marked Final
type: Class
subclass of: Critical Public Variable Without Final Modifier
cwe-id: CWE-500

Trust Boundary Violation
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-501

Deserialization of Untrusted Data
type: Class
subclass of: Improper Control of Dynamically-Managed Code Resources
subclass of: Restriction
  on property: may-be-weakness-of
  some values from: User Input Function
subclass of: Restriction
  on property: weakness-of
  some values from: Deserialization Function
type: NamedIndividual
may-be-weakness-of: User Input Function
weakness-of: Deserialization Function
cwe-id: CWE-502

Embedded Malicious Code
type: Class
subclass of: Hidden Functionality
cwe-id: CWE-506

Trojan Horse
type: Class
subclass of: Embedded Malicious Code
cwe-id: CWE-507

Non-Replicating Malicious Code
type: Class
subclass of: Trojan Horse
cwe-id: CWE-508

Replicating Malicious Code (Virus or Worm)
type: Class
subclass of: Trojan Horse
cwe-id: CWE-509

Path Equivalence: '/multiple//internal/slash'
type: Class
subclass of: Improper Resolution of Path Equivalence
cwe-id: CWE-51

Trapdoor
type: Class
subclass of: Embedded Malicious Code
cwe-id: CWE-510

Logic/Time Bomb
type: Class
subclass of: Embedded Malicious Code
cwe-id: CWE-511

Spyware
type: Class
subclass of: Embedded Malicious Code
cwe-id: CWE-512

Covert Channel
type: Class
subclass of: Creation of Emergent Resource
cwe-id: CWE-514

Covert Storage Channel
type: Class
subclass of: Covert Channel
cwe-id: CWE-515

Path Equivalence: '/multiple/trailing/slash//'
type: Class
subclass of: Improper Neutralization of Multiple Trailing Special Elements
subclass of: Improper Resolution of Path Equivalence
cwe-id: CWE-52

.NET Misconfiguration: Use of Impersonation
type: Class
subclass of: Incorrect Privilege Assignment
cwe-id: CWE-520

Weak Password Requirements
type: Class
subclass of: Use of Weak Credentials
cwe-id: CWE-521

Insufficiently Protected Credentials
type: Class
subclass of: Weak Authentication
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-522

Unprotected Transport of Credentials
type: Class
subclass of: Insufficiently Protected Credentials
cwe-id: CWE-523

Use of Cache Containing Sensitive Information
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-524

Use of Web Browser Cache Containing Sensitive Information
type: Class
subclass of: Use of Cache Containing Sensitive Information
cwe-id: CWE-525

Cleartext Storage of Sensitive Information in an Environment Variable
type: Class
subclass of: Cleartext Storage of Sensitive Information
cwe-id: CWE-526

Exposure of Version-Control Repository to an Unauthorized Control Sphere
type: Class
subclass of: Files or Directories Accessible to External Parties
cwe-id: CWE-527

Exposure of Core Dump File to an Unauthorized Control Sphere
type: Class
subclass of: Files or Directories Accessible to External Parties
cwe-id: CWE-528

Exposure of Access Control List Files to an Unauthorized Control Sphere
type: Class
subclass of: Files or Directories Accessible to External Parties
cwe-id: CWE-529

Path Equivalence: '\multiple\\internal\backslash'
type: Class
subclass of: Improper Neutralization of Multiple Internal Special Elements
subclass of: Improper Resolution of Path Equivalence
cwe-id: CWE-53

Exposure of Backup File to an Unauthorized Control Sphere
type: Class
subclass of: Files or Directories Accessible to External Parties
cwe-id: CWE-530

Inclusion of Sensitive Information in Test Code
type: Class
subclass of: Inclusion of Sensitive Information in Source Code
cwe-id: CWE-531

Insertion of Sensitive Information into Log File
type: Class
subclass of: Insertion of Sensitive Information into Externally-Accessible File or Directory
cwe-id: CWE-532

Exposure of Information Through Shell Error Message
type: Class
subclass of: Externally-Generated Error Message Containing Sensitive Information
cwe-id: CWE-535

Servlet Runtime Error Message Containing Sensitive Information
type: Class
subclass of: Externally-Generated Error Message Containing Sensitive Information
cwe-id: CWE-536

Java Runtime Error Message Containing Sensitive Information
type: Class
subclass of: Externally-Generated Error Message Containing Sensitive Information
cwe-id: CWE-537

Insertion of Sensitive Information into Externally-Accessible File or Directory
type: Class
subclass of: Exposure of Sensitive Information to an Unauthorized Actor
cwe-id: CWE-538

Use of Persistent Cookies Containing Sensitive Information
type: Class
subclass of: Files or Directories Accessible to External Parties
cwe-id: CWE-539

Path Equivalence: 'filedir\' (Trailing Backslash)
type: Class
subclass of: Improper Neutralization of Trailing Special Elements
subclass of: Improper Resolution of Path Equivalence
cwe-id: CWE-54

Inclusion of Sensitive Information in Source Code
type: Class
subclass of: Insertion of Sensitive Information into Externally-Accessible File or Directory
cwe-id: CWE-540

Inclusion of Sensitive Information in an Include File
type: Class
subclass of: Inclusion of Sensitive Information in Source Code
cwe-id: CWE-541

Use of Singleton Pattern Without Synchronization in a Multithreaded Context
type: Class
subclass of: Missing Synchronization
cwe-id: CWE-543

Missing Standardized Error Handling Mechanism
type: Class
subclass of: Improper Handling of Exceptional Conditions
cwe-id: CWE-544

Suspicious Comment
type: Class
subclass of: Inappropriate Source Code Style or Formatting
cwe-id: CWE-546

Use of Hard-coded, Security-relevant Constants
type: Class
subclass of: Inappropriate Source Code Style or Formatting
cwe-id: CWE-547

Exposure of Information Through Directory Listing
type: Class
subclass of: Exposure of Sensitive System Information to an Unauthorized Control Sphere
cwe-id: CWE-548

Missing Password Field Masking
type: Class
subclass of: Insufficiently Protected Credentials
cwe-id: CWE-549

Path Equivalence: '/./' (Single Dot Directory)
type: Class
subclass of: Improper Resolution of Path Equivalence
cwe-id: CWE-55

Server-generated Error Message Containing Sensitive Information
type: Class
subclass of: Generation of Error Message Containing Sensitive Information
cwe-id: CWE-550

Incorrect Behavior Order: Authorization Before Parsing and Canonicalization
type: Class
subclass of: Incorrect Behavior Order
subclass of: Incorrect Authorization
cwe-id: CWE-551

Files or Directories Accessible to External Parties
type: Class
subclass of: Improper Authorization
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-552

Command Shell in Externally Accessible Directory
type: Class
subclass of: Files or Directories Accessible to External Parties
cwe-id: CWE-553

ASP.NET Misconfiguration: Not Using Input Validation Framework
type: Class
subclass of: Improper Use of Validation Framework
cwe-id: CWE-554

J2EE Misconfiguration: Plaintext Password in Configuration File
type: Class
subclass of: Password in Configuration File
cwe-id: CWE-555

ASP.NET Misconfiguration: Use of Identity Impersonation
type: Class
subclass of: Incorrect Privilege Assignment
cwe-id: CWE-556

Use of getlogin() in Multithreaded Application
type: Class
subclass of: Use of a Non-reentrant Function in a Concurrent Context
cwe-id: CWE-558

Path Equivalence: 'filedir*' (Wildcard)
type: Class
subclass of: Improper Neutralization of Wildcards or Matching Symbols
subclass of: Improper Resolution of Path Equivalence
cwe-id: CWE-56

Use of umask() with chmod-style Argument
type: Class
subclass of: Function Call With Incorrectly Specified Argument Value
cwe-id: CWE-560

Dead Code
type: Class
subclass of: Irrelevant Code
cwe-id: CWE-561

Return of Stack Variable Address
type: Class
subclass of: Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
cwe-id: CWE-562

Assignment to Variable without Use
type: Class
subclass of: Irrelevant Code
cwe-id: CWE-563

SQL Injection: Hibernate
type: Class
subclass of: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
cwe-id: CWE-564

Reliance on Cookies without Validation and Integrity Checking
type: Class
subclass of: Client-Side Enforcement of Server-Side Security
subclass of: External Control of Critical State Data
cwe-id: CWE-565

Authorization Bypass Through User-Controlled SQL Primary Key
type: Class
subclass of: Authorization Bypass Through User-Controlled Key
cwe-id: CWE-566

Unsynchronized Access to Shared Data in a Multithreaded Context
type: Class
subclass of: Missing Synchronization
cwe-id: CWE-567

finalize() Method Without super.finalize()
type: Class
subclass of: Incomplete Cleanup
subclass of: Improper Following of Specification by Caller
cwe-id: CWE-568

Path Equivalence: 'fakedir/../realdir/filename'
type: Class
subclass of: Improper Resolution of Path Equivalence
cwe-id: CWE-57

Expression is Always False
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-570

Expression is Always True
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-571

Call to Thread run() instead of start()
type: Class
subclass of: Incorrect Synchronization
cwe-id: CWE-572

Improper Following of Specification by Caller
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-573

EJB Bad Practices: Use of Synchronization Primitives
type: Class
subclass of: Use of Low-Level Functionality
subclass of: Incorrect Synchronization
cwe-id: CWE-574

EJB Bad Practices: Use of AWT Swing
type: Class
subclass of: Use of Low-Level Functionality
cwe-id: CWE-575

EJB Bad Practices: Use of Java I/O
type: Class
subclass of: Use of Low-Level Functionality
cwe-id: CWE-576

EJB Bad Practices: Use of Sockets
type: Class
subclass of: Improper Following of Specification by Caller
cwe-id: CWE-577

EJB Bad Practices: Use of Class Loader
type: Class
subclass of: Improper Following of Specification by Caller
cwe-id: CWE-578

J2EE Bad Practices: Non-serializable Object Stored in Session
type: Class
subclass of: Improper Following of Specification by Caller
cwe-id: CWE-579

Path Equivalence: Windows 8.3 Filename
type: Class
subclass of: Improper Resolution of Path Equivalence
cwe-id: CWE-58

clone() Method Without super.clone()
type: Class
subclass of: Improper Following of Specification by Caller
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-580

Object Model Violation: Just One of Equals and Hashcode Defined
type: Class
subclass of: Improper Following of Specification by Caller
subclass of: Incorrect Comparison
cwe-id: CWE-581

Array Declared Public, Final, and Static
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-582

finalize() Method Declared Public
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-583

Return Inside Finally Block
type: Class
subclass of: Incorrect Control Flow Scoping
cwe-id: CWE-584

Empty Synchronized Block
type: Class
subclass of: Empty Code Block
cwe-id: CWE-585

Explicit Call to Finalize()
type: Class
subclass of: Insufficient Adherence to Expected Conventions
cwe-id: CWE-586

Assignment of a Fixed Address to a Pointer
type: Class
subclass of: Use of Invariant Value in Dynamically Changing Context
subclass of: Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
cwe-id: CWE-587

Attempt to Access Child of a Non-structure Pointer
type: Class
subclass of: Incorrect Type Conversion or Cast
subclass of: Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
cwe-id: CWE-588

Call to Non-ubiquitous API
type: Class
subclass of: Use of Function with Inconsistent Implementations
cwe-id: CWE-589

Improper Link Resolution Before File Access ('Link Following')
type: Class
subclass of: Use of Incorrectly-Resolved Name or Reference
cwe-id: CWE-59

Free of Memory not on the Heap
type: Class
subclass of: Mismatched Memory Management Routines
subclass of: Restriction
  on property: weakness-of
  some values from: Memory Free Function
type: NamedIndividual
weakness-of: Memory Free Function
cwe-id: CWE-590

Sensitive Data Storage in Improperly Locked Memory
type: Class
subclass of: Improper Resource Locking
cwe-id: CWE-591

Authentication Bypass: OpenSSL CTX Object Modified after SSL Objects are Created
type: Class
subclass of: Weak Authentication
subclass of: Operation on Resource in Wrong Phase of Lifetime
cwe-id: CWE-593

J2EE Framework: Saving Unserializable Objects to Disk
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-594

Comparison of Object References Instead of Object Contents
type: Class
subclass of: Comparison Using Wrong Factors
cwe-id: CWE-595

Use of Wrong Operator in String Comparison
type: Class
subclass of: Use of Incorrect Operator
subclass of: Comparison of Object References Instead of Object Contents
cwe-id: CWE-597

Use of GET Request Method With Sensitive Query Strings
type: Class
subclass of: Insertion of Sensitive Information Into Sent Data
cwe-id: CWE-598

Missing Validation of OpenSSL Certificate
type: Class
subclass of: Improper Certificate Validation
cwe-id: CWE-599

J2EE Misconfiguration: Insufficient Session-ID Length
type: Class
subclass of: Small Space of Random Values
cwe-id: CWE-6

Uncaught Exception in Servlet
type: Class
subclass of: Uncaught Exception
cwe-id: CWE-600

URL Redirection to Untrusted Site ('Open Redirect')
type: Class
subclass of: Externally Controlled Reference to a Resource in Another Sphere
cwe-id: CWE-601

Client-Side Enforcement of Server-Side Security
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-602

Use of Client-Side Authentication
type: Class
subclass of: Weak Authentication
subclass of: Client-Side Enforcement of Server-Side Security
cwe-id: CWE-603

Multiple Binds to the Same Port
type: Class
subclass of: Operation on Resource in Wrong Phase of Lifetime
subclass of: Multiple Operations on Resource in Single-Operation Context
cwe-id: CWE-605

Unchecked Input for Loop Condition
type: Class
subclass of: Improper Validation of Specified Quantity in Input
cwe-id: CWE-606

Public Static Final Field References Mutable Object
type: Class
subclass of: Modification of Assumed-Immutable Data (MAID)
cwe-id: CWE-607

Struts: Non-private Field in ActionForm Class
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-608

Double-Checked Locking
type: Class
subclass of: Improper Locking
cwe-id: CWE-609

UNIX Symbolic Link (Symlink) Following
type: Class
subclass of: Improper Link Resolution Before File Access ('Link Following')
cwe-id: CWE-61

Externally Controlled Reference to a Resource in Another Sphere
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-610

Improper Restriction of XML External Entity Reference
type: Class
subclass of: Externally Controlled Reference to a Resource in Another Sphere
subclass of: Restriction
  on property: weakness-of
  some values from: External Content Inclusion Function
type: NamedIndividual
weakness-of: External Content Inclusion Function
cwe-id: CWE-611

Improper Authorization of Index Containing Sensitive Information
type: Class
subclass of: Exposure of Sensitive Information Through Metadata
cwe-id: CWE-612

Insufficient Session Expiration
type: Class
subclass of: Operation on a Resource after Expiration or Release
cwe-id: CWE-613

Sensitive Cookie in HTTPS Session Without 'Secure' Attribute
type: Class
subclass of: Cleartext Transmission of Sensitive Information
cwe-id: CWE-614

Inclusion of Sensitive Information in Source Code Comments
type: Class
subclass of: Inclusion of Sensitive Information in Source Code
cwe-id: CWE-615

Incomplete Identification of Uploaded File Variables (PHP)
type: Class
subclass of: Insufficient Verification of Data Authenticity
cwe-id: CWE-616

Reachable Assertion
type: Class
subclass of: Always-Incorrect Control Flow Implementation
cwe-id: CWE-617

Exposed Unsafe ActiveX Method
type: Class
subclass of: Exposed Dangerous Method or Function
cwe-id: CWE-618

Dangling Database Cursor ('Cursor Injection')
type: Class
subclass of: Transmission of Private Resources into a New Sphere ('Resource Leak')
cwe-id: CWE-619

UNIX Hard Link
type: Class
subclass of: Improper Link Resolution Before File Access ('Link Following')
cwe-id: CWE-62

Unverified Password Change
type: Class
subclass of: Weak Authentication
cwe-id: CWE-620

Variable Extraction Error
type: Class
subclass of: Improper Control of Dynamically-Identified Variables
cwe-id: CWE-621

Improper Validation of Function Hook Arguments
type: Class
subclass of: Improper Input Validation
cwe-id: CWE-622

Unsafe ActiveX Control Marked Safe For Scripting
type: Class
subclass of: Privilege Defined With Unsafe Actions
cwe-id: CWE-623

Executable Regular Expression Error
type: Class
subclass of: Improper Neutralization of Special Elements used in a Command ('Command Injection')
cwe-id: CWE-624

Permissive Regular Expression
type: Class
subclass of: Incorrect Regular Expression
cwe-id: CWE-625

Null Byte Interaction Error (Poison Null Byte)
type: Class
subclass of: Improper Neutralization of Input Terminators
subclass of: Interpretation Conflict
cwe-id: CWE-626

Dynamic Variable Evaluation
type: Class
subclass of: Improper Control of Dynamically-Identified Variables
cwe-id: CWE-627

Function Call with Incorrectly Specified Arguments
type: Class
subclass of: Improper Following of Specification by Caller
cwe-id: CWE-628

Not Failing Securely ('Failing Open')
type: Class
subclass of: Violation of Secure Design Principles
subclass of: Improper Handling of Exceptional Conditions
cwe-id: CWE-636

Unnecessary Complexity in Protection Mechanism (Not Using 'Economy of Mechanism')
type: Class
subclass of: Violation of Secure Design Principles
cwe-id: CWE-637

Not Using Complete Mediation
type: Class
subclass of: Violation of Secure Design Principles
subclass of: Missing Authorization
cwe-id: CWE-638

Authorization Bypass Through User-Controlled Key
type: Class
subclass of: Incorrect Authorization
cwe-id: CWE-639

Windows Shortcut Following (.LNK)
type: Class
subclass of: Improper Link Resolution Before File Access ('Link Following')
cwe-id: CWE-64

Weak Password Recovery Mechanism for Forgotten Password
type: Class
subclass of: Weak Authentication
cwe-id: CWE-640

Improper Restriction of Names for Files and Other Resources
type: Class
subclass of: Improper Control of Resource Identifiers ('Resource Injection')
cwe-id: CWE-641

External Control of Critical State Data
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-642

Improper Neutralization of Data within XPath Expressions ('XPath Injection')
type: Class
subclass of: XML Injection (aka Blind XPath Injection)
subclass of: Improper Neutralization of Special Elements in Data Query Logic
cwe-id: CWE-643

Improper Neutralization of HTTP Headers for Scripting Syntax
type: Class
subclass of: Improper Encoding or Escaping of Output
cwe-id: CWE-644

Overly Restrictive Account Lockout Mechanism
type: Class
subclass of: Improper Authentication
cwe-id: CWE-645

Reliance on File Name or Extension of Externally-Supplied File
type: Class
subclass of: Insufficient Verification of Data Authenticity
cwe-id: CWE-646

Use of Non-Canonical URL Paths for Authorization Decisions
type: Class
subclass of: Incorrect Authorization
cwe-id: CWE-647

Incorrect Use of Privileged APIs
type: Class
subclass of: Improper Privilege Management
cwe-id: CWE-648

Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking
type: Class
subclass of: Insufficient Verification of Data Authenticity
cwe-id: CWE-649

Windows Hard Link
type: Class
subclass of: Improper Link Resolution Before File Access ('Link Following')
cwe-id: CWE-65

Trusting HTTP Permission Methods on the Server Side
type: Class
subclass of: Interpretation Conflict
cwe-id: CWE-650

Exposure of WSDL File Containing Sensitive Information
type: Class
subclass of: Insertion of Sensitive Information into Externally-Accessible File or Directory
cwe-id: CWE-651

Improper Neutralization of Data within XQuery Expressions ('XQuery Injection')
type: Class
subclass of: XML Injection (aka Blind XPath Injection)
subclass of: Improper Neutralization of Special Elements in Data Query Logic
cwe-id: CWE-652

Improper Isolation or Compartmentalization
type: Class
subclass of: Violation of Secure Design Principles
subclass of: Protection Mechanism Failure
cwe-id: CWE-653

Reliance on a Single Factor in a Security Decision
type: Class
subclass of: Violation of Secure Design Principles
subclass of: Protection Mechanism Failure
cwe-id: CWE-654

Insufficient Psychological Acceptability
type: Class
subclass of: Violation of Secure Design Principles
subclass of: Protection Mechanism Failure
cwe-id: CWE-655

Reliance on Security Through Obscurity
type: Class
subclass of: Violation of Secure Design Principles
subclass of: Protection Mechanism Failure
cwe-id: CWE-656

Violation of Secure Design Principles
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-657

Improper Handling of File Names that Identify Virtual Resources
type: Class
subclass of: Use of Incorrectly-Resolved Name or Reference
cwe-id: CWE-66

Improper Synchronization
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
subclass of: Insufficient Control Flow Management
cwe-id: CWE-662

Use of a Non-reentrant Function in a Concurrent Context
type: Class
subclass of: Improper Synchronization
cwe-id: CWE-663

Improper Control of a Resource Through its Lifetime
type: Class
subclass of: Weakness
cwe-id: CWE-664

Improper Initialization
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-665

Operation on Resource in Wrong Phase of Lifetime
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-666

Improper Locking
type: Class
subclass of: Improper Synchronization
cwe-id: CWE-667

Exposure of Resource to Wrong Sphere
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-668

Incorrect Resource Transfer Between Spheres
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-669

Improper Handling of Windows Device Names
type: Class
subclass of: Improper Handling of File Names that Identify Virtual Resources
cwe-id: CWE-67

Always-Incorrect Control Flow Implementation
type: Class
subclass of: Insufficient Control Flow Management
cwe-id: CWE-670

Lack of Administrator Control over Security
type: Class
subclass of: Violation of Secure Design Principles
cwe-id: CWE-671

Operation on a Resource after Expiration or Release
type: Class
subclass of: Operation on Resource in Wrong Phase of Lifetime
cwe-id: CWE-672

External Influence of Sphere Definition
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-673

Uncontrolled Recursion
type: Class
subclass of: Excessive Iteration
cwe-id: CWE-674

Multiple Operations on Resource in Single-Operation Context
type: Class
subclass of: Improper Following of Specification by Caller
cwe-id: CWE-675

Use of Potentially Dangerous Function
type: Class
subclass of: Use of Prohibited Code
cwe-id: CWE-676

Integer Overflow to Buffer Overflow
type: Class
subclass of: Improper Restriction of Operations within the Bounds of a Memory Buffer
cwe-id: CWE-680

Incorrect Conversion between Numeric Types
type: Class
subclass of: Incorrect Type Conversion or Cast
cwe-id: CWE-681

Incorrect Calculation
type: Class
subclass of: Weakness
cwe-id: CWE-682

Function Call With Incorrect Order of Arguments
type: Class
subclass of: Function Call with Incorrectly Specified Arguments
cwe-id: CWE-683

Incorrect Provision of Specified Functionality
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-684

Function Call With Incorrect Number of Arguments
type: Class
subclass of: Function Call with Incorrectly Specified Arguments
cwe-id: CWE-685

Function Call With Incorrect Argument Type
type: Class
subclass of: Function Call with Incorrectly Specified Arguments
cwe-id: CWE-686

Function Call With Incorrectly Specified Argument Value
type: Class
subclass of: Function Call with Incorrectly Specified Arguments
cwe-id: CWE-687

Function Call With Incorrect Variable or Reference as Argument
type: Class
subclass of: Function Call with Incorrectly Specified Arguments
cwe-id: CWE-688

Permission Race Condition During Resource Copy
type: Class
subclass of: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
cwe-id: CWE-689

Improper Handling of Windows ::DATA Alternate Data Stream
type: Class
subclass of: Improper Handling of File Names that Identify Virtual Resources
cwe-id: CWE-69

Unchecked Return Value to NULL Pointer Dereference
type: Class
subclass of: NULL Pointer Dereference
cwe-id: CWE-690

Insufficient Control Flow Management
type: Class
subclass of: Weakness
cwe-id: CWE-691

Incomplete Denylist to Cross-Site Scripting
type: Class
subclass of: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
cwe-id: CWE-692

Protection Mechanism Failure
type: Class
subclass of: Weakness
cwe-id: CWE-693

Use of Multiple Resources with Duplicate Identifier
type: Class
subclass of: Improper Following of Specification by Caller
subclass of: Improper Control of Resource Identifiers ('Resource Injection')
cwe-id: CWE-694

Use of Low-Level Functionality
type: Class
subclass of: Improper Following of Specification by Caller
cwe-id: CWE-695

Incorrect Behavior Order
type: Class
subclass of: Insufficient Control Flow Management
cwe-id: CWE-696

Incorrect Comparison
type: Class
subclass of: Weakness
cwe-id: CWE-697

Execution After Redirect (EAR)
type: Class
subclass of: Always-Incorrect Control Flow Implementation
subclass of: Incorrect Control Flow Scoping
cwe-id: CWE-698

J2EE Misconfiguration: Missing Custom Error Page
type: Class
subclass of: Missing Custom Error Page
cwe-id: CWE-7

Improper Check or Handling of Exceptional Conditions
type: Class
subclass of: Weakness
cwe-id: CWE-703

Incorrect Type Conversion or Cast
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-704

Incorrect Control Flow Scoping
type: Class
subclass of: Insufficient Control Flow Management
cwe-id: CWE-705

Use of Incorrectly-Resolved Name or Reference
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-706

Improper Neutralization
type: Class
subclass of: Weakness
cwe-id: CWE-707

Incorrect Ownership Assignment
type: Class
subclass of: Improper Ownership Management
cwe-id: CWE-708

Improper Adherence to Coding Standards
type: Class
subclass of: Weakness
cwe-id: CWE-710

Improper Handling of Apple HFS+ Alternate Data Stream Path
type: Class
subclass of: Improper Handling of File Names that Identify Virtual Resources
cwe-id: CWE-72

External Control of File Name or Path
type: Class
subclass of: Externally Controlled Reference to a Resource in Another Sphere
subclass of: External Control of Critical State Data
cwe-id: CWE-73

Incorrect Permission Assignment for Critical Resource
type: Class
subclass of: Improper Authorization
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-732

Compiler Optimization Removal or Modification of Security-critical Code
type: Class
subclass of: Insecure Automated Optimizations
cwe-id: CWE-733

Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
type: Class
subclass of: Improper Neutralization
cwe-id: CWE-74

Exposed Dangerous Method or Function
type: Class
subclass of: Improper Access Control
cwe-id: CWE-749

Failure to Sanitize Special Elements into a Different Plane (Special Element Injection)
type: Class
subclass of: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
cwe-id: CWE-75

Improper Check for Unusual or Exceptional Conditions
type: Class
subclass of: Improper Check or Handling of Exceptional Conditions
cwe-id: CWE-754

Improper Handling of Exceptional Conditions
type: Class
subclass of: Improper Check or Handling of Exceptional Conditions
cwe-id: CWE-755

Missing Custom Error Page
type: Class
subclass of: Improper Handling of Exceptional Conditions
cwe-id: CWE-756

Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-757

Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
type: Class
subclass of: Improper Adherence to Coding Standards
cwe-id: CWE-758

Use of a One-Way Hash without a Salt
type: Class
subclass of: Use of Password Hash With Insufficient Computational Effort
cwe-id: CWE-759

Improper Neutralization of Equivalent Special Elements
type: Class
subclass of: Failure to Sanitize Special Elements into a Different Plane (Special Element Injection)
cwe-id: CWE-76

Use of a One-Way Hash with a Predictable Salt
type: Class
subclass of: Use of Password Hash With Insufficient Computational Effort
cwe-id: CWE-760

Free of Pointer not at Start of Buffer
type: Class
subclass of: Release of Invalid Pointer or Reference
subclass of: Restriction
  on property: weakness-of
  some values from: Memory Free Function
type: NamedIndividual
weakness-of: Memory Free Function
cwe-id: CWE-761

Mismatched Memory Management Routines
type: Class
subclass of: Release of Invalid Pointer or Reference
cwe-id: CWE-762

Release of Invalid Pointer or Reference
type: Class
subclass of: Improper Resource Shutdown or Release
cwe-id: CWE-763

Multiple Locks of a Critical Resource
type: Class
subclass of: Improper Locking
subclass of: Multiple Operations on Resource in Single-Operation Context
cwe-id: CWE-764

Multiple Unlocks of a Critical Resource
type: Class
subclass of: Improper Locking
subclass of: Multiple Operations on Resource in Single-Operation Context
cwe-id: CWE-765

Critical Data Element Declared Public
type: Class
subclass of: Insufficient Encapsulation
cwe-id: CWE-766

Access to Critical Private Variable via Public Method
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-767

Incorrect Short Circuit Evaluation
type: Class
subclass of: Insufficient Control Flow Management
cwe-id: CWE-768

Improper Neutralization of Special Elements used in a Command ('Command Injection')
type: Class
subclass of: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
subclass of: Restriction
  on property: weakness-of
  some values from: User Input Function
type: NamedIndividual
weakness-of: User Input Function
cwe-id: CWE-77

Allocation of Resources Without Limits or Throttling
type: Class
subclass of: Uncontrolled Resource Consumption
subclass of: Improper Initialization
cwe-id: CWE-770

Missing Reference to Active Allocated Resource
type: Class
subclass of: Uncontrolled Resource Consumption
cwe-id: CWE-771

Missing Release of Resource after Effective Lifetime
type: Class
subclass of: Improper Resource Shutdown or Release
cwe-id: CWE-772

Missing Reference to Active File Descriptor or Handle
type: Class
subclass of: Missing Reference to Active Allocated Resource
cwe-id: CWE-773

Allocation of File Descriptors or Handles Without Limits or Throttling
type: Class
subclass of: Allocation of Resources Without Limits or Throttling
cwe-id: CWE-774

Missing Release of File Descriptor or Handle after Effective Lifetime
type: Class
subclass of: Missing Release of Resource after Effective Lifetime
cwe-id: CWE-775

Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
type: Class
subclass of: Asymmetric Resource Consumption (Amplification)
subclass of: Uncontrolled Recursion
cwe-id: CWE-776

Regular Expression without Anchors
type: Class
subclass of: Permissive Regular Expression
cwe-id: CWE-777

Insufficient Logging
type: Class
subclass of: Omission of Security-relevant Information
subclass of: Protection Mechanism Failure
cwe-id: CWE-778

Logging of Excessive Data
type: Class
subclass of: Uncontrolled Resource Consumption
cwe-id: CWE-779

Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
type: Class
subclass of: Improper Neutralization of Special Elements used in a Command ('Command Injection')
subclass of: Restriction
  on property: may-be-weakness-of
  some values from: Eval Function
subclass of: Restriction
  on property: may-be-weakness-of
  some values from: Process Start Function
subclass of: Restriction
  on property: may-be-weakness-of
  some values from: User Input Function
type: NamedIndividual
may-be-weakness-of: Eval Function
may-be-weakness-of: Process Start Function
may-be-weakness-of: User Input Function
cwe-id: CWE-78

Use of RSA Algorithm without OAEP
type: Class
subclass of: Use of a Broken or Risky Cryptographic Algorithm
cwe-id: CWE-780

Improper Address Validation in IOCTL with METHOD_NEITHER I/O Control Code
type: Class
subclass of: Improper Validation of Specified Index, Position, or Offset in Input
cwe-id: CWE-781

Exposed IOCTL with Insufficient Access Control
type: Class
subclass of: Exposed Dangerous Method or Function
cwe-id: CWE-782

Operator Precedence Logic Error
type: Class
subclass of: Always-Incorrect Control Flow Implementation
cwe-id: CWE-783

Reliance on Cookies without Validation and Integrity Checking in a Security Decision
type: Class
subclass of: Reliance on Cookies without Validation and Integrity Checking
subclass of: Reliance on Untrusted Inputs in a Security Decision
cwe-id: CWE-784

Use of Path Manipulation Function without Maximum-sized Buffer
type: Class
subclass of: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
subclass of: Use of Potentially Dangerous Function
cwe-id: CWE-785

Access of Memory Location Before Start of Buffer
type: Class
subclass of: Improper Restriction of Operations within the Bounds of a Memory Buffer
cwe-id: CWE-786

Out-of-bounds Write
type: Class
subclass of: Improper Restriction of Operations within the Bounds of a Memory Buffer
subclass of: Restriction
  on property: weakness-of
  some values from: Raw Memory Access Function
type: NamedIndividual
weakness-of: Raw Memory Access Function
cwe-id: CWE-787

Access of Memory Location After End of Buffer
type: Class
subclass of: Improper Restriction of Operations within the Bounds of a Memory Buffer
cwe-id: CWE-788

Memory Allocation with Excessive Size Value
type: Class
subclass of: Improper Validation of Specified Quantity in Input
subclass of: Allocation of Resources Without Limits or Throttling
cwe-id: CWE-789

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
type: Class
subclass of: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
subclass of: Restriction
  on property: weakness-of
  some values from: User Input Function
type: NamedIndividual
weakness-of: User Input Function
cwe-id: CWE-79

Improper Filtering of Special Elements
type: Class
subclass of: Improper Neutralization of Special Elements
cwe-id: CWE-790

Incomplete Filtering of Special Elements
type: Class
subclass of: Improper Filtering of Special Elements
cwe-id: CWE-791

Incomplete Filtering of One or More Instances of Special Elements
type: Class
subclass of: Incomplete Filtering of Special Elements
cwe-id: CWE-792

Only Filtering One Instance of a Special Element
type: Class
subclass of: Incomplete Filtering of One or More Instances of Special Elements
cwe-id: CWE-793

Incomplete Filtering of Multiple Instances of Special Elements
type: Class
subclass of: Incomplete Filtering of One or More Instances of Special Elements
cwe-id: CWE-794

Only Filtering Special Elements at a Specified Location
type: Class
subclass of: Incomplete Filtering of Special Elements
cwe-id: CWE-795

Only Filtering Special Elements Relative to a Marker
type: Class
subclass of: Only Filtering Special Elements at a Specified Location
cwe-id: CWE-796

Only Filtering Special Elements at an Absolute Position
type: Class
subclass of: Only Filtering Special Elements at a Specified Location
cwe-id: CWE-797

Use of Hard-coded Credentials
type: Class
subclass of: Use of Weak Credentials
subclass of: Use of Invariant Value in Dynamically Changing Context
subclass of: Lack of Administrator Control over Security
subclass of: Restriction
  on property: weakness-of
  some values from: Authentication Function
type: NamedIndividual
weakness-of: Authentication Function
cwe-id: CWE-798

Improper Control of Interaction Frequency
type: Class
subclass of: Insufficient Control Flow Management
cwe-id: CWE-799

J2EE Misconfiguration: Entity Bean Declared Remote
type: Class
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-8

Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
type: Class
subclass of: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
cwe-id: CWE-80

Guessable CAPTCHA
type: Class
subclass of: Weak Authentication
subclass of: Incorrect Authorization
cwe-id: CWE-804

Buffer Access with Incorrect Length Value
type: Class
subclass of: Improper Restriction of Operations within the Bounds of a Memory Buffer
cwe-id: CWE-805

Buffer Access Using Size of Source Buffer
type: Class
subclass of: Buffer Access with Incorrect Length Value
cwe-id: CWE-806

Reliance on Untrusted Inputs in a Security Decision
type: Class
subclass of: Protection Mechanism Failure
cwe-id: CWE-807

Improper Neutralization of Script in an Error Message Web Page
type: Class
subclass of: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
cwe-id: CWE-81

Improper Neutralization of Script in Attributes of IMG Tags in a Web Page
type: Class
subclass of: Improper Neutralization of Script in Attributes in a Web Page
cwe-id: CWE-82

Missing Synchronization
type: Class
subclass of: Improper Synchronization
cwe-id: CWE-820

Incorrect Synchronization
type: Class
subclass of: Improper Synchronization
cwe-id: CWE-821

Untrusted Pointer Dereference
type: Class
subclass of: Improper Restriction of Operations within the Bounds of a Memory Buffer
subclass of: Restriction
  on property: weakness-of
  some values from: Pointer Dereferencing Function
type: NamedIndividual
weakness-of: Pointer Dereferencing Function
cwe-id: CWE-822

Use of Out-of-range Pointer Offset
type: Class
subclass of: Improper Restriction of Operations within the Bounds of a Memory Buffer
cwe-id: CWE-823

Access of Uninitialized Pointer
type: Class
subclass of: Improper Restriction of Operations within the Bounds of a Memory Buffer
subclass of: Restriction
  on property: weakness-of
  some values from: Pointer Dereferencing Function
type: NamedIndividual
weakness-of: Pointer Dereferencing Function
cwe-id: CWE-824

Expired Pointer Dereference
type: Class
subclass of: Improper Restriction of Operations within the Bounds of a Memory Buffer
subclass of: Operation on a Resource after Expiration or Release
subclass of: Restriction
  on property: weakness-of
  some values from: User Input Function
type: NamedIndividual
weakness-of: User Input Function
cwe-id: CWE-825

Premature Release of Resource During Expected Lifetime
type: Class
subclass of: Operation on Resource in Wrong Phase of Lifetime
cwe-id: CWE-826

Improper Control of Document Type Definition
type: Class
subclass of: Use of Incorrectly-Resolved Name or Reference
subclass of: Inclusion of Functionality from Untrusted Control Sphere
cwe-id: CWE-827

Signal Handler with Functionality that is not Asynchronous-Safe
type: Class
subclass of: Signal Handler Race Condition
cwe-id: CWE-828

Inclusion of Functionality from Untrusted Control Sphere
type: Class
subclass of: Incorrect Resource Transfer Between Spheres
cwe-id: CWE-829

Improper Neutralization of Script in Attributes in a Web Page
type: Class
subclass of: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
cwe-id: CWE-83

Inclusion of Web Functionality from an Untrusted Source
type: Class
subclass of: Inclusion of Functionality from Untrusted Control Sphere
cwe-id: CWE-830

Signal Handler Function Associated with Multiple Signals
type: Class
subclass of: Signal Handler Race Condition
cwe-id: CWE-831

Unlock of a Resource that is not Locked
type: Class
subclass of: Improper Locking
cwe-id: CWE-832

Deadlock
type: Class
subclass of: Improper Locking
cwe-id: CWE-833

Excessive Iteration
type: Class
subclass of: Insufficient Control Flow Management
cwe-id: CWE-834

Loop with Unreachable Exit Condition ('Infinite Loop')
type: Class
subclass of: Excessive Iteration
cwe-id: CWE-835

Use of Password Hash Instead of Password for Authentication
type: Class
subclass of: Weak Authentication
cwe-id: CWE-836

Improper Enforcement of a Single, Unique Action
type: Class
subclass of: Improper Control of Interaction Frequency
cwe-id: CWE-837

Inappropriate Encoding for Output Context
type: Class
subclass of: Improper Encoding or Escaping of Output
cwe-id: CWE-838

Numeric Range Comparison Without Minimum Check
type: Class
subclass of: Incomplete Comparison with Missing Factors
cwe-id: CWE-839

Improper Neutralization of Encoded URI Schemes in a Web Page
type: Class
subclass of: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
cwe-id: CWE-84

Improper Enforcement of Behavioral Workflow
type: Class
subclass of: Insufficient Control Flow Management
cwe-id: CWE-841

Placement of User into Incorrect Group
type: Class
subclass of: Incorrect User Management
cwe-id: CWE-842

Access of Resource Using Incompatible Type ('Type Confusion')
type: Class
subclass of: Incorrect Type Conversion or Cast
cwe-id: CWE-843

Doubled Character XSS Manipulations
type: Class
subclass of: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
cwe-id: CWE-85

Improper Neutralization of Invalid Characters in Identifiers in Web Pages
type: Class
subclass of: Interpretation Conflict
subclass of: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
cwe-id: CWE-86

Missing Authorization
type: Class
subclass of: Improper Authorization
cwe-id: CWE-862
comment: Broad and could apply to all resource accesses.

Incorrect Authorization
type: Class
subclass of: Improper Authorization
cwe-id: CWE-863

Improper Neutralization of Alternate XSS Syntax
type: Class
subclass of: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
cwe-id: CWE-87

Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
type: Class
subclass of: Improper Neutralization of Special Elements used in a Command ('Command Injection')
cwe-id: CWE-88

Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
type: Class
subclass of: Improper Neutralization of Special Elements in Data Query Logic
subclass of: Restriction
  on property: weakness-of
  some values from: User Input Function
type: NamedIndividual
weakness-of: User Input Function
cwe-id: CWE-89

J2EE Misconfiguration: Weak Access Permissions for EJB Methods
type: Class
subclass of: Incorrect Privilege Assignment
cwe-id: CWE-9

Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection')
type: Class
subclass of: Improper Neutralization of Special Elements in Data Query Logic
cwe-id: CWE-90

Use of Uninitialized Resource
type: Class
subclass of: Improper Initialization
cwe-id: CWE-908

Missing Initialization of Resource
type: Class
subclass of: Improper Initialization
cwe-id: CWE-909

XML Injection (aka Blind XPath Injection)
type: Class
subclass of: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
cwe-id: CWE-91

Use of Expired File Descriptor
type: Class
subclass of: Operation on a Resource after Expiration or Release
cwe-id: CWE-910

Improper Update of Reference Count
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-911

Hidden Functionality
type: Class
subclass of: Incorrect Provision of Specified Functionality
cwe-id: CWE-912

Improper Control of Dynamically-Managed Code Resources
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-913

Improper Control of Dynamically-Identified Variables
type: Class
subclass of: Improper Control of Dynamically-Managed Code Resources
subclass of: Improper Control of Resource Identifiers ('Resource Injection')
cwe-id: CWE-914

Improperly Controlled Modification of Dynamically-Determined Object Attributes
type: Class
subclass of: Improper Control of Dynamically-Managed Code Resources
cwe-id: CWE-915

Use of Password Hash With Insufficient Computational Effort
type: Class
subclass of: Use of a Broken or Risky Cryptographic Algorithm
cwe-id: CWE-916

Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')
type: Class
subclass of: Improper Neutralization of Special Elements used in a Command ('Command Injection')
cwe-id: CWE-917

Server-Side Request Forgery (SSRF)
type: Class
subclass of: Unintended Proxy or Intermediary ('Confused Deputy')
subclass of: Restriction
  on property: weakness-of
  some values from: User Input Function
type: NamedIndividual
weakness-of: User Input Function
cwe-id: CWE-918

Improper Restriction of Power Consumption
type: Class
subclass of: Uncontrolled Resource Consumption
cwe-id: CWE-920

Storage of Sensitive Data in a Mechanism without Access Control
type: Class
subclass of: Insecure Storage of Sensitive Information
cwe-id: CWE-921

Insecure Storage of Sensitive Information
type: Class
subclass of: Improper Control of a Resource Through its Lifetime
cwe-id: CWE-922

Improper Restriction of Communication Channel to Intended Endpoints
type: Class
subclass of: Improper Access Control
cwe-id: CWE-923

Improper Enforcement of Message Integrity During Transmission in a Communication Channel
type: Class
subclass of: Insufficient Verification of Data Authenticity
cwe-id: CWE-924

Improper Verification of Intent by Broadcast Receiver
type: Class
subclass of: Improper Verification of Source of a Communication Channel
cwe-id: CWE-925

Improper Export of Android Application Components
type: Class
subclass of: Improper Authorization
cwe-id: CWE-926

Use of Implicit Intent for Sensitive Communication
type: Class
subclass of: Improper Authorization
subclass of: Exposure of Resource to Wrong Sphere
cwe-id: CWE-927

Improper Neutralization of CRLF Sequences ('CRLF Injection')
type: Class
subclass of: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
cwe-id: CWE-93

Improper Authorization in Handler for Custom URL Scheme
type: Class
subclass of: Missing Authorization
cwe-id: CWE-939

Improper Control of Generation of Code ('Code Injection')
type: Class
subclass of: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
subclass of: Improper Control of Dynamically-Managed Code Resources
subclass of: Restriction
  on property: may-be-weakness-of
  some values from: Eval Function
subclass of: Restriction
  on property: may-be-weakness-of
  some values from: User Input Function
type: NamedIndividual
may-be-weakness-of: Eval Function
may-be-weakness-of: User Input Function
cwe-id: CWE-94

Improper Verification of Source of a Communication Channel
type: Class
subclass of: Improper Restriction of Communication Channel to Intended Endpoints
cwe-id: CWE-940

Incorrectly Specified Destination in a Communication Channel
type: Class
subclass of: Improper Restriction of Communication Channel to Intended Endpoints
cwe-id: CWE-941

Permissive Cross-domain Policy with Untrusted Domains
type: Class
subclass of: Permissive List of Allowed Inputs
subclass of: Improper Restriction of Communication Channel to Intended Endpoints
cwe-id: CWE-942

Improper Neutralization of Special Elements in Data Query Logic
type: Class
subclass of: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
cwe-id: CWE-943

Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')
type: Class
subclass of: Improper Control of Generation of Code ('Code Injection')
cwe-id: CWE-95

Improper Neutralization of Directives in Statically Saved Code ('Static Code Injection')
type: Class
subclass of: Improper Control of Generation of Code ('Code Injection')
cwe-id: CWE-96

Improper Neutralization of Server-Side Includes (SSI) Within a Web Page
type: Class
subclass of: Improper Neutralization of Directives in Statically Saved Code ('Static Code Injection')
cwe-id: CWE-97

Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion')
type: Class
subclass of: Use of Incorrectly-Resolved Name or Reference
subclass of: Inclusion of Functionality from Untrusted Control Sphere
cwe-id: CWE-98

Improper Control of Resource Identifiers ('Resource Injection')
type: Class
subclass of: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
cwe-id: CWE-99

Processor Cache Memory
type: Class
subclass of: Primary Storage
subclass of: Restriction
  on property: accessed-by
  some values from: Central Processing Unit
subclass of: Restriction
  on property: may-contain
  some values from: Process Segment
subclass of: Restriction
  on property: modifies
  some values from: Processor Cache Memory
type: NamedIndividual
accessed-by: Central Processing Unit
may-contain: Process Segment
definition: Cache memory is temporary storage that is more readily available to the processor than the computer's main memory source, located between the main memory and the processor. It is typically either integrated directly into the CPU chip (level 1 cache) or placed on a separate chip with a bus interconnect with the CPU (level 2 cache).

Call Stack
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: contains
  some values from: Stack Frame
type: NamedIndividual
contains: Stack Frame
definition: In computer science, a call stack is a stack data structure that stores information about the active subroutines of a computer program. This kind of stack is also known as an execution stack, program stack, control stack, run-time stack, or machine stack, and is often shortened to just "the stack". Although maintenance of the call stack is important for the proper functioning of most software, the details are normally hidden and automatic in high-level programming languages. Many computer instruction sets provide special instructions for manipulating stacks.

Canopy Clustering
type: Class
subclass of: Cluster Analysis
type: NamedIndividual
d3fend-id: D3A-CC
definition: The canopy clustering algorithm is an unsupervised pre-clustering algorithm often used as preprocessing step for the K-means algorithm or the Hierarchical clustering algorithm. It is intended to speed up clustering operations on large data sets.
kb-article: ## References Wikipedia. (n.d.). Canopy clustering algorithm. [Link](https://en.wikipedia.org/wiki/Canopy_clustering_algorithm)

Capability
type: Class
subclass of: External Thing

Central Processing Unit
type: Class
subclass of: Processor
subclass of: Restriction
  on property: contains
  some values from: Processor Register
subclass of: Restriction
  on property: may-contain
  some values from: Processor Cache Memory
subclass of: Restriction
  on property: may-contain
  some values from: Memory Management Unit
subclass of: Restriction
  on property: may-contain
  some values from: Memory Protection Unit
type: NamedIndividual
contains: Processor Register
may-contain: Processor Cache Memory
may-contain: Memory Management Unit
may-contain: Memory Protection Unit
definition: A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, and input/output (I/O) operations specified by the instructions in the program. This contrasts with external components such as main memory and I/O circuitry, and specialized processors such as graphics
synonym: CPU
synonym: Central Processor
synonym: Main Processor

Central Tendency
type: Class
subclass of: Descriptive Statistics
type: NamedIndividual
d3fend-id: D3A-CT
definition: A measure of central tendency ) is a summary measure that attempts to describe a whole set of data with a single value that represents the middle or centre of its distribution.
kb-article: ## References Australian Bureau of Statistics. (n.d.). Measures of Central Tendency. [Link](https://www.abs.gov.au/statistics/understanding-statistics/statistical-terms-and-concepts/measures-central-tendency) Wikipedia. (n.d.). Central tendency. [Link](https://en.wikipedia.org/wiki/Central_tendency)

Centroid-based Clustering
type: Class
subclass of: Cluster Analysis
type: NamedIndividual
d3fend-id: D3A-CBC
definition: Centroid-based clustering organizes the data into non-hierarchical clusters, in contrast to hierarchical clustering defined below. K-means is the most widely-used centroid-based clustering algorithm. Centroid-based algorithms are efficient but sensitive to initial conditions and outliers.
kb-article: ## References Google Developers. (n.d.). Clustering Algorithms. [Link](https://developers.google.com/machine-learning/clustering/clustering-algorithms)

Certificate
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: contains
  some values from: Identifier
subclass of: Restriction
  on property: contains
  some values from: Public Key
type: NamedIndividual
contains: Identifier
contains: Public Key
definition: In cryptography, a public key certificate, also known as a digital certificate or identity certificate, is an electronic document used to prove the ownership of a public key. The certificate includes information about the key, information about the identity of its owner (called the subject), and the digital signature of an entity that has verified the certificate's contents (called the issuer). If the signature is valid, and the software examining the certificate trusts the issuer, then it can use that key to communicate securely with the certificate's subject. In email encryption, code signing, and e-signature systems, a certificate's subject is typically a person or organization. However, in Transport Layer Security (TLS) a certificate's subject is typically a computer or other device.
alternative label: Public Key Certificate

Certificate-based Authentication
type: Class
subclass of: Agent Authentication
subclass of: Restriction
  on property: reads
  some values from: Certificate
type: NamedIndividual
kb-reference: Reference-FederalPublicKeyInfrastructure101
reads: Certificate
d3fend-id: D3-CBAN
definition: Requiring a digital certificate in order to authenticate a user.
kb-article: ## How it works Certificate-based authentication is a security mechanism that uses digital certificates to verify the identity of a user, device, or server before granting access to a network or system. This method relies on a pair of cryptographic keys: a public key and a private key. ## Considerations * Private Key Protection: Ensure that private keys are securely stored and protected against unauthorized access. * Certificate Revocation: Implement a robust process for revoking certificates if they are compromised or no longer needed. * Man-in-the Middle Attacks: Use mutual authentication to mitigate the risk of these attacks.

Certificate Analysis
type: Class
subclass of: Network Traffic Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Certificate File
type: NamedIndividual
analyzes: Certificate File
kb-reference: Reference-SecuringWebTransactions
d3fend-id: D3-CA
definition: Analyzing Public Key Infrastructure certificates to detect if they have been misconfigured or spoofed using both network traffic, certificate fields and third-party logs.
kb-article: ## How it works Certificate Analysis ensures that the data elements of the certificate are current and anchored in a known trust model. Certificate authorities, revocation lists, and third-party secure logs are used in the analysis. Analysis includes detection of server impersonation, phishing domains, and forged certificates. TLS certificates are designed to expire to ensure that the cryptographic keys are forced to be changed on a regular basis. The certificates in the trust path also expire and can cause a break in the trust chain. This means that even if a server certificate is updated correctly, intermediate certificates can expire and the trust chain is not maintained. This can cause services to become unavailable.

Certificate File
type: Class
subclass of: File
subclass of: Restriction
  on property: contains
  some values from: Certificate
type: NamedIndividual
contains: Certificate
definition: A file containing a digital certificate. In cryptography, a public key certificate (also known as a digital certificate or identity certificate) is an electronic document used to prove the ownership of a public key. The certificate includes information about the key, information about its owner's identity, and the digital signature of an entity that has verified the certificate's contents are correct. If the signature is valid, and the person examining the certificate trusts the signer, then they know they can use that key to communicate with its owner.

Certificate Pinning
type: Class
subclass of: Credential Hardening
subclass of: Restriction
  on property: authenticates
  some values from: Public Key
subclass of: Restriction
  on property: hardens
  some values from: Certificate
type: NamedIndividual
authenticates: Public Key
hardens: Certificate
kb-reference: Reference-CertificateAndPublicKeyPinning
kb-reference: Reference-End-to-endCertificatePinning
kb-reference: Reference-PublicKeyPinningExtensionForHTTP
d3fend-id: D3-CP
definition: Persisting either a server's X.509 certificate or their public key and comparing that to server's presented identity to allow for greater client confidence in the remote server's identity for SSL connections.
kb-article: ## How it works Pinning allows for a trusted copy of a certificate or public key to be associated with a server and thus reducing the likelihood of frequently visited sites being subjected to man-in-the-middle attacks. Certificates or public keys can be pinned after a trusted connection has been established or the pinning can be preloaded in an application, which is the preferred method for mobile applications. Pinning can take the form of certificate pinning or public key pinning. ## Forms of Pinning * Certificate Pinning (CP) allows for the client to verify the X.509 certificate with a preloaded certificate. Typically, this is involves storing a hash of the certificate and using the stored hash for comparison to the hash of the certificate submitted during the SSL handshake. * Public Key Pinning (PKP) requires the extraction of a public key from server's certificate. The stored public key is compared to the server's presented public key. A public key is expected to rotate less frequently than an X.509 certificate and is generally favored over certificate pinning. An extension of PKP is Subject Public Key Information Pinning (SPKI) includes public key pinning plus additional information for SSL connections. The additional information can include preferred algorithms. ## Considerations * With pinned certificates whenever a server updates its certificate, the pinned certificates will also need to be updated * With pinned public keys the extracted key may be subject to key refresh policies but much less frequently * Servers can become unavailable if pinned objects are set and not updated with the rotated identities. This may require a pinning strategy to be developed. * The application of this technique within web browser applications has been [deprecated](https://developer.mozilla.org/en-US/docs/Web/HTTP/Public_Key_Pinning) by popular web browser developers. They now favor certificate analysis via public certificate transparency logs, and the EXPECT-CT HTTP header.

Certificate Rotation
type: Class
subclass of: Credential Rotation
subclass of: Restriction
  on property: regenerates
  some values from: Certificate
type: NamedIndividual
regenerates: Certificate
d3fend-id: D3-CERO
definition: Certificate rotation involves replacing digital certificates and their private keys to maintain cryptographic integrity and trust, mitigating key compromise risks and ensuring continuous secure communications.
kb-article: Reference-PasswordandKeyRotation-SSH
kb-article: ## How it works Certificate rotation should be performed when: - Any certificate expires. - A new CA authority is substituted for the old, thus requiring a replacement root certificate. - New or modified constraints need to be imposed on one or more certificates. - A security breach has occurred. Considerations: - Managing certificate rotation across an enterprise can be complex. Automated solutions, sold by multiple vendors, should be considered to manage this complexity.

Certificate Trust Store
type: Class
subclass of: Trust Store
subclass of: Restriction
  on property: contains
  some values from: Certificate
type: NamedIndividual
contains: Certificate
definition: A certificate truststore is used to store public certificates used to authenticate clients by the server for an SSL connection.

Chatroom Client
type: Class
subclass of: Collaborative Software
definition: Client software used to describe conduct any form of synchronous conferencing, occasionally even asynchronous conferencing. The term can thus mean any technology ranging from real-time online chat and online interaction with strangers (e.g., online forums) to fully immersive graphical social environments.
alternative label: Chat Room Client

Child Process
type: Class
subclass of: Process
definition: A child process in computing is a process created by another process (the parent process). This technique pertains to multitasking operating systems, and is sometimes called a subprocess or traditionally a subtask. There are two major procedures for creating a child process: the fork system call (preferred in Unix-like systems and the POSIX standard) and the spawn (preferred in the modern (NT) kernel of Microsoft Windows, as well as in some historical operating systems).

Classification
type: Class
subclass of: Supervised Learning
type: NamedIndividual
d3fend-id: D3A-CLA
definition: Classification uses an algorithm to accurately assign test data into specific categories.
kb-article: ## How it works Classification recognizes specific entities within the dataset and attempts to draw some conclusions on how those entities should be labeled or defined. Common classification algorithms are linear classifiers, support vector machines (SVM), decision trees, k-nearest neighbor, and random forest, which are described in more detail below. ## Considerations: There are many different types of classification algorithms for modeling classification predictive modeling problems. There is no single theory on how to map algorithms onto problem types; instead, it is generally recommended that a practitioner use controlled experiments and discover which algorithm and algorithm configuration results in the best performance for a given classification task. ## Key Test Considerations - **Machine Learning**: - **Verify the dataset quality**: Check the data to make sure it is free of errors. Quantify the degree of missing values, outliers, and noise in the data collection. If the data quality is low, it may be difficult or impossible to create models and systems with the desired performance. - **Verify development datasets are representative** of expected operational environment and data collection means. Compare distributions of dataset features and labels with exploratory data analysis and assess the difference in tests on training data and tests on evaluation data (where the evaluation data must be drawn from a representative dataset.) - **Use software libraries**: and tools built for ML where possible, so that the underlying code is verified by prior use.** - **Diagnose model errors with domain SMEs**: Have problem domain SMEs investigate model errors for conditions for which the model may underperform and suggest refinements. - **Classification**: - **Use Standard Classification Performance Measures**: Not all of the following may be necessary, but should be considered for both verification (developmental test) and operational test stages use: - **Accuracy**: The…

Classifying
type: Class
subclass of: Analytical Purpose

Client-server Payload Profiling
type: Class
subclass of: Network Traffic Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Network Traffic
type: NamedIndividual
analyzes: Network Traffic
kb-reference: Reference-MethodAndSystemForDetectingMaliciousPayloads VectraNetworksInc
d3fend-id: D3-CSPP
definition: Comparing client-server request and response payloads to a baseline profile to identify outliers.
kb-article: ## How it works Profiling request and response payloads across multiple clients to a single server to develop a baseline of their characteristics. May take into account request/response sizes, entropy, frequency, and rhythm. Finally, identify outliers as they may indicate a malicious payload delivery and subsequent server exploitation. ## Considerations * Collecting metrics to establish a profile can be challenging since user behavior can change easily. * Employees may work different hours or inconsistent schedules which will cause false positives. * Collection of network activity to generate metrics is a computationally intensive process. * Users may log into different workstations which may cause false positives.

Client Application
type: Class
subclass of: Application
type: NamedIndividual
definition: A client application is software that accesses a service made available by a server. The server is often (but not always) on another computer system, in which case the client accesses the service by way of a network. The term applies to the role that programs or devices play in the client-server model

Client Computer
type: Class
subclass of: Host
definition: A client computer is a host that accesses a service made available by a server. The server is often (but not always) on another computer system, in which case the client accesses the service by way of a network.

Clipboard
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: The clipboard is a buffer that some operating systems provide for short-term storage and transfer within and between application programs. The clipboard is usually temporary and unnamed, and its contents reside in the computer's RAM. The clipboard is sometimes called the paste buffer. Windows, Linux and macOS support a single clipboard transaction. Each cut or copy overwrites the previous contents. Normally, paste operations copy the contents, leaving the contents available in the clipboard for further pasting.

Cloud Configuration
type: Class
subclass of: Configuration Resource
type: NamedIndividual
definition: Information used to configure the services, parameters, and initial settings for a virtual server instance running in a cloud service.
alternative label: Cloud Configuration Information

Cloud Instance Metadata
type: Class
subclass of: Cloud Configuration
type: NamedIndividual
definition: Cloud instance metadata is configuration information on the instance and users of the instance. This includes such information as security groups, public ip addresses, and private addresses, public keys configured, and event rotating security keys. User data can contain initialization scripts, variables, passwords, and more.

Cloud Service Authentication
type: Class
subclass of: Web Authentication
type: NamedIndividual
definition: A request-response comprising a user credential presentation to a system and a verification response where the verifying party is a cloud service.

Cloud Service Authorization
type: Class
subclass of: Authorization
type: NamedIndividual
definition: Cloud authorization is the function of specifying access rights to cloud resources.

Cloud Service Provider
type: Class
subclass of: Service Provider
definition: A cloud service provider delivers scalable and distributed computing resources over a network, enabling clients to access infrastructure, platforms, and applications remotely.

Cloud Service Sensor
type: Class
subclass of: Cyber Sensor
subclass of: Restriction
  on property: monitors
  some values from: Cloud Service Authentication
subclass of: Restriction
  on property: monitors
  some values from: Cloud Service Authorization
type: NamedIndividual
monitors: Cloud Service Authentication
monitors: Cloud Service Authorization
definition: Senses data from cloud service platforms. Including data from cloud service authentications, authorizations, and other activities.

Cloud Storage
type: Class
subclass of: Secondary Storage
type: NamedIndividual
definition: Cloud storage is storage held within a computing cloud.

Cloud User Account
type: Class
subclass of: User Account
type: NamedIndividual
definition: A user account on a given host is a local user account for a given cloud and specified resources within that cloud.

Cluster Analysis
type: Class
subclass of: Unsupervised Learning
type: NamedIndividual
d3fend-id: D3A-CA
definition: Cluster analysis or clustering is the task of grouping a set of objects in such a way that objects in the same group (called a cluster) are more similar (in some sense) to each other than to those in other groups (clusters).
kb-article: ## References Cluster analysis. (n.d.). Wikipedia. [Link](https://en.wikipedia.org/wiki/Cluster_analysis)

Clustering
type: Class
subclass of: Summarizing

Code Analyzer
type: Class
subclass of: Developer Application
type: NamedIndividual
definition: Code analyzers automatically analyze the composition or behavior of computer programs regarding a property such as correctness, robustness, security, and safety. Program analysis can be performed without executing the program (static program analysis), during runtime (dynamic program analysis) or in a combination of both.
alternative label: Program Analysis Tool

Code Repository
type: Class
subclass of: Database
type: NamedIndividual
definition: A code repository is a form of database where code, typically source code, is stored and managed. In revision control systems, a repository is a data structure that stores metadata for a set of files or directory structure. Depending on whether the version control system in use is distributed like (Git or Mercurial) or centralized like (Subversion, CVS, or Perforce), the whole set of information in the repository may be duplicated on every user's system or may be maintained on a single server.
alternative label: Repository
alternative label: Version Control Repository

Coefficient of Variation
type: Class
subclass of: Variability
type: NamedIndividual
d3fend-id: D3A-COV
definition: The coefficient of variation (CV), also known as relative standard deviation (RSD), is a standardized measure of dispersion of a probability distribution or frequency distribution. The coefficient of variation (CV) is defined as the ratio of the standard deviation to the mean .
kb-article: ## References Wikipedia. (n.d.). Coefficient of variation. [Link](https://en.wikipedia.org/wiki/Coefficient_of_variation)
synonym: RSD
synonym: Relative Standard Deviation

Collaborative Software
type: Class
subclass of: User Application
definition: Collaborative software or groupware is application software designed to help people working on a common task to attain their goals. One of the earliest definitions of groupware is "intentional group processes plus software to support them". Collaborative software is a broad concept that overlaps considerably with computer-supported cooperative work (CSCW). According to Carstensen and Schmidt (1999) groupware is part of CSCW. The authors claim that CSCW, and thereby groupware, addresses "how collaborative activities and their coordination can be supported by means of computer systems."

Collection Technique
type: Class
subclass of: ATTACK Enterprise Technique
subclass of: Offensive Technique
subclass of: Restriction
  on property: enables
  some values from: Collection
type: NamedIndividual
enables: Collection

Network Agent
type: Class
subclass of: Software
type: NamedIndividual
definition: A network agent is software installed on a network node or device that transmits information back to a collector agent or management system. Kinds of network agents include SNMP Agent, IPMI agents, WBEM agents, and many proprietary agents capturing network monitoring and management information.
synonym: Exporter

Command
type: Class
subclass of: Digital Information
type: NamedIndividual
definition: In computing, a command is a directive to a computer program acting as an interpreter of some kind, in order to perform a specific task. Most commonly a command is either a directive to some kind of command-line interface, such as a shell, or an event in a graphical user interface triggered by the user selecting an option in a menu.

Command and Control Technique
type: Class
subclass of: ATTACK Enterprise Technique
subclass of: Offensive Technique
subclass of: Restriction
  on property: enables
  some values from: Command And Control
type: NamedIndividual
enables: Command And Control

Command History Log
type: Class
subclass of: Event Log
type: NamedIndividual
definition: A log of commands run in an operating system shell.

Command History Log File
type: Class
subclass of: Log File
subclass of: Restriction
  on property: contains
  some values from: Command History Log
type: NamedIndividual
contains: Command History Log
definition: A command history log file is a file containing a command history, which the history of commands run in an operating system shell.

Command Line Interface
type: Class
subclass of: User Interface
definition: A command-line interface or command language interpreter (CLI), also known as command-line user interface, console user interface, and character user interface (CUI), is a means of interacting with a computer program where the user (or client) issues commands to the program in the form of successive lines of text (command lines). Command-line interfaces to computer operating systems are less widely used by casual computer users, who favor graphical user interfaces. Programs with command-line interfaces are generally easier to automate via scripting.
alternative label: CLI
alternative label: CUI
alternative label: Command-line Interface

Common Attack Pattern
type: Class
subclass of: CAPEC Thing
definition: A common attack pattern that is in the CAPEC knowledge base.

Compiler
type: Class
subclass of: Build Tool
subclass of: Restriction
  on property: reads
  some values from: Compiler Configuration File
type: NamedIndividual
reads: Compiler Configuration File
definition: In computing, a compiler is a computer program that translates computer code written in one programming language (the source language) into another language (the target language). The name "compiler" is primarily used for programs that translate source code from a high-level programming language to a lower level language (e.g., assembly language, object code, or machine code) to create an executable program.

Compiler Configuration File
type: Class
subclass of: Application Configuration File
type: NamedIndividual
definition: A file containing Information used to configure the parameters and initial settings for a compiler.

Compute Device Event
type: Class
subclass of: Hardware Device Event
subclass of: Restriction
  on property: has-participant
  some values from: Processor
definition: An event capturing the operation, state, or performance of computational hardware, such as CPUs, GPUs, or accelerators. These events reflect processing capacity changes, utilization anomalies, or device health.

Computer Network Node
type: Class
subclass of: Computer Platform
subclass of: Network Node
definition: A network node running on a computer platform.

Computer Platform
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: contains
  some values from: Firmware
subclass of: Restriction
  on property: contains
  some values from: Hardware Device
subclass of: Restriction
  on property: contains
  some values from: Operating System
type: NamedIndividual
contains: Firmware
contains: Hardware Device
contains: Operating System
definition: Platform includes the hardware and OS. The term computing platform can refer to different abstraction levels, including a certain hardware architecture, an operating system (OS), and runtime libraries. In total it can be said to be the stage on which computer programs can run.
synonym: Computing Platform

Computing Image
type: Class
subclass of: Digital Information Bearer
definition: A computing image captures the full state or contents of a computing entity, such as a process or volume.

Computing Server
type: Class
subclass of: Server
definition: A compute server is a system specifically designed to undertake large amounts of computation, usually but not necessarily in a client/server environment.

Computing Snapshot
type: Class
subclass of: Digital Information Bearer
definition: In computer systems, a snapshot is the state of a system at a particular point in time.
alternative label: Snapshot

Condition
type: Class
subclass of: D3FEND Core
definition: An assumption on which rests the validity or effect of something else.
comment: Less common usage versus state, meant to superclass precondition, postcondition, and effect.

Configuration Database
type: Class
subclass of: Configuration Resource
subclass of: Restriction
  on property: contains
  some values from: Configuration Database Record
type: NamedIndividual
contains: Configuration Database Record

Configuration Database Record
type: Class
subclass of: Configuration Resource
subclass of: Record
type: NamedIndividual
synonym: Configuration Record

Configuration File
type: Class
subclass of: File
definition: A file containing Information used to configure the parameters and initial settings for some computer programs. They are used for user applications, server processes and operating system settings.
alternative label: Settings File

Configuration Inventory
type: Class
subclass of: Asset Inventory
subclass of: Restriction
  on property: inventories
  some values from: Configuration Resource
type: NamedIndividual
inventories: Configuration Resource
kb-reference: Reference-Web-BasedEnterpriseManagement
kb-reference: Reference-Windows-Management-Infrastructure
kb-reference: Reference-Windows-Management-Instrumentation
d3fend-id: D3-CI
definition: Configuration inventory identifies and records the configuration of software and hardware and their components throughout the organization.
kb-article: ## How it works The organization retrieves configuration information through means of SNMP (MIB records), WBEM (CIM records), other protocols, or custom scripts and captures that information in a repository, typically known as a Configuration Management Database (CMDB)."

Configuration Management Database
type: Class
subclass of: Configuration Database
definition: A database used to store configuration records throughout their lifecycle. The Configuration Management System (CMS) maintains one or more CMDBs, and each CMDB stores attributes of configuration items (CIs), and relationships with other CIs.

Configuration Resource
type: Class
subclass of: Resource
type: NamedIndividual
definition: A resource used to configure a system including software and hardware.

Connect Socket
type: Class
subclass of: System Call
subclass of: Restriction
  on property: connects
  some values from: Pipe
type: NamedIndividual
connects: Pipe
definition: The connect socket system call connects the socket to a target address.

Connected Honeynet
type: Class
subclass of: Decoy Environment
subclass of: Restriction
  on property: spoofs
  some values from: Local Area Network
type: NamedIndividual
kb-reference: Reference-ModificationOfAServerToMimicADeceptionMechanism AcalvioTechnologiesInc
spoofs: Local Area Network
d3fend-id: D3-CHN
definition: A decoy service, system, or environment, that is connected to the enterprise network, and simulates or emulates certain functionality to the network, without exposing full access to a production system.
kb-article: ## How it works Decoy honeypots are deployed within the enterprise environment that emulate certain services or portions of an OS to attract attackers. ## Considerations A connected honeynet provides a tradeoff between emulating certain functionality but not being as sophisticated as an integrated honeynet. The connected honeynet may not provide enough functionality to detect new attack patterns or zero day exploits but could provide enough functionality for specific known vulnerabilities.

Connection Attempt Analysis
type: Class
subclass of: Network Traffic Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Intranet Network Traffic
type: NamedIndividual
analyzes: Intranet Network Traffic
kb-reference: Reference-DetectingNetworkReconnaissanceByTrackingIntranetDark-netCommunications VECTRANETWORKSInc
d3fend-id: D3-CAA
definition: Analyzing failed connections in a network to detect unauthorized activity.
kb-article: ## How it works Connection Attempt Analysis in multiple ways. ### Monitoring traffic to unallocated IP space One approach looks for failed connection attempts against unallocated IP space. First, network traffic is captured to map out the network to identify network assets as well as unallocated IP space. The map is then used to determine if connection attempts are being made to the unallocated IP space. ### Monitoring for sequentially transmitted traffic Another approach passively inspects network traffic with application protocol analyzers observing network activity characteristics such as volume of packets sent/ received, TCP session attributes, and connection information between hosts (start time, source/destination host, services, etc.). Then using pattern matching to identify traffic which appears to be probing for network hosts. ## Considerations * Implementations that rely on analysis of unallocated IP address space increase in their complexity with network size and decentralized network infrastructure. * Inventory of unallocated IP space should should be continuously updated to mitigate the risk of false positives. * IPv6 also introduces challenges including IPv6 traffic bypassing IPv4 specific protection systems (ex. firewalls and IDS) and complexity in managing both IPv6 and IPv4 addresses.
synonym: Network Scan Detection

Console Output Function
type: Class
subclass of: Subroutine
definition: Outputs characters to a computer console.

Container Build Tool
type: Class
subclass of: Software Packaging Tool
definition: A software build tool that creates a container (e.g., Docker container) for deployment.

Container Image
type: Class
subclass of: Computing Image
subclass of: Software Package
type: NamedIndividual
definition: A container is a standard unit of software that packages up code and all its dependencies so the application runs quickly and reliably from one computing environment to another. A Docker container image is a lightweight, standalone, executable package of software that includes everything needed to run an application: code, runtime, system tools, system libraries and settings. :S Container images become containers at runtime and in the case of Docker containers - images become containers when they run on Docker Engine. Available for both Linux and Windows-based applications, containerized software will always run the same, regardless of the infrastructure. Containers isolate software from its environment and ensure that it works uniformly despite differences for instance between development and staging.

Container Image Analysis
type: Class
subclass of: Asset Vulnerability Enumeration
subclass of: Restriction
  on property: analyzes
  some values from: Container Image
type: NamedIndividual
analyzes: Container Image
kb-reference: Reference-ContainerImageAnalysis
d3fend-id: D3-CIA
definition: Analyzing a Container Image with respect to a set of policies.
kb-article: ## How it works Container images are standalone collections of the executable code and content that are used to populate a container environment. They are usually created by either building a container from scratch or by building on top of an existing image pulled from a repository. Throughout the container build workflow, images should be scanned to identify: - outdated libraries, - known vulnerabilities, - or misconfigurations, such as insecure ports or permissions. Scanning should also provide the flexibility to disregard false positives for vulnerability detection where knowledgeable cybersecurity professionals have deemed alerts to be inaccurate. One approach to implementing image scanning is to use an admission controller to block deployments if the image does not comply with the organization's security policies. An admission controller is a Container Orchestration feature that can intercept and process requests to the Container Orchestration API prior to persistence of the object, but after the request is authenticated and authorized. A webhook can be implemented to scan any image before it is deployed in the orchestrator. This admission controller ## Considerations * Image scanning is key to ensuring deployed containers are secure. * Using trusted repositories to build containers is a critical part of the container build workflow. * This technique does not necessarly prevent the build process to add insecure or unsecured files to the Image.
synonym: Container Image Scanning

Container Orchestration Software
type: Class
subclass of: Service Application
type: NamedIndividual
definition: A d3f:Software which manages and coordinates running one or more d3f:ContainerProcess.

Container Process
type: Class
subclass of: Application Process
definition: A running instance of a d3f:ContainerImage

Container Runtime
type: Class
subclass of: Service Application
subclass of: Restriction
  on property: runs
  some values from: Container Image
type: NamedIndividual
runs: Container Image
definition: A software layer between d3f:ContainerProcess and d3f:Kernel which often mediates the invocation of d3f:SystemCall

Control Catalog
type: Class
subclass of: External Control Thing
subclass of: Restriction
  on property: has-member
  some values from: External Control
subclass of: Restriction
  on property: version
  some values from: Datatype
    union of: integer
    union of: string
definition: A control catalog is a complete list of protective measures for systems, organizations, or individuals for subject domains (e.g., security and privacy.)

Control Correlation Identifier Catalog
type: Class
subclass of: Control Catalog
subclass of: Restriction
  on property: has-member
  some values from: CCI Control
definition: A control correlation identifier (CCI) catalog provides a catalog of CCIs for a given release date.

Convolutional Neural Network
type: Class
subclass of: Deep Neural Network Classification
type: NamedIndividual
d3fend-id: D3A-CNN
definition: A class of artificial neural network most commonly applied to analyze visual imagery.CNNs use a mathematical operation called convolution in place of general matrix multiplication in at least one of their layers.
kb-article: ## References Wikipedia. (n.d.). Convolutional neural network. [Link](https://en.wikipedia.org/wiki/Convolutional_neural_network)

Copy Memory Function
type: Class
subclass of: Subroutine
subclass of: Restriction
  on property: copies
  some values from: Memory Block
type: NamedIndividual
copies: Memory Block
definition: Copies a memory block from one location to another.

Copy Token
type: Class
subclass of: System Call
subclass of: Restriction
  on property: copies
  some values from: Access Token
type: NamedIndividual
type: System Call
copies: Access Token

Correlation
type: Class
subclass of: Descriptive Statistics
type: NamedIndividual
d3fend-id: D3A-COR
definition: Correlation is the degree to which two or more quantities are linearly associated.
kb-article: Wolfram MathWorld. (n.d.). Correlation. [Link](https://mathworld.wolfram.com/Correlation.html)

Correlation Clustering
type: Class
subclass of: High-dimension Clustering
type: NamedIndividual
d3fend-id: D3A-CC
definition: Correlation clustering provides a method for clustering a set of objects into the optimum number of clusters without specifying that number in advance.
kb-article: ## References Wikipedia. (n.d.). Correlation clustering. [Link](https://en.wikipedia.org/wiki/Correlation_clustering)

Cramer's V
type: Class
subclass of: Correlation
type: NamedIndividual
d3fend-id: D3A-CV
definition: Cramér's V (sometimes referred to as Cramér's phi and denoted as φc) is a measure of association between two nominal variables, giving a value between 0 and +1 (inclusive) and is based on Pearson's chi-squared statistic.
kb-article: ## References Wikipedia. (n.d.). Cramér's V. [Link](https://en.wikipedia.org/wiki/Cram%C3%A9r%27s_V)
synonym: Cramer's Phi

Create File
type: Class
subclass of: System Call
subclass of: Restriction
  on property: creates
  some values from: File
type: NamedIndividual
creates: File
definition: System call to create a new file on a file system. Some operating systems implement this functionality as part of their d3f:OpenFile system call.

Create Process
type: Class
subclass of: System Call
subclass of: Restriction
  on property: executes
  some values from: Process
type: NamedIndividual
executes: Process
definition: A process spawn refers to a function that loads and executes a new child process.The current process may wait for the child to terminate or may continue to execute asynchronously. Creating a new subprocess requires enough memory in which both the child process and the current program can execute. There is a family of spawn functions in DOS, inherited by Microsoft Windows. There is also a different family of spawn functions in an optional extension of the POSIX standards. Fork-exec is another technique combining two Unix system calls, which can effect a process spawn.
definition: Creates a process.
definition: Executes a process.
alternative label: Execute Process
alternative label: Process Spawn
alternative label: Spawn Process

Create Socket
type: Class
subclass of: System Call
subclass of: Restriction
  on property: creates
  some values from: Pipe
type: NamedIndividual
creates: Pipe
definition: A create socket system call creates an endpoint for communication and returns a file descriptor that refers to that endpoint.

Create Thread
type: Class
subclass of: System Call
subclass of: Restriction
  on property: creates
  some values from: Thread
type: NamedIndividual
creates: Thread
definition: Threads are an execution model that exists independently from a language, as well as a parallel execution model. They enable a program to control multiple different flows of work that overlap in time.

Credential
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: authenticates
  some values from: User Account
type: NamedIndividual
authenticates: User Account
definition: A credential is a physical/tangible object, a piece of knowledge, or a facet of a person's physical being that enables an individual access to a given physical facility or computer-based information system. Typically, credentials can be something a person knows (such as a number or PIN), something they have (such as an access badge), something they are (such as a biometric feature), something they do (measurable behavioral patterns) or some combination of these items. This is known as multi-factor authentication. The typical credential is an access card or key-fob, and newer software can also turn users' smartphones into access devices.

Credential Access Technique
type: Class
subclass of: ATTACK Enterprise Technique
subclass of: Offensive Technique
subclass of: Restriction
  on property: accesses
  some values from: Credential
subclass of: Restriction
  on property: enables
  some values from: Credential Access
subclass of: Restriction
  on property: may-access
  some values from: Password File
subclass of: Restriction
  on property: may-invoke
  some values from: Create Process
type: NamedIndividual
accesses: Credential
enables: Credential Access
may-access: Password File
may-invoke: Create Process

Credential Compromise Scope Analysis
type: Class
subclass of: User Behavior Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Credential
type: NamedIndividual
analyzes: Credential
kb-reference: Reference-AllLoginsSinceLastBoot MITRE
kb-reference: Reference-SystemsAndMethodsForDetectingCredentialTheft SymantecCorp
d3fend-id: D3-CCSA
definition: Determining which credentials may have been compromised by analyzing the user logon history of a particular system.
kb-article: ## How it works #### Memory Credentials may be stored in memory for a variety of reasons; on Windows, they may be stored in lsass.exe. Once a credential dumper like mimikatz runs and dumps the memory of lsass.exe, the credentials of every account logged on since boot are potentially compromised. When such an event occurs, this analytic will give the forensic context to identify compromised users. Those users could potentially be used in later events for additional logons. #### Hard disk Operating System may cache a certain number of credentials onto the hard disk to use as a source of truth if it cannot contact the credential server. In many versions of Microsoft Windows, the 10 most recent are cached by default; this setting can be changed in the Microsoft Management Console's Local Security Policy: ```Computer Configuration -> Windows Settings -> Local Policy -> Security Options -> Interactive Logon: Number of previous logons to cache -> 0``` Here we are not concerned with the alteration of the credentials but the fact that they might be read. If the attacker has physical access to the machine they are unlikely to be stopped from reading files on the filesystem. "In the event that the domain controller is unavailable Windows will check the last password hashes that has been cached in order to authenticate the user with the system. These password hashes are cached in the following registry setting: HKEY_LOCAL_MACHINE\SECURITY\Cache Mimikatz can retrieve these hashes if the following command is executed: lsadump::cache" [1] The Registry Hive, HKEY_LOCAL_MACHINE\SAM, which is stored in the supporting files %systemroot%\System32\Config\{Sam,sam.log,sam.sav}, contains the SAM file. DC: This is stored in %systemroot%\ntds\ntds.dit. (https://www.ultimatewindowssecurity.com/blog/default.aspx?d=10/2017) Sometimes memory, which contains credentials, could get on the hard disk. Like with hiberfil.sys in Windows. Equivalent on Linux In Linux, an attacker could read the /etc/s…

Credential Eviction
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Evict
type: NamedIndividual
enables: Evict
kb-reference: Reference-AccountMonitoring ForescoutTechnologies
d3fend-id: D3-CE
definition: Credential Eviction techniques disable or remove compromised credentials from a computer network.

Credential Hardening
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Harden
subclass of: Restriction
  on property: hardens
  some values from: Credential
type: NamedIndividual
enables: Harden
hardens: Credential
d3fend-id: D3-CH
definition: Credential Hardening techniques modify system or network properties in order to protect system or network/domain credentials.

Credential Management System
type: Class
subclass of: Service Application
type: NamedIndividual
definition: Credential Management, also referred to as a Credential Management System (CMS), is an established form of software that is used for issuing and managing credentials as part of public key infrastructure (PKI).

Credential Revocation
type: Class
subclass of: Credential Eviction
subclass of: Restriction
  on property: deletes
  some values from: Credential
type: NamedIndividual
deletes: Credential
kb-reference: Reference-RevokingaPreviouslyIssuedVerifiableCredential-Microsoft
d3fend-id: D3-CR
definition: Deleting a set of credentials permanently to prevent them from being used to authenticate.
kb-article: ## How it works Management servers with enterprise policies for account management provide the ability remove permissions, accounts, or credentials. Compromised credentials should be revoked to prevent further malicious activity.

Credential Rotation
type: Class
subclass of: Credential Hardening
subclass of: Restriction
  on property: regenerates
  some values from: Credential
type: NamedIndividual
kb-reference: Reference-PasswordandKeyRotation-SSH
regenerates: Credential
d3fend-id: D3-CRO
definition: Credential rotation is a security procedure in which authentication credentials, such as passwords, API keys, or certificates, are regularly changed or replaced to minimize the risk of unauthorized access.
kb-article: ## How it works Credentials can be systematically changed at predetermined intervals or based on specific events. Credentials such as user passwords may be rotated manually, but it is increasingly common to use an automated system to manage rotation of enterprise passwords, certificates and keys. ## Considerations - Rotation of credentials must be managed carefully to avoid inadvertent service interruption - Management servers with enterprise policies for account management provide the ability to change or reset passwords for accounts. Some organizations rotate credentials periodically to limit the risk of stolen credentials. - When responding to an incident, severity of compromise should be considered to determine what credentials to what accounts should be regenerated - If proactively rotating credentials periodically, several factors should be considered to determine the frequency. Also introduces some risk including promoting the creation of weak passwords and poor storage practices for employees and presents challenges in proper tracking.

Credential Scrubbing
type: Class
subclass of: Source Code Hardening
subclass of: Restriction
  on property: hardens
  some values from: Subroutine
type: NamedIndividual
hardens: Subroutine
kb-reference: Reference-SecretsManagementCheatSheet-OWASP
d3fend-id: D3-CS
definition: The systematic removal of hard-coded credentials from source code to prevent accidental exposure and unauthorized access.
kb-article: ## How it Works Credential Scrubbing involves identifying and eliminating hard-coded credentials such as usernames, passwords, API keys, and tokens from source code repositories. These credentials should be managed securely using environment variables, secret management tools, or secure vaults where they can be safely accessed when needed. ## Considerations * Developers should conduct regular audits of source code to ensure credentials are not hard-coded. * Exposed credentials found in version control history must be disabled and replaced promptly. * Adopt role-based access controls and credential rotation policies to minimize security risks.

Credential Transmission Scoping
type: Class
subclass of: Access Mediation
subclass of: Restriction
  on property: isolates
  some values from: Credential
type: NamedIndividual
isolates: Credential
d3fend-id: D3-CTS
definition: Limiting the transmission of a credential to a scoped set of relying parties.
synonym: Phishing Resistant Authentication

Cryptographic Key
type: Class
subclass of: Digital Information
type: NamedIndividual
definition: In cryptography, a key is a piece of information (a parameter) that determines the functional output of a cryptographic algorithm. For encryption algorithms, a key specifies the transformation of plaintext into ciphertext, and vice versa for decryption algorithms. Keys also specify transformations in other cryptographic algorithms, such as digital signature schemes and message authentication codes.

Custom Archive File
type: Class
subclass of: Archive File
type: NamedIndividual
definition: A custom archive file is an archive file conforming to a custom format; that is, an archive file that does not conform to a common standard.

Cyber Action
type: Class
subclass of: Action

Cyber Sensor
type: Class
subclass of: Sensor

Cyber Technique
type: Class
subclass of: Technique
subclass of: Restriction
  on property: implemented-by
  some values from: Procedure

CycleGAN
type: Class
subclass of: Image-to-Image Translation GAN
type: NamedIndividual
d3fend-id: D3A-CYC
definition: The Cycle Generative Adversarial Network (CycleGAN) is an approach to training a deep convolutional neural network for image-to-image translation tasks by mapping between input and output images using unpaired dataset.
kb-article: ## References Esri. (n.d.). How CycleGAN Works. [Link](https://developers.arcgis.com/python/guide/how-cyclegan-works/)

D3FEND Core
type: Class
type: NamedIndividual

D3FEND KB Thing
type: Class

DBSCAN
type: Class
subclass of: Density-based Clustering
type: NamedIndividual
d3fend-id: D3A-DBS
definition: A density-based clustering algorithm that works on the assumption that clusters are dense regions in space separated by regions of lower density.
kb-article: ## References Analytics Vidhya. (2020, September 15). How DBSCAN Clustering Works: A Comprehensive Guide with Implementations in Python. [Link](https://www.analyticsvidhya.com/blog/2020/09/how-dbscan-clustering-works/#:~:text=DBSCAN%20is%20a%20density%2Dbased,points%20into%20a%20single%20cluster.)

DHCP Ack Event
type: Class
subclass of: DHCP Event
definition: An event where a DHCP server sends an ACK message to acknowledge a client's REQUEST, confirming the allocation of an IP address and associated network settings.
alternative label: DHCPACK

DHCP Discover Event
type: Class
subclass of: DHCP Event
definition: An event where a DHCP client broadcasts a DISCOVER message to identify available DHCP servers capable of providing IP configuration.
alternative label: DHCPDISCOVER

DHCP Event
type: Class
subclass of: Application Layer Event
subclass of: UDP Event
subclass of: Restriction
  on property: has-participant
  some values from: DHCP Network Traffic
definition: An event involving the Dynamic Host Configuration Protocol (DHCP), a UDP-based protocol used to dynamically assign IP addresses and configure network parameters, enabling devices to communicate efficiently on a network.

DHCP Inform Event
type: Class
subclass of: DHCP Event
definition: An event where a DHCP client sends an INFORM message to request configuration parameters, such as DNS or gateway information, without requiring IP address assignment.
alternative label: DHCPINFORM

DHCP Lease Expire Event
type: Class
subclass of: DHCP Event
definition: An event indicating that a DHCP lease has expired, rendering the previously assigned IP address available for reassignment to other devices.
alternative label: DHCPLEASEEXPIRE

DHCP Nak Event
type: Class
subclass of: DHCP Event
definition: An event where a DHCP server sends a NAK message to reject a client's REQUEST, indicating that the requested configuration cannot be granted.
alternative label: DHCPNAK

DHCP Network Traffic
type: Class
subclass of: Network Traffic
type: NamedIndividual
definition: DHCP Network Traffic is network traffic related to the DHCP protocol, used by network nodes to negotiate and configure either IPv4 or IPv6 addresses.

DHCP Offer Event
type: Class
subclass of: DHCP Event
definition: An event where a DHCP server sends an OFFER message to a client in response to a DISCOVER request, proposing an IP address and associated configuration parameters.
alternative label: DHCPOFFER

DHCP Release Event
type: Class
subclass of: DHCP Event
definition: An event where a DHCP client sends a RELEASE message to relinquish its assigned IP address and cancel any remaining lease duration.
alternative label: DHCPRELEASE

DHCP Request Event
type: Class
subclass of: DHCP Event
definition: An event where a DHCP client sends a REQUEST message to confirm or renew its desired IP configuration with a specific DHCP server.
alternative label: DHCPREQUEST

DHCP Server
type: Class
subclass of: Server
definition: A Dynamic Host Configuration Protocol (DHCP) server is a type of server that assigns IP addresses to computers. DHCP servers are used to assign IP addresses to computers and other devices automatically. The DHCP server is responsible for assigning the unique IP address to each device.

DNN-based Clustering
type: Class
subclass of: ANN-based Clustering
type: NamedIndividual
d3fend-id: D3A-DBC
definition: DNNs serve for clustering as mappings to better representations. The features of these representations can be drawn from different layers of the network or even from several layers.
kb-article: ## References OpenReview. (n.d.). Unsupervised Clustering using Pseudo Ensemble Models. [Link](https://openreview.net/pdf?id=B1eT9VMgOX)

DNS Allowlisting
type: Class
subclass of: Network Isolation
subclass of: Restriction
  on property: blocks
  some values from: Outbound Internet DNS Lookup Traffic
type: NamedIndividual
blocks: Outbound Internet DNS Lookup Traffic
kb-reference: Reference-DNSWhitelist-DNSWL-EmailAuthenticationMethodExtension
d3fend-id: D3-DNSAL
definition: Permitting only approved domains and their subdomains to be resolved.
synonym: DNS Whitelisting

DNS Cache Eviction
type: Class
subclass of: Object Eviction
subclass of: Restriction
  on property: deletes
  some values from: DNS Record
type: NamedIndividual
deletes: DNS Record
d3fend-id: D3-DNSCE
definition: Flushing DNS to clear any IP addresses or other DNS records from the cache.
kb-article: # How it works Flushing the DNS Cache will clear the IP addresses of websites you have visited recently. This can help remediate DNS Cache Poisoning attacks, which is a type of cyber attack where corrupted DNS data is inserted into the cache, causing redirects to malicious websites. On windows, the DNS cache can be wiped by issuing the command `ipconfig /flushdns`.
synonym: Flush DNS Cache

DNS Denylisting
type: Class
subclass of: Network Isolation
subclass of: Restriction
  on property: blocks
  some values from: DNS Network Traffic
type: NamedIndividual
blocks: DNS Network Traffic
kb-reference: Reference-UseDNSPolicyForApplyingFiltersOnDNSQueries
d3fend-id: D3-DNSDL
definition: Blocking DNS Network Traffic based on criteria such as IP address, domain name, or DNS query type.
kb-article: ## How it works Rules are implemented that filter DNS queries using criteria such as: - Client subnet - Type of network protocol used in query - Fully qualified domain name (FQDN) of record in the query - DNS Server IP address that received the DNS request - Type of DNS record being queried - Time of day the query is received - Size of the response For example, a DNS policy can be created for blocking DNS queries for FQDNs that have been identified as unauthorized. ## Considerations - Implementation considerations for DNS filtering policies to avoid over-blocking or under-blocking domains. - Continuous maintenance of unauthorized domain lists is needed to keep up to date with possible site content changes. - File sharing or content delivery networks may require other filtering techniques that are more fine-grained (URL blocking). - Access to malicious websites or other network resources directly by IP instead of by DNS record, or after alteration of local DNS hosts file, may not result in DNS network traffic.
synonym: DNS Blacklisting

DNS Event
type: Class
subclass of: Application Layer Event
subclass of: Class
  union of: TCP Event
  union of: UDP Event
subclass of: Restriction
  on property: has-participant
  some values from: DNS Network Traffic
definition: An event involving the Domain Name System (DNS), which translates domain names to IP addresses and operates over UDP and TCP.

DNS Lookup
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: A Domain Name System (DNS) lookup is a record returned from a DNS resolver after querying a DNS name server. Typically considered an A or AAAA record, where a domain name is resolved to an IPv4 or IPv6 address, respectively.

DNS Network Traffic
type: Class
subclass of: Network Traffic
type: NamedIndividual
definition: DNS network traffic is network traffic related to queries and responses involving the Domain Name System. DNS traffic can involve clients, servers such as relays or resolvers. This includes only network traffic conforming to standard DNS protocol; not custom protocols.

DNS Query Event
type: Class
subclass of: DNS Event
definition: An event where a DNS query is made to resolve a domain name.

DNS Record
type: Class
subclass of: Record
type: NamedIndividual
definition: A Domain Name System (DNS) record is a record of information returned to clients seeking to find computers, services, and other resources connected to the Internet or a private network. Record information is stored on a domain name server so it can respond to DNS queries from clients.There are a variety of record types, depending on the client's information needs. Common types include Start of Authority, IP addresses, SMTP mail exchangers, name servers, reverse DNS lookup pointers, etc.

DNS Response Event
type: Class
subclass of: DNS Event
definition: An event where a DNS server responds to a query with resolution data.

DNS Server
type: Class
subclass of: Server
definition: A Domain Name System (DNS) name server is a kind of name server. Domain names are one of the two principal namespaces of the Internet. The most important function of DNS servers is the translation (resolution) of human-memorable domain names and hostnames into the corresponding numeric Internet Protocol (IP) addresses, the second principal name space of the Internet which is used to identify and locate computer systems and resources on the Internet. (en). More generally, a name server is a computer application that implements a network service for providing responses to queries against a directory service. It translates an often humanly meaningful, text-based identifier to a system-internal, often numeric identification or addressing component. This service is performed by the server in response to a service protocol request.

DNS Traffic Analysis
type: Class
subclass of: Network Traffic Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Outbound Internet DNS Lookup Traffic
subclass of: Restriction
  on property: may-contain
  some values from: DNS Lookup
type: NamedIndividual
analyzes: Outbound Internet DNS Lookup Traffic
kb-reference: Reference-HeuristicBotnetDetection PaloAltoNetworksInc
kb-reference: Reference-MethodAndSystemForDetectingAlgorithm-generatedDomains VECTRANETWORKSInc
kb-reference: Reference-PredictingDomainGenerationAlgorithmsWithLongShort-TermMemoryNetworks
kb-reference: Reference-SinkholingBadNetworkDomainsByRegisteringTheBadNetworkDomainsOnTheInternet PaloAltoNetworksInc
may-contain: DNS Lookup
d3fend-id: D3-DNSTA
definition: Analysis of domain name metadata, including name and DNS records, to determine whether the domain is likely to resolve to an undesirable host.
kb-article: ## How it works This technique can be accomplished in a number of ways. * One example analytic determines whether or not a domain name was generated with an algorithm. Domain generation algorithms (DGAs) are sometimes used to create a domain name automatically that will resolve to C2 infrastructure, without directly coding the domains in question into the malicious code. * Another method analyzes information about domains that have been visited, including whether a domain name is longer than a common length, if a dynamic DNS domain was visited, if a fast-flux domain was visited, and if a recently created domain was visited. These factors are used to develop a score and if that score is over a certain threshold, an alert is generated. * Collected malware samples can be executed in a virtual environment to identify network domains that are connected to during execution. The network domains are then generated into signatures to identity bad domains for other hosts. This technique does not check for content hosted at the domain. ## Considerations * DNS produces a large amount of traffic which can be resource-intensive to analyze in real time. * If a server is compromised, for example, as part of a watering hole attack, but the DNS information pointing to that server is not altered, this technique would not catch such an incident.
synonym: Domain Name Analysis

Data Artifact Server
type: Class
subclass of: Artifact Server
definition: A data artifact server provides access services to content in a content repository. The content repository or content store is a database of digital content with an associated set of data management, search and access methods allowing application-independent access to the content, rather like a digital library, but with the ability to store and modify content in addition to searching and retrieving. The content repository acts as the storage engine for a larger application such as a content management system or a document management system, which adds a user interface on top of the repository's application programming interface.

Data Dependency
type: Class
subclass of: Dependency
type: NamedIndividual
synonym: Transactional Dependency

Data Exchange Mapping
type: Class
subclass of: System Mapping
subclass of: Restriction
  on property: maps
  some values from: Data Dependency
type: NamedIndividual
kb-reference: Reference-CatiaUAFPlugin
kb-reference: Reference-UnifiedArchitectureFrameworkUAF
maps: Data Dependency
d3fend-id: D3-DEM
definition: Data exchange mapping identifies and models the organization's intended design for the flows of the data types, formats, and volumes between systems at the application layer.
synonym: Data Flow Mapping
synonym: Information Exchange Mapping

Data Inventory
type: Class
subclass of: Asset Inventory
subclass of: Restriction
  on property: inventories
  some values from: Database
subclass of: Restriction
  on property: inventories
  some values from: Document File
type: NamedIndividual
inventories: Database
inventories: Document File
kb-reference: Reference-DataProcessingAndScanningSystemsForGeneratingAndPopulatingADataInventory
d3fend-id: D3-DI
definition: Data inventorying identifies and records the schemas, formats, volumes, and locations of data stored and used on the organization's architecture.
synonym: Data Discovery
synonym: Data Inventorying

Data Link Link
type: Class
subclass of: Logical Link
definition: A communication link between two network devices connected directly at the physical layer and on the same network segment; i.e., an OSI Layer 2 link.
synonym: Data Link Layer Link
synonym: Layer-2 Link
synonym: Link Layer Link

Database
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: A database is an organized collection of data, generally stored and accessed electronically from a computer system. Where databases are more complex they are often developed using formal design and modeling techniques.

Database File
type: Class
subclass of: File
type: NamedIndividual

Database Query
type: Class
subclass of: Command
type: NamedIndividual
definition: A specific query expressed in SQL, SPARQL, or similar language against a database.

Database Query String Analysis
type: Class
subclass of: Process Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Database Query
type: NamedIndividual
analyzes: Database Query
kb-reference: Reference-SystemAndMethodForInternetSecurity CylanceInc
d3fend-id: D3-DQSA
definition: Analyzing database queries to detect [SQL Injection](https://capec.mitre.org/data/definitions/66.html).
kb-article: ## How it works Some implementations use software hooks to intercept function calls related to database query operations. Other implementations might intercept or collect network traffic. The database query string is then extracted and analyzed with various methods, for example: * Detecting specific administrative SQL commands * Anomalous sequences of commands when compared to a statistical baseline. * Anomalous commands for a given user role. ## Considerations Some capabilities sanitize queries before permitting them to be transmitted to the database. This incurs risks such altering data in an undesired way or breaking application functionality.

Database Server
type: Class
subclass of: Server
subclass of: Restriction
  on property: contains
  some values from: Database
type: NamedIndividual
contains: Database
definition: A database server is a server which uses a database application that provides database services to other computer programs or to computers, as defined by the client-server model. Database management systems (DBMSs) frequently provide database-server functionality, and some database management systems (such as MySQL) rely exclusively on the client-server model for database access (while others e.g. SQLite are meant for using as an embedded database). For clarification, a database server is simply a server that maintains services related to clients via database applications.
alternative label: Network Database Resource

Datalog
type: Class
subclass of: Logic Programming
type: NamedIndividual
d3fend-id: D3A-DAT
definition: Datalog is a declarative logic programming language that is a syntactically a subset of Prolog.
kb-article: ## How it works Datalog generally uses a bottom-up rather than top-down evaluation model. This difference yields significantly different behavior and properties from Prolog. It is often used as a query language for deductive databases. Datalog has been applied to problems in data integration, networking, program analysis, and more. ## References 1. Datalog. (2023, April 20). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Datalog)

Dead Code Elimination
type: Class
subclass of: Application Hardening
type: NamedIndividual
kb-reference: Reference-DeadCodeElimination
d3fend-id: D3-DCE
definition: Removing unreachable or "dead code" from compiled source code.
kb-article: ## How it works Dead code is code that is considered unreachable by normal program execution. Dead code can be created by adding code under a condition that never evaluates to true. Dead code should be removed since this type of code can produce unexpected results, if accidentally or maliciously forced to execute. Dead code identification is typically performed by algorithms that implement program flows analysis looking for unreachable code. The dead code is eliminated by instructing compilers to remove the code through compiler flags, i.e., '-fdce' is used for Dead Code Elimination. ## Considerations Code can also be deemed unreachable for certain run-time conditions. Different deployed systems and environments may contain some code that is unreachable for the given environment. This technique does not consider run-time conditions for unreachable code.

Deceive
type: Class
subclass of: Defensive Tactic
type: NamedIndividual
type: Defensive Tactic
definition: The deceive tactic is used to advertise, entice, and allow potential attackers access to an observed or controlled environment.
display-order: 3
display-priority: 0

Decision Tree
type: Class
subclass of: Classification
type: NamedIndividual
d3fend-id: D3A-DT
definition: Decision tree learning is a supervised learning approach used in statistics, data mining, and machine learning. In this formalism, a classification or regression decision tree is used as a predictive model to draw conclusions about a set of observations.
kb-article: ## How it works A decision tree starts with a root node, which does not have any incoming branches. The outgoing branches from the root node then feed into the internal nodes, also known as decision nodes. Based on the available features, both node types conduct evaluations to form homogenous subsets, which are denoted by leaf nodes, or terminal nodes. The leaf nodes represent all the possible outcomes within the dataset. ## Considerations While the basic underlying model is that of a decision tree, the decision tree node criteria, and the method for identifying splits varies significantly depending on the learning algorithm selected (e.g., CART, ID3, C4.5, C5.0, CHAID, MARS.) Extensions like linear and logistic trees can add additional expressiveness as well. ## Key Test Considerations - **Machine Learning**: - **Verify the dataset quality**: Check the data to make sure it is free of errors. Quantify the degree of missing values, outliers, and noise in the data collection. If the data quality is low, it may be difficult or impossible to create models and systems with the desired performance. - **Verify development datasets are representative**: of expected operational environment and data collection means. Compare distributions of dataset features and labels with exploratory data analysis and assess the difference in tests on training data and tests on evaluation data (where the evaluation data must be drawn from a representative dataset.) - **Use a variety of data sets**: where available and applicable, to reflect different operating and environment conditions that are likley to be be encountered. - **Use software libraries**: and tools built for ML where possible, so that the underlying code is verified by prior use.** - **Diagnose model errors with domain SMEs**: Have problem domain SMEs investigate model errors for conditions for which the model may underperform and suggest refinements. - **Classification**: - **Use Standard Classification Performance Measures*…

Decision Tree Regression
type: Class
subclass of: Regression Analysis Learning
type: NamedIndividual
d3fend-id: D3A-DTR
definition: Decision Trees Regression is asupervised learning method with the goal to create a model that predicts the value of a target variable by learning simple decision rules inferred from the data features
kb-article: ## References scikit-learn. (n.d.). Decision Trees. [Link](https://scikit-learn.org/stable/modules/tree.html#tree)

Decoy Artifact
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: may-contain
  some values from: Digital Artifact
type: NamedIndividual
may-contain: Digital Artifact
definition: A decoy is an imitation digital artifact in any sense of a digital artifact, object, or phenomenon that is intended to deceive a cyber attacker's surveillance devices or mislead their evaluation. Examples include fake files, accounts, hosts (honeypots), and network segments (honeynets).
alternative label: Decoy
alternative label: Decoy Object
alternative label: Lure
alternative label: Trap

Decoy Environment
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Deceive
subclass of: Restriction
  on property: manages
  some values from: Decoy Artifact
type: NamedIndividual
enables: Deceive
manages: Decoy Artifact
d3fend-id: D3-DE
definition: A Decoy Environment comprises hosts and networks for the purposes of deceiving an attacker.
kb-article: ## Technique Overview Systems in a decoy environment are typically configured so that some detectable means of communication does not have any legitimate business purpose. Any communication via these means should be logged and analyzed to find potential indicators of compromise for a possible past or future attack against other systems.
synonym: Honeypot

Decoy File
type: Class
subclass of: Decoy Object
subclass of: Restriction
  on property: spoofs
  some values from: File
type: NamedIndividual
kb-reference: Reference-OpenSourceIntelligenceDeceptions IllusiveNetworksLtd
kb-reference: Reference-SystemAndAMethodForIdentifyingThePresenceOfMalwareAndRansomwareUsingMini-trapsSetAtNetworkEndpoints FidelisCybersecuritySolutionsInc
kb-reference: Reference-SystemAndMethodsThereofForPreventingRansomwareFromEncryptingDataElementsStoredInAMemoryOfAComputer-basedSystem PaloAltoNetworksInc
kb-reference: Reference-SupplyChainCyber-deception Cymmetria,Inc.
spoofs: File
d3fend-id: D3-DF
definition: A file created for the purposes of deceiving an adversary.
kb-article: ## How it works The decoy file is made available as a local or network resource. Accesses to the file may be monitored. The files may be configurations, documents, executables, or other file types. ## Considerations Properties of the file such as cryptographic checksums, file creation date, file modified date, file size, file owner etc may be modified to improve the credibility of the file. ## Example * A CSV file with decoy user credentials is placed on a system. The system or network is then monitored to detect any accesses to the decoy files.

Decoy Network Resource
type: Class
subclass of: Decoy Object
subclass of: Restriction
  on property: spoofs
  some values from: Network Resource
type: NamedIndividual
kb-reference: Reference-AutomaticallyGeneratingNetworkResourceGroupsAndAssigningCustomizedDecoyPoliciesThereto IllusiveNetworksLtd
kb-reference: Reference-Deception-BasedResponsesToSecurityAttacks CrowdstrikeInc
kb-reference: Reference-DynamicSelectionAndGenerationOfAVirtualCloneForDetonationOfSuspiciousContentWithinAHoneyNetwork PaloAltoNetworksInc
kb-reference: Reference-SystemAndMethodForIdentifyingThePresenceOfMalwareUsingMini-trapsSetAtNetworkEndpoints FidelisCybersecuritySolutionsInc
spoofs: Network Resource
d3fend-id: D3-DNR
definition: Deploying a network resource for the purposes of deceiving an adversary.
kb-article: ## How it works Decoy network resources are deployed to web application servers, network file shares, or other network based sharing services. A "honeypot" may serve a variety of decoy network resources. ## Considerations * Developing a deployment and placement strategy for the decoy network resource. * Personnel responsible for creation of decoy networks should consider the potential for resource exhaustion through denial of service attacks. ## Examples * Honeypots are typically used to mimic a known system with fake vulnerabilities. This may attract attackers to the honeypot. * Decoy accounts are also used to scan for attempted logins. The decoy accounts can provide security analysts with the attacker's potential intents and strategies. * Tarpits are used to monitor unallocated IP space for unauthorized network activity.

Decoy Object
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Deceive
type: NamedIndividual
enables: Deceive
d3fend-id: D3-DO
definition: A Decoy Object is created and deployed for the purposes of deceiving attackers.
kb-article: ## Technique Overview Decoy objects are typically configured with detectable means of communication but do not have any legitimate business purpose. Any communication via or to these objects should be logged and analyzed to find potential indicators of compromise for a possible past or future attack against other systems.
synonym: Lure

Decoy Persona
type: Class
subclass of: Decoy Object
subclass of: Restriction
  on property: spoofs
  some values from: User
type: NamedIndividual
kb-reference: Reference-DecoyPersonasForSafeguardingOnlineIdentityUsingDeception
kb-reference: Reference-DecoyAndDeceptiveDataObjectTechnology Cymmetria,Inc.
spoofs: User
d3fend-id: D3-DP
definition: Establishing a fake online identity to misdirect, deceive, and or interact with adversaries.
kb-article: ## How it works A false online identity is created for the purposes of interacting with adversaries in a direct or indirect manner. This includes the associated email addresses, social media accounts, and other online communication profiles. ## Considerations * Include phone numbers and online social profiles as well as automatically or manually responding to contact made to the persona to improve realism. * Continuous updating and managing the decoy personas and online activity streams to ensure personas do not become stale and outdated.

Decoy Public Release
type: Class
subclass of: Decoy Object
type: NamedIndividual
kb-reference: Reference-MockAttackCybersecurityTrainingSystemAndMethods WOMBATSECURITYTECHNOLOGIESInc
d3fend-id: D3-DPR
definition: Issuing publicly released media to deceive adversaries.
kb-article: ## How it works Publicly released media includes press release, videos, or other marketing collateral. The media may include URLs, points of contact, or other identifiers to entice interaction from adversaries. ## Considerations * Information used in decoy public released media must contain enough realism to deceive and provide interaction from adversaries. * Continuous development, creation, and distribution of media and identifiers are needed to ensure adversary interaction continues over time. * Decoy public releases could be placed on platforms with different degrees of ownership, including entirely enterprise-owned infrastructure, IaaS, and SaaS (including social applications). Platforms that are not entirely enterprise-owned may be more likely to gather information

Decoy Session Token
type: Class
subclass of: Decoy Object
subclass of: Restriction
  on property: spoofs
  some values from: Session Token
type: NamedIndividual
kb-reference: Reference-DecoyAndDeceptiveDataObjectTechnology CymmetriaInc
spoofs: Session Token
d3fend-id: D3-DST
definition: An authentication token created for the purposes of deceiving an adversary.
kb-article: ## How it works Usage of decoy session tokens may be monitored to track attacker behavior or otherwise control the beliefs of the attacker. ## Considerations * Interaction and activity with the decoy session token must be constantly monitored and analyzed to detect unauthorized activity. * Session tokens are typically short-lived and therefore the decoy must be continuously updated to provide the appearance of it being used in the production environment. * Automated tools can assist with maintenance and updates by automatically adjusting the decoy session token and environment to mimic the production environment.

Decoy User Credential
type: Class
subclass of: Decoy Object
subclass of: Restriction
  on property: spoofs
  some values from: Credential
type: NamedIndividual
kb-reference: Reference-DecoyAndDeceptiveDataObjectTechnology CymmetriaInc
kb-reference: Reference-DecoyNetwork-BasedServiceForDeceivingAttackers-AmazonTechnologies
kb-reference: Reference-SystemAndMethodForIdentifyingThePresenceOfMalwareUsingMini-trapsSetAtNetworkEndpoints FidelisCybersecuritySolutionsInc
spoofs: Credential
d3fend-id: D3-DUC
definition: A Credential created for the purpose of deceiving an adversary.
kb-article: ## How it works A detection analytic is developed to determine when a user uses decoy credentials. Subsequent actions by that user may be monitored or controlled by the defender. A credential may be: * Domain username and password * Local system username and password ## Considerations * Decoy credentials should be integrated with a larger decoy environment to ensure that when decoy credentials are compromised, the credentials are used to interact with a decoy asset that is being monitored. * Continuous maintenance and updates are needed to ensure the legitimacy of the larger decoy environment and specifically the assets that utilize the decoy credentials.

Deep Convolutional GAN
type: Class
subclass of: Image Synthesis GAN
type: NamedIndividual
d3fend-id: D3A-DCG
definition: Deep Convolutional GAN (DCGAN) uses convolutional and convolutional-transpose layers in the generator and discriminator, respectively.
kb-article: ## References Analytics Vidhya. (2021). Deep Convolutional Generative Adversarial Network (DCGAN) for Beginners. [Link](https://www.analyticsvidhya.com/blog/2021/07/deep-convolutional-generative-adversarial-network-dcgan-for-beginners/)
synonym: DCGAN

Deep Neural Network Classification
type: Class
subclass of: Artificial Neural Network Classification
type: NamedIndividual
d3fend-id: D3A-DNNC
definition: A deep neural network (DNN) is an artificial neural network (ANN) with multiple layers between the input and output layers. There are different types of neural networks but they always consist of the same components: neurons, synapses, weights, biases, and functions. These components as a whole function similarly to a human brain, and can be trained like any other ML algorithm
kb-article: ## References Deep learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Deep_learning).

Deep Q-learning
type: Class
subclass of: Q-Learning
type: NamedIndividual
d3fend-id: D3A-DQL
definition: Uses a deep convolutional neural network, with layers of tiled convolutional filters to mimic the effects of receptive fields.
kb-article: ## References Q-learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Q-learning#Deep_Q-learning).

Default User Account
type: Class
subclass of: User Account
type: NamedIndividual
definition: Default accounts are those that are built-into an OS, such as the Guest or Administrator accounts on Windows systems or default factory/provider set accounts on other types of systems, software, or devices.

Defense Evasion Technique
type: Class
subclass of: ATTACK Enterprise Technique
subclass of: Offensive Technique
subclass of: Restriction
  on property: enables
  some values from: Defense Evasion
type: NamedIndividual
enables: Defense Evasion

Defensive Action
type: Class
subclass of: Cyber Action

Defensive Tactic
type: Class
subclass of: Goal
subclass of: Restriction
  on property: enabled-by
  some values from: Defensive Technique
definition: a plan for attaining a particular goal

Defensive Technique
type: Class
subclass of: Cyber Technique
subclass of: Restriction
  on property: enables
  some values from: Defensive Tactic
subclass of: Restriction
  on property: kb-reference
  some values from: Technique Reference
subclass of: Restriction
  on property: d3fend-id
  some values from: string
subclass of: Restriction
  on property: date
  some values from: dateTime
type: NamedIndividual
definition: A method which makes a computer system more difficult to attack.
display-baseurl: /technique/
synonym: Countermeasure Technique
synonym: Defensive Capability Feature
synonym: Technical Security Control

Delete File
type: Class
subclass of: System Call
subclass of: Restriction
  on property: deletes
  some values from: File
type: NamedIndividual
deletes: File
definition: Remove a file from a machine.

Density-based Clustering
type: Class
subclass of: Cluster Analysis
type: NamedIndividual
d3fend-id: D3A-DBC
definition: Density-based clustering connects areas of high example density into clusters. This allows for arbitrary-shaped distributions as long as dense areas can be connected.
kb-article: ## References Google Developers. (n.d.). Clustering algorithms. [Link](https://developers.google.com/machine-learning/clustering/clustering-algorithms)

Density-weighted Method
type: Class
subclass of: Active Learning
type: NamedIndividual
d3fend-id: D3A-DWM
definition: An Actvie Learning technique that uses a density estimate meta-parameter to avoid sampling sparsely populated regions of the feature space and can be based parametrically or from a parameter free model.
kb-article: ## References Intro to Active Learning. inovex Blog. [Link](https://www.inovex.de/de/blog/intro-to-active-learning/).

Deontic Logic
type: Class
subclass of: Modal Logic
type: NamedIndividual
d3fend-id: D3A-DL
definition: Deontic logic addresses the modality of obligations and norms; i.e., the modality of morality.
kb-article: ## References 1. Deontic logic. (2023, June 4). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Modal_logic#Deontic_logic)

Dependency
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: dependent
  some values from: D3FEND Core
subclass of: Restriction
  on property: provider
  some values from: D3FEND Core
type: NamedIndividual
dependent: D3FEND Core
provider: D3FEND Core
definition: A dependency is the relationship of relying on or being controlled by someone or something else. This class reifies dependencies that correspond to the object property depends-on.

Description Logic
type: Class
subclass of: Symbolic AI
type: NamedIndividual
d3fend-id: D3A-DL
definition: A description logic (DL) is a form of logic usually more expressive than propositional logic but less expressive than first-order logic.
kb-article: ## How it works The core reasoning problems for description logics (DLs) are (usually) decidable, and efficient decision procedures have been designed and implemented for these problems. There are general, spatial, temporal, spatiotemporal, and fuzzy description logics, and each description logic features a different balance between expressive power and reasoning complexity by supporting different sets of mathematical constructors. DLs are used in artificial intelligence to describe and reason about the relevant concepts of an application domain (known as terminological knowledge). It is of particular importance in providing a logical formalism for ontologies and the Semantic Web: the Web Ontology Language (OWL) and its profiles are based on DLs. ## References 1. Description logic. (2023, April 16). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Description_logic)

Descriptive Statistics
type: Class
subclass of: Statistical Method
type: NamedIndividual
d3fend-id: D3A-DS
definition: Descriptive statistics provide simple summaries about the sample and about the observations that have been made.
kb-article: ## References Wikipedia. (n.d.). Descriptive statistics. [Link](https://en.wikipedia.org/wiki/Descriptive_statistics)

Deserialization Function
type: Class
subclass of: Subroutine
type: NamedIndividual
definition: Function with an input of serialized data which deserializes that data, usually with data parsing methods.

Desktop Computer
type: Class
subclass of: Personal Computer
definition: A desktop computer is a personal computer designed for regular use at a single location on or near a desk or table due to its size and power requirements. The most common configuration has a case that houses the power supply, motherboard (a printed circuit board with a microprocessor as the central processing unit (CPU), memory, bus, and other electronic components, disk storage (usually one or more hard disk drives, solid state drives, optical disc drives, and in early models a floppy disk drive); a keyboard and mouse for input; and a computer monitor, speakers, and, often, a printer for output. The case may be oriented horizontally or vertically and placed either underneath, beside, or on top of a desk.

Detect
type: Class
subclass of: Defensive Tactic
type: NamedIndividual
type: Defensive Tactic
definition: The detect tactic is used to identify adversary access to or unauthorized activity on computer networks.
display-order: 1
display-priority: 0

Detection Event
type: Class
subclass of: Security Event
type: NamedIndividual
related: Detect
definition: An event capturing the identification of a potential security issue, such as unauthorized access attempts, policy violations, or anomalous activities. Detection events form the foundation of cybersecurity monitoring and response.

Developer Application
type: Class
subclass of: User Application
definition: An application used to develop computer software including applications used for software construction, analysis, testing, packaging, or management.

Dial Up Modem
type: Class
subclass of: Modem
definition: A dial-up modem transmits computer data over an ordinary switched telephone line that has not been designed for data use. This contrasts with leased line modems, which also operate over lines provided by a telephone company, but ones which are intended for data use and do not impose the same signaling constraints. The modulated data must fit the frequency constraints of a normal voice audio signal, and the modem must be able to perform the actions needed to connect a call through a telephone exchange, namely: picking up the line, dialing, understanding signals sent back by phone company equipment (dial tone, ringing, busy signal,) and on the far end of the call, the second modem in the connection must be able to recognize the incoming ring signal and answer the line.

Differential Volume Snapshot
type: Class
subclass of: Volume Snapshot
definition: A differential volume snapshot is a point-in-time capture of the files and directories that were changed since the last full snapshot.

Digital Artifact
type: Class
subclass of: Artifact
type: NamedIndividual
definition: An information-bearing artifact (object) that is, or is encoded to be used with, a digital computer system. This concept is broad to include the literal instances of an artifact, or an implicit summarization of changes to or properties of other artifacts.
display-baseurl: /dao/artifact/
synonym: Digital Asset

Digital Event
type: Class
subclass of: Event
type: NamedIndividual
definition: A digital event represents an observable occurrence, action, or state change within digital systems, networks, or their interactions. These events are characterized by their impact on the confidentiality, integrity, availability, or functionality of digital resources, processes, identities, or communications. Digital events are essential units of information in cybersecurity, serving as the basis for detecting threats, analyzing anomalies, and orchestrating responses in complex, interconnected environments.

Digital Event Record
type: Class
subclass of: Record
subclass of: Restriction
  on property: records
  some values from: Digital Event
type: NamedIndividual
records: Digital Event
definition: A digital event record is a structured representation of a digital event, encapsulating all relevant details about the occurrence for storage, analysis, and response. These records serve as the primary artifacts for cybersecurity operations, enabling threat detection, forensic investigations, and compliance reporting. Digital event records include metadata such as timestamps, origin, context, and associated resources, ensuring traceability and actionable intelligence in digital ecosystems.

Digital Fingerprint
type: Class
subclass of: Identifier
definition: A digital signature uniquely identifies data and has the property that changing a single bit in the data will cause a completely different message digest to be generated.

Digital Identity
type: Class
subclass of: Digital Information
subclass of: Restriction
  on property: identified-by
  some values from: Identifier
type: NamedIndividual
identified-by: Identifier
kb-reference: Reference-CNNSI-4009
definition: The unique representation of a subject engaged in an online transaction. A digital identity is always unique in the context of a digital service, but does not necessarily need to uniquely identify the subject in all contexts. In other words, accessing a digital service may not mean that the subject's real-life identity is known. Note: There is no single, widely accepted definition for this term and context is important. This definition is specific to online transactions.
comment: Variously describes or designates. Designation is not compete or definite without context. The representation generally can be identified by a unique identifier, though this may be private information.

Digital Information
type: Class
subclass of: Digital Artifact

Digital Information Bearer
type: Class
subclass of: Digital Artifact

Digital System
type: Class
subclass of: Digital Information Bearer
subclass of: System
type: NamedIndividual
definition: A digital system is a group of interacting or interrelated digital artifacts that act according to a set of rules to form a unified whole. A digital system, surrounded and influenced by its environment, is described by its boundaries, structure and purpose and expressed in its functioning. Systems are the subjects of study of systems theory.

Dimension Reduction
type: Class
subclass of: Unsupervised Learning
type: NamedIndividual
d3fend-id: D3A-DR
definition: Dimensionality reduction is a key technique within unsupervised learning. It compresses the data by finding a smaller, different set of variables that capture what matters most in the original features, while minimizing the loss of information.
kb-article: ## References O'Reilly Media. (n.d.). Chapter 7. Machine Learning and Security: Protecting Systems with Data and Algorithms. [Link](https://www.oreilly.com/library/view/machine-learning-and/9781492073048/ch07.html)

Direct Physical Link Mapping
type: Class
subclass of: Physical Link Mapping
type: NamedIndividual
kb-reference: Reference-NetworkMapping
d3fend-id: D3-DPLM
definition: Direct physical link mapping creates a physical link map by direct observation and recording of the physical network links.
kb-article: ## How it works Direct Physical Link Mapping involves a manual process where a network engineer or administrator physically observes and documents the physical connections within the network infrastructure. ## Considerations * Constructing and maintaining physical topologies for extensive networks can be challenging and time-consuming using manual methods. Therefore, where feasible, automated methods like active physical link mapping should be considered as a partial or complete solution for physical link mapping processes. * In scenarios where active physical link mapping is not an option, physical inspection of networks is necessary to accomplish physical link mapping. This is due to the lack of reliable techniques to accurately map physical links solely through passive network traffic monitoring.
synonym: Manual Physical Link Mapping

Directory
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: may-contain
  some values from: File
type: NamedIndividual
may-contain: File
definition: In computing, a directory is a file system cataloging structure which contains references to other computer files, and possibly other directories. On many computers, directories are known as folders, or drawers to provide some relevancy to a workbench or the traditional office file cabinet.

Directory Service
type: Class
subclass of: Network Service
type: NamedIndividual
definition: In computing, directory service or name service maps the names of network resources to their respective network addresses. It is a shared information infrastructure for locating, managing, administering and organizing everyday items and network resources, which can include volumes, folders, files, printers, users, groups, devices, telephone numbers and other objects. A directory service is a critical component of a network operating system. A directory server or name server is a server which provides such a service. Each resource on the network is considered an object by the directory server. Information about a particular resource is stored as a collection of attributes associated with that resource or object.

Discovery Technique
type: Class
subclass of: ATTACK Enterprise Technique
subclass of: Offensive Technique
subclass of: Restriction
  on property: enables
  some values from: Discovery
type: NamedIndividual
enables: Discovery

Discriminant Analysis
type: Class
subclass of: Multivariate Analysis
type: NamedIndividual
d3fend-id: D3A-DA
definition: Discriminant analysis attempts to establish whether a set of variables can be used to distinguish between two or more groups of cases.
kb-article: ## References Wikipedia. (n.d.). Multivariate statistics. [Link](https://en.wikipedia.org/wiki/Multivariate_statistics)

Disk Encryption
type: Class
subclass of: Platform Hardening
subclass of: Restriction
  on property: encrypts
  some values from: Storage
type: NamedIndividual
encrypts: Storage
kb-reference: Reference-LUKS1On-DiskFormatSpecificationVersion1.2.3
d3fend-id: D3-DENCR
definition: Encrypting a hard disk partition to prevent cleartext access to a file system.

Disk Erasure
type: Class
subclass of: Disk Formatting
subclass of: Restriction
  on property: erases
  some values from: Secondary Storage
type: NamedIndividual
erases: Secondary Storage
kb-reference: Reference-Remembranceofdatapassed:Astudyofdisksanitizationpractices
d3fend-id: D3-DKE
definition: Disk Erasure is the process of securely deleting all data on a disk to ensure that it cannot be recovered by any means.
kb-article: ### How it works Disk Erasure involves overwriting the existing data with random or specific patterns multiple times. Disk erasure is crucial for data sanitization, ensuring that sensitive information is completely removed from storage devices before they are repurposed, disposed of, or transferred to another party.

Disk Formatting
type: Class
subclass of: Object Eviction
subclass of: Restriction
  on property: modifies
  some values from: Secondary Storage
type: NamedIndividual
kb-reference: Reference-Remembranceofdatapassed:Astudyofdisksanitizationpractices
modifies: Secondary Storage
d3fend-id: D3-DKF
definition: Disk Formatting is the process of preparing a data storage device, such as a hard drive, solid-state drive, or USB flash drive, for initial use.
kb-article: ### How it works This process involves setting up an empty file system on the disk, which includes creating a directory structure and initializing metadata structures. In cybersecurity, disk formatting can be used to remove all existing data on a disk, making it a clean slate for new data storage or to prevent unauthorized access to previously stored data.

Disk Image
type: Class
subclass of: Storage Image
definition: A disk image is a snapshot of a storage device's structure and data typically stored in one or more computer files on another storage device.

Disk Partitioning
type: Class
subclass of: Disk Formatting
subclass of: Restriction
  on property: creates
  some values from: Partition Table
type: NamedIndividual
creates: Partition Table
kb-reference: Reference-Remembranceofdatapassed:Astudyofdisksanitizationpractices
d3fend-id: D3-DKP
definition: Disk Partitioning is the process of dividing a disk into multiple distinct sections, known as partitions.
kb-article: ### How it works Each partition can be managed separately and can have its own file system. Disk partitioning can be used to segregate sensitive data from less critical data, improve system performance, and enhance data management and recovery processes. It can also help in isolating different operating systems or environments on the same physical disk.

Display Adapter
type: Class
subclass of: Output Device
type: NamedIndividual
definition: A graphics card (also called a display card, video card, display adapter, or graphics adapter) is an expansion card which generates a feed of output images to a display device (such as a computer monitor). Frequently, these are advertised as discrete or dedicated graphics cards, emphasizing the distinction between these and integrated graphics. At the core of both is the graphics processing unit (GPU), which is the main part that does the actual computations, but should not be confused with the video card as a whole, although "GPU" is often used to refer to video cards.
alternative label: Display Card
alternative label: Graphics Adapter
alternative label: Video Card

Display Device Driver
type: Class
subclass of: Hardware Driver
subclass of: Restriction
  on property: drives
  some values from: Display Adapter
type: NamedIndividual
drives: Display Adapter
definition: A device driver for a display adapter.

Display Server
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: A display server or window server is a program whose primary task is to coordinate the input and output of its clients to and from the rest of the operating system, the hardware, and each other. The display server communicates with its clients over the display server protocol, a communications protocol, which can be network-transparent or simply network-capable. The display server is a key component in any graphical user interface, specifically the windowing system.
alternative label: Window Server

Distribution-based Clustering
type: Class
subclass of: Cluster Analysis
type: NamedIndividual
d3fend-id: D3A-DBC
definition: Distribution-based clustering creates and groups data points based on their likely hood of belonging to the same probability distribution (Gaussian, Binomial, etc.) in the data.
kb-article: ## References AnalytixLabs. (n.d.). Types of Clustering Algorithms. [Link](https://www.analytixlabs.co.in/blog/types-of-clustering-algorithms/#:~:text=Distribution-Based)

Distribution Properties
type: Class
subclass of: Descriptive Statistics
type: NamedIndividual
d3fend-id: D3A-DP
definition: The properties derived from a probability distribution.
kb-article: ## References Wikipedia. (n.d.). Probability distribution. [Link](https://en.wikipedia.org/wiki/Probability_distribution)

Divisive Clustering
type: Class
subclass of: Hierarchical Clustering
type: NamedIndividual
d3fend-id: D3A-DC
definition: A divisive clustering approach is a hierarchical, top-down approach to clustering a dataset.

Document File
type: Class
subclass of: File
subclass of: Restriction
  on property: may-contain
  some values from: Executable Script
type: NamedIndividual
may-contain: Executable Script
definition: A document is a written, drawn, presented or recorded representation of thoughts. An electronic document file is usually used to describe a primarily textual file, along with its structure and design, such as fonts, colors and additional images.

Domain Account Monitoring
type: Class
subclass of: User Behavior Analysis
subclass of: Restriction
  on property: monitors
  some values from: Domain User Account
type: NamedIndividual
kb-reference: Reference-AuditUserAccountManagement
monitors: Domain User Account
d3fend-id: D3-DAM
definition: Monitoring the existence of or changes to Domain User Accounts.

Domain Name
type: Class
subclass of: Identifier
subclass of: Restriction
  on property: identifies
  some values from: IP Address
type: NamedIndividual
identifies: IP Address
definition: A domain name is an identification string that defines a realm of administrative autonomy, authority or control within the Internet. Domain names are formed by the rules and procedures of the Domain Name System (DNS). Any name registered in the DNS is a domain name.Domain names are used in various networking contexts and application-specific naming and addressing purposes. In general, a domain name represents an Internet Protocol (IP) resource, such as a personal computer used to access the Internet, a server computer hosting a web site, or the web site itself or any other service communicated via the Internet. In 2015, 294 million domain names had been registered.

Domain Name Reputation Analysis
type: Class
subclass of: Identifier Reputation Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Domain Name
type: NamedIndividual
analyzes: Domain Name
kb-reference: Reference-Database for receiving storing and compiling information about email messages
kb-reference: Reference-Finding phishing sites
d3fend-id: D3-DNRA
definition: Analyzing the reputation of a domain name.

Domain Registration
type: Class
subclass of: Digital Information
subclass of: Restriction
  on property: may-contain
  some values from: Domain Name
type: NamedIndividual
may-contain: Domain Name
definition: A domain registration, or domain name registration data, is the relevant registration data from Internet resources such as domain names, IP addresses, and autonomous system numbers. Registration data is typically retrieved by means of either the Registration Data Access Protocol (RDAP) or its predecessor, the WHOIS protocol.
alternative label: Domain Name Registration Data

Domain Registration Takedown
type: Class
subclass of: Object Eviction
subclass of: Restriction
  on property: deletes
  some values from: Domain Registration
type: NamedIndividual
deletes: Domain Registration
kb-reference: Reference-UnderstandingtheDomainRegistrationBehaviorofSpammers
d3fend-id: D3-DRT
definition: The process of performing a takedown of the attacker's domain registration infrastructure.
kb-article: ## How it works Most nameserver hosts and domain name registrars comply with internationally recognised standards and supply their services based on terms and conditions that provide users and organisations protection from abuse and trademark infringement. Performing a WHOIS query on the attacker's domain will provide a contact that can be notified in the case of abuse. Formal takedown processes should be initiated to suspend or disable the normal function of the domain name. ## Considerations - Takedown notifications should clearly demonstrate (with evidence) that the nameserver or registrars Terms and Conditions have been breached. - Takedown processes are notoriously slow and sometimes unsuccessful. - Many government organisations will have takedown processes that should also be followed. They may use this for intelligence to assist other organisations suffering an attack. - Top level domain registrars will have takedown processes that can be followed, as an escalation path, when the nameserver host and/or registrar have not responded or complied timeously or inline with the TLD expectations. ## Examples of Domain Registration Abuse Attackers will create infrastructure from which to carry out their operations and this may include registering domain names to be used in the various attacks. Known misuse cases include: - Registering domain names that are similar to the victim's. This is known as typosquatting or URL hijacking. Legitimate looking mails or URLs could be sent using this domain in phishing campaigns. - Registring domain names that are used in C2 beacons.

Domain Trust Policy
type: Class
subclass of: Access Policy Administration
subclass of: Restriction
  on property: restricts
  some values from: Directory Service
subclass of: Restriction
  on property: restricts
  some values from: Domain Account
type: NamedIndividual
kb-reference: Reference-HowTrustRelationshipsWorkForResourceForestsInAzureActiveDirectoryDomainServices
restricts: Directory Service
restricts: Domain Account
d3fend-id: D3-DTP
definition: Restricting inter-domain trust by modifying domain configuration.

Domain User Account
type: Class
subclass of: User Account
type: NamedIndividual
definition: A domain user account in Microsoft Windows (2000) defines that user's access to a logical group of network objects (computers, users, devices) that share the same Active Directory databases; that is, a user's access to a domain.

Driver Load Integrity Checking
type: Class
subclass of: Platform Hardening
subclass of: Restriction
  on property: authenticates
  some values from: Hardware Driver
type: NamedIndividual
authenticates: Hardware Driver
kb-reference: Reference-IntegrityAssuranceThroughEarlyLoadingInTheBootPhase CrowdstrikeInc
kb-reference: Reference-ProtectedComputingEnvironment MicrosoftTechnologyLicensingLLC
d3fend-id: D3-DLIC
definition: Ensuring the integrity of drivers loaded during initialization of the operating system.
kb-article: ## How it works This technique can be accomplished in a number of ways: * A kernel level security agent installed on a host machine ensures that the driver associated with the agent is first in the initialization order. A dependent DLL associated with the driver is configured to be processed before other dependent DLLs and executes a number of operations to ensure the driver associated with the security agent is initialized first. * Kernel components can be signed by a certificate obtained by a third party to verify the source of the component and whether it has been modified. When signed, the component will include a signature block implemented as a hash value of the component header and can also include a certificate chain. The signature and certificate data are typically added before the kernel component is distributed to the public. ## Considerations * The private keys to sign certificates as reputable companies have been stolen in the past -- in cases such as where certificates from Adobe, Realtek, and JMicron have been used to sign malicious executables. (Source: https://resources.infosecinstitute.com/cybercrime-exploits-digital-certificates/#gref) * Trusted Root Certificate Authorities have been compromised, yielding the ability to use the compromised keys to generate certificates with an arbitrary company name. * It may not be difficult for an attacker to start an organization which can obtain a signed certificate. * A root certificate authority (CA) whose certificate is trusted in the verification logic could generate incorrect certificates, if they are lax or have ulterior motives.

Dyna-Q
type: Class
subclass of: Model-based Reinforcement Learning
type: NamedIndividual
d3fend-id: D3A-DQ
definition: A Dyna-Q agent combines acting, learning, and planning.
kb-article: ## References CompNeuro Neuromatch Academy Tutorials. [Link](https://compneuro.neuromatch.io/tutorials/W3D4_ReinforcementLearning/student/W3D4_Tutorial4.html)

Dynamic Analysis
type: Class
subclass of: File Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Document File
subclass of: Restriction
  on property: analyzes
  some values from: Executable File
type: NamedIndividual
analyzes: Document File
analyzes: Executable File
kb-reference: Reference-MalwareAnalysisSystem PaloAltoNetworksInc
kb-reference: Reference-UseOfAnApplicationControllerToMonitorAndControlSoftwareFileAndApplicationEnvironments SophosLtd
d3fend-id: D3-DA
definition: Executing or opening a file in a synthetic "sandbox" environment to determine if the file is a malicious program or if the file exploits another program such as a document reader.
kb-article: ## How it works Analyzing the interaction of a piece of code with a system while the code is being executed in a controlled environment such as a sandbox, virtual machine, or simulator. This exposes the natural behavior of the piece of code without requiring the code to be disassembled. ## Considerations * Malware often detects a fake environment, then changes its behavior accordingly. For example, it could detect that the system clock is being sped up in an effort to get it to execute commands that it would normally only execute at a later time, or that the hardware manufacturer of the machine is a virtualization provider. * Malware can attempt to determine if it is being debugged, and change its behavior accordingly. * For maximum fidelity, the simulated and real environments should be as similar as possible because the malware could perform differently in different environments. * Sometimes the malware behavior is triggered only under certain conditions (on a specific system date, after a certain time, or after it is sent a specific command) and can't be detected through a short execution in a virtual environment. ## Implementations * Cuckoo Sandbox
synonym: Malware Detonation
synonym: Malware Sandbox

Dynamic Analysis Tool
type: Class
subclass of: Code Analyzer
definition: Dynamic program analysis is the analysis of computer software that is performed by executing programs on a real or virtual processor.

Email
type: Class
subclass of: Document File
subclass of: Restriction
  on property: may-contain
  some values from: File
subclass of: Restriction
  on property: may-contain
  some values from: URL
type: NamedIndividual
may-contain: File
may-contain: URL
definition: An email, or email message, is a document that is sent between computer users across computer networks.

Email Attachment
type: Class
subclass of: Document File
subclass of: Restriction
  on property: attached-to
  some values from: Email
type: NamedIndividual
attached-to: Email
definition: An email attachment is a computer file sent along with an email message. One or more files can be attached to any email message, and be sent along with it to the recipient. This is typically used as a simple method to share documents and images.

Email Event
type: Class
subclass of: Application Layer Event
subclass of: TCP Event
subclass of: Restriction
  on property: has-participant
  some values from: Mail Network Traffic
definition: An event involving email communication, including sending, receiving, and processing emails. Email events encapsulate activities essential to the transmission and analysis of email messages in a networked environment.

Email Filtering
type: Class
subclass of: Inbound Traffic Filtering
subclass of: Restriction
  on property: filters
  some values from: Email
type: NamedIndividual
filters: Email
kb-reference: Reference-SystemAndMethodForProvidingAnonymousRemailingAndFilteringOfElectronicMail Nokia
d3fend-id: D3-EF
definition: Filtering incoming email traffic based on specific criteria.
kb-article: ## How it works Mail filters can be implemented to scan inbound email messages at the initial SMTP connection stage to detect and reject email containing spam and malware. This technique is distinct from d3f:EmailDeletion because it prevents an email from reaching an user's inbox. This technique can also be used for outbound email traffic. ## Considerations * The effectiveness of mail filters depend on the completeness of the filter policies

Email Receive Event
type: Class
subclass of: Email Event
definition: An event where an email is delivered to a recipient's mail server or mailbox. This includes receiving messages from internal or external sources via protocols such as IMAP, POP3, or their secure variants.

Email Removal
type: Class
subclass of: File Eviction
subclass of: Restriction
  on property: deletes
  some values from: Email
subclass of: Restriction
  on property: may-access
  some values from: Mail Server
type: NamedIndividual
deletes: Email
kb-reference: Reference-SystemAndMethodForScanningRemoteServicesToLocateStoredObjectsWithMalware
may-access: Mail Server
d3fend-id: D3-ER
definition: The email removal technique deletes email files from system storage.
kb-article: ## How it works Email removal is a technique that can be used to prevent a user from executing malware or responding to phishing attempts. Security software or users themselves may detect malicious or suspicious email in a local or remote mail folder email and then employ this technique. ## Considerations For email that needs to be removed, an infosec organization may choose to take additional follow-up actions (such as blocking the sources or notifying providers), rather than only relying on email deletion. For the case where users detect likely suspicious email files, the organization should consider implementing a means for reporting these emails to their infosec organization. Email files may propagate through many storage systems across the an organization's systems over time, so early detection and blocking helps avoid residual, latent stores of malicous email content in the enterprise.
synonym: Email Deletion

Email Rule
type: Class
subclass of: Application Rule
type: NamedIndividual
definition: A configuration of an email application which is used to apply logical or data processing functions to data processed by the email application.

Email Scan Event
type: Class
subclass of: Email Event
definition: An event where an email is inspected or analyzed for content, security, or compliance purposes. Scanning often involves identifying spam, detecting malware, or ensuring policy adherence before delivery or after reception.

Email Send Event
type: Class
subclass of: Email Event
definition: An event where an email is transmitted from a client to a recipient via a mail server. This process often involves protocols such as SMTP or its secure variants, with potential authentication and encryption for secure delivery.

Embedded Computer
type: Class
subclass of: Client Computer
definition: An embedded computer is a computer system -- a combination of a computer processor, computer memory, and input/output peripheral devices-that has a dedicated function within a larger mechanical or electrical system. It is embedded as part of a complete device often including electrical or electronic hardware and mechanical parts. Because an embedded system typically controls physical operations of the machine that it is embedded within, it often has real-time computing constraints. Embedded systems control many devices in common use today. Ninety-eight percent of all microprocessors manufactured are used in embedded systems.
alternative label: Embedded System

Emulated File Analysis
type: Class
subclass of: File Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Document File
subclass of: Restriction
  on property: analyzes
  some values from: Executable File
type: NamedIndividual
analyzes: Document File
analyzes: Executable File
kb-reference: Reference-Network-levelPolymorphicShellcodeDetectionUsingEmulation
d3fend-id: D3-EFA
definition: Emulating instructions in a file looking for specific patterns.

Enclave
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: may-contain
  some values from: Local Area Network
type: NamedIndividual
may-contain: Local Area Network
definition: Network enclaves consist of standalone assets that do not interact with other information systems or networks. A major difference between a DMZ or demilitarized zone and a network enclave is a DMZ allows inbound and outbound traffic access, where firewall boundaries are traversed. In an enclave, firewall boundaries are not traversed. Enclave protection tools can be used to provide protection within specific security domains. These mechanisms are installed as part of an Intranet to connect networks that have similar security requirements.
alternative label: Network Enclave

Encrypted Credential
type: Class
subclass of: Credential
type: NamedIndividual
definition: A credential that is encrypted.

Encrypted Password
type: Class
subclass of: Encrypted Credential
subclass of: Password

Encrypted Tunnels
type: Class
subclass of: Network Isolation
subclass of: Restriction
  on property: isolates
  some values from: Intranet Network
type: NamedIndividual
isolates: Intranet Network
kb-reference: Reference-SecurityArchitectureForTheInternetProtocol
d3fend-id: D3-ET
definition: Encrypted encapsulation of routable network traffic.

Endpoint-based Web Server Access Mediation
type: Class
subclass of: Web Session Access Mediation
type: NamedIndividual
kb-reference: Reference-NIST-Special-Publication-800-41-Revision-1
d3fend-id: D3-EBWSAM
definition: Endpoint-based web server access mediation regulates web server access directly from user endpoints by implementing mechanisms such as client-side certificates and endpoint security software to authenticate devices and ensure compliant access.
kb-article: ## How it works Endpoint-based Web Server Access Mediation focuses on managing access to web servers directly from user devices. This involves implementing security measures like client certificates or endpoint security software to ensure that only authorized devices can initiate sessions with web servers. Examples include direct access to internal web applications from company laptops.

Endpoint Health Beacon
type: Class
subclass of: Operating System Monitoring
subclass of: Restriction
  on property: monitors
  some values from: Network Node
type: NamedIndividual
kb-reference: Reference-IntrusionDetectionUsingAHeartbeat SophosLtd
monitors: Network Node
d3fend-id: D3-EHB
definition: Monitoring the security status of an endpoint by sending periodic messages with health status, where absence of a response may indicate that the endpoint has been compromised.
kb-article: ## How it works Endpoints are configured to periodically generate and transmit a secure heartbeat that is delivered on a configured schedule and provides endpoint status information. Status information can include software details (version, configuration, etc), endpoint identification (MAC, IP address, machine ID) or other hardware/software configuration information. Interruption of the heartbeat can signal that the endpoint has been compromised. ## Considerations * Security of heartbeat messages to ensure message integrity * Disappearance of the heartbeat could simply mean that the endpoint is powered off or intentionally disconnected from the network. Therefore other criteria may need to be used to accurately detect endpoint compromise. * Attacker presence on the machine may leave the heartbeat intact. * An attacker may determine the format of the heartbeat and continue to send it even after the machine is compromised.
synonym: Endpoint Health Telemetry

Endpoint Sensor
type: Class
subclass of: Cyber Sensor
type: NamedIndividual
definition: A sensor application installed on a endpoint (platform) to collect information on platform components.

Ensemble Learning
type: Class
subclass of: Machine Learning
type: NamedIndividual
d3fend-id: D3A-EL
definition: In statistics and machine learning, ensemble methods use multiple learning algorithms to obtain better predictive performance than could be obtained from any of the constituent learning algorithms alone
kb-article: ## References Ensemble learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Ensemble_learning).

Epistemic Logic
type: Class
subclass of: Modal Logic
type: NamedIndividual
d3fend-id: D3A-EL
definition: Epistemic logic addresses modalities of knowledge; i.e., the certainty of sentences.
kb-article: ## References 1. Epistemic logic. (2023, June 4). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Modal_logic#Epistemic_logic)
synonym: Epistemic Modal Logic

Equivalence Matching
type: Class
subclass of: Logical Rules
type: NamedIndividual
d3fend-id: D3A-EM
definition: Equivalence matching is matching two values, which may be bound to variables, to see if they are equivalent.
kb-article: ## How it works Equality is a relationship between two quantities or, more generally two mathematical expressions, asserting that the quantities have the same value, or that the expressions represent the same mathematical object. Programming languages can have multiple senses of equality that may include, but are not limited to: - Identity: The objects are identical; often indicated by having values indicating the same logical address. - Equality: The values of the expessions and properties are equivalent when evaluated; they do not need to have the same logical address. ## References 1. Equality (mathematics). (2023, May 31). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Equality_(mathematics)] 2. Types of Equality. (2007, March 2). In _WikiWikiWeb_. [Link](https://wiki.c2.com/?TypesOfEquality)

Estimation
type: Class
subclass of: Inferential Statistics
type: NamedIndividual
d3fend-id: D3A-EST
definition: Estimation represents ways or a process of learning and determining the population parameter based on the model fitted to the data.
kb-article: ## References Pennsylvania State University. (n.d.). Statistical Inference and Estimation. [Link](https://online.stat.psu.edu/stat504/lesson/statistical-inference-and-estimation)

Eval Function
type: Class
subclass of: Subroutine
subclass of: Restriction
  on property: invokes
  some values from: Subroutine
type: NamedIndividual
invokes: Subroutine
definition: Takes inputs of strings and evaluations them as expressions.

Event
type: Class
subclass of: D3FEND Core

Event Log
type: Class
subclass of: Log
subclass of: Restriction
  on property: contains
  some values from: Digital Event Record
type: NamedIndividual
contains: Digital Event Record
definition: Event logs record events taking place in the execution of a system in order to provide an audit trail that can be used to understand the activity of the system and to diagnose problems. They are essential to understand the activities of complex systems, particularly in the case of applications with little user interaction (such as server applications).
synonym: Digital Event Log

Event Log Archive Event
type: Class
subclass of: Event Log Event
definition: An event involving the archiving of event log data, typically to preserve historical records in a compressed or secure format.

Event Log Clear Event
type: Class
subclass of: Event Log Event
definition: An event where the event log data is cleared from the system, often as part of log maintenance or potentially to cover tracks.

Event Log Delete Event
type: Class
subclass of: Event Log Event
definition: An event where the event log database, file, or cache is deleted from the system, removing the log's historical records.

Event Log Disable Event
type: Class
subclass of: Event Log Event
definition: An event indicating that the event logging service has been disabled, preventing it from collecting or recording logs.

Event Log Enable Event
type: Class
subclass of: Event Log Event
definition: An event where the event logging service is enabled, allowing it to actively collect and record logs.

Event Log Event
type: Class
subclass of: Digital Event
subclass of: Restriction
  on property: has-participant
  some values from: Event Log
definition: An event that captures actions or operations related to the management of system event logs, including modifications, access, and service state changes.

Event Log Export Event
type: Class
subclass of: Event Log Event
definition: An event representing the export of event log data to a file or external system for backup or analysis purposes.

Event Log Restart Event
type: Class
subclass of: Event Log Event
definition: An event representing the restarting of the event logging service, often performed during system maintenance or troubleshooting.

Event Log Rotate Event
type: Class
subclass of: Event Log Event
definition: An event where the event log is rotated, often as part of log rotation policies to manage storage and ensure continuity.

Event Log Start Event
type: Class
subclass of: Event Log Event
definition: An event where the event logging service is started, enabling the collection and recording of system events.

Event Log Stop Event
type: Class
subclass of: Event Log Event
definition: An event indicating that the event logging service has been stopped, halting the recording of system events.

Evict
type: Class
subclass of: Defensive Tactic
type: NamedIndividual
type: Defensive Tactic
definition: The eviction tactic is used to remove an adversary from a computer network.
display-order: 4
display-priority: 0

Eviction Event
type: Class
subclass of: Security Event
subclass of: Restriction
  on property: preceded-by
  some values from: Detection Event
type: NamedIndividual
related: Evict
definition: An event describing actions to remove adversaries or malicious resources from a system, re-establishing security and operational integrity.

Exact Matching
type: Class
subclass of: Equivalence Matching
subclass of: Numeric Pattern Matching
type: NamedIndividual
d3fend-id: D3A-EM
definition: Exact matching for numeric types is just the simple test for mathematical equivalence of the values being matched.
kb-article: ## References 1. Equality (mathematics). (2023, May 31). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Equality_(mathematics)]
synonym: Numeric Equivalence Matching

Exception Handler
type: Class
subclass of: Subroutine
definition: An exception handler is a code segment that processes an exception.

Exception Handler Pointer Validation
type: Class
subclass of: Application Hardening
subclass of: Restriction
  on property: validates
  some values from: Pointer
type: NamedIndividual
kb-reference: Reference-SAFESEH ImageHasSafeExceptionHandlers MicrosoftDocs
validates: Pointer
d3fend-id: D3-EHPV
definition: Validates that a referenced exception handler pointer is a valid exception handler.
kb-article: ## How It Works When a process encounters an exception, it calls an exception handler to deal with the exception. The method by which this exception handler is determined varies by the operating system. The exception handler is called, even if it is the default exception handler to terminate the program and display a message that the program stopped working. In the case that no valid exception handler is found, the program would fail to proceed as normal and could be programmed to terminate. In Windows, the address of the exception registration record is stored at the very start of the the Thread Information Block; the GS register points to this structure. The exception registration record contains two pointers: a pointer to the next exception registration record should this handler fail to handle the exception, and a pointer to the handler. A buffer overflow can overwrite the saved return pointer with an invalid location to execute memory; this often triggers the exception handler chain, which could also be corrupted by the buffer overflow. Although Process Exception Handler Validation does not make sure that the exception handler pointer or the code at the exception handler was unaltered, or that the exception handler code is secure, this technique does ensure that the pointer is at least an exception handler that could be called by the program. With Process Exception Handler Validation, before the handler is called, it checks the exception handler against a source of valid exception handlers. If the requested handler is not in this list, other techniques such as those in Process Eviction might be invoked, such as Process Termination to end the current process, or Executable Blacklisting to blacklist the potentially vulnerable or malfunctioning executable. ### Runtime valid exception handler source generation The source of valid exception handlers could be generated at runtime, with the risk of the information that is used to determine the validity of exception ha…
synonym: Exception Handler Validation

Exec
type: Class
subclass of: System Call
subclass of: Restriction
  on property: executes
  some values from: Executable Binary
type: NamedIndividual
executes: Executable Binary

Executable Allowlisting
type: Class
subclass of: Execution Isolation
subclass of: Restriction
  on property: blocks
  some values from: Executable File
subclass of: Restriction
  on property: filters
  some values from: Create Process
type: NamedIndividual
type: Platform Hardening
blocks: Executable File
filters: Create Process
kb-reference: Reference-EnhancingNetworkSecurityByPreventingUser-InitiatedMalwareExecution
kb-reference: Reference-ComputingApparatusWithAutomaticIntegrityReferenceGenerationAndMaintenance Tripwire,Inc.
d3fend-id: D3-EAL
definition: Using a digital signature to authenticate a file before opening.
kb-article: ## How it works This technique is generic and there are numerous ways to compute and authenticate digital signatures. A digital certificate is generated from a private/public key pair issued by a certificate authority (CA). A hash of the file is encrypted using the private key. When the file is downloaded by another user, the user's system uses the public key to decrypt the hash and a new hash is created of the downloaded file. The hash decrypted by the public key is compared to the new hash and if there is a mismatch, further techniques, such as file deletion, file quarantine, or **Executable Blacklisting** may be invoked. This technique may be invoked when deciding whether to execute a file. ## Considerations Organizations which download or create high volumes of software make management complex, in particular engineering or scientific organizations.
synonym: File Signature Authentication

Executable Binary
type: Class
subclass of: Executable File
subclass of: Restriction
  on property: contains
  some values from: Image Code Segment
subclass of: Restriction
  on property: contains
  some values from: Image Data Segment
subclass of: Restriction
  on property: may-interpret
  some values from: Executable Script
type: NamedIndividual
contains: Image Code Segment
contains: Image Data Segment
may-interpret: Executable Script
definition: An executable binary contains machine code instructions for a physical CPU. D3FEND also considers byte code for a virtual machine to be binary code. This is in contrast to executable scripts written in a scripting language.

Executable Denylisting
type: Class
subclass of: Execution Isolation
subclass of: Restriction
  on property: blocks
  some values from: Executable File
subclass of: Restriction
  on property: filters
  some values from: Create Process
type: NamedIndividual
blocks: Executable File
filters: Create Process
kb-reference: Reference-MethodAndApparatusForIncreasingTheSpeedAtWhichComputerVirusesAreDetected McAfeeLLC
kb-reference: Reference-ContentExtractorAndAnalysisSystem Bit9Inc,CarbonBlackInc
d3fend-id: D3-EDL
definition: Blocking the execution of files on a host in accordance with defined application policy rules.
kb-article: ## How it works #### Criteria A policy-enforcing application can register an application for denylisting based on conditions including the following: * File attributes * file name * file path * file hash * file publisher, as obtained from the digital signature * permissions of the file * File malware scan (eg. Windows SmartScreen) * User-File combination This may be done to prevent execution of applications which are: * an old version with known vulnerabilities * without a valid license, which could cause legal issues * in a directory that is accessible to low-privileged users, that could be accessed by a malware dropper * known trojan horse programs * too open in their permissions, possibly set to run as a user other than the originator or allowing execution when they should not be * a match to the hash of other known malware * are detected as undesirable based on a file scan runtime behavior System administrators will customize the rules for the given environment. #### Backend The policy-enforcing program may work by running in kernel mode, and [intercepting] [system calls which execute a process]. ## Considerations * If denylisting is done by filename, filepath, or hash, these mechanisms may be a worthy first line of defense and detection, but could still be evaded by an attacker. * Continuous management is needed to keep the denylist up to date, whether it is based on hash, publisher, behavior, or any other digital artifact. * Although denylists based on attributes such as file path and virus scan could defend against some threats which they have not been explicitly coded to block, denylists may not provide protection from new, unknown, or zero day attacks. ## Examples On a Windows machine the Windows Defender Application Control (WDAC) policy enforcement is run in the kernel and allows for restricting applications.
synonym: Executable Blacklisting

Executable File
type: Class
subclass of: File
subclass of: Restriction
  on property: contains
  some values from: Subroutine
type: NamedIndividual
contains: Subroutine
definition: In computing, executable code or an executable file or executable program, sometimes simply an executable, causes a computer "to perform indicated tasks according to encoded instructions," as opposed to a data file that must be parsed by a program to be meaningful. These instructions are traditionally machine code instructions for a physical CPU. However, in a more general sense, a file containing instructions (such as bytecode) for a software interpreter may also be considered executable; even a scripting language source file may therefore be considered executable in this sense. The exact interpretation depends upon the use; while the term often refers only to machine code files, in the context of protection against computer viruses all files which cause potentially hazardous instruction
alternative label: Executable

Executable Script
type: Class
subclass of: Executable File
type: NamedIndividual
definition: An executable script is written in a scripting language and interpreted at run time. This is in contrast with an executable binary, which contains machine code instructions for a physical CPU or byte code for a virtual machine.

Execution Isolation
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Isolate
type: NamedIndividual
enables: Isolate
d3fend-id: D3-EI
definition: Execution Isolation techniques prevent application processes from accessing non-essential system resources, such as memory, devices, or files.

Execution Technique
type: Class
subclass of: ATTACK Enterprise Technique
subclass of: Offensive Technique
subclass of: Restriction
  on property: enables
  some values from: Execution
type: NamedIndividual
enables: Execution

Exfiltration Technique
type: Class
subclass of: ATTACK Enterprise Technique
subclass of: Offensive Technique
subclass of: Restriction
  on property: enables
  some values from: Exfiltration
type: NamedIndividual
enables: Exfiltration

Expectation-maximization Clustering
type: Class
subclass of: Distribution-based Clustering
type: NamedIndividual
d3fend-id: D3A-EMC
definition: An unsupervised clustering algorithm and extends to NLP applications like Latent Dirichlet Allocation, the Baum-Welch algorithm for Hidden Markov Models, and medical imaging.
kb-article: ## References Towards Data Science. (n.d.). Expectation Maximization Explained. [Link](https://towardsdatascience.com/expectation-maximization-explained-c82f5ed438e5#:~:text=Expectation%20Maximization%20(EM)%20is%20a,Markov%20Models%2C%20and%20medical%20imaging.)

Expected Error Reduction
type: Class
subclass of: Active Learning
type: NamedIndividual
d3fend-id: D3A-EER
definition: Expected Error Reduction (EER) follows similar ideas as EMC, but again looks at the model output instead of the model itself and also takes the other data into account. In particular, a sample x is considered useful, if we can expect that knowing the label will reduce the future error on unseen samples
kb-article: ## References Intro to Active Learning. inovex Blog. [Link](https://www.inovex.de/de/blog/intro-to-active-learning/).

Expected Model Change
type: Class
subclass of: Active Learning
type: NamedIndividual
d3fend-id: D3A-EMC
definition: Supervised learning establishes a relationship between the known input and output variables to conduct a predictive analysis.
kb-article: nal Consiterations ## References Intro to Active Learning. inovex Blog. [Link](https://www.inovex.de/de/blog/intro-to-active-learning/).

External Content Inclusion Function
type: Class
subclass of: Subroutine
type: NamedIndividual
definition: External content, strings or data, are inserted into a local document (e.g. xml document) as if it were a native part of that document.

External Control
type: Class
subclass of: External Control Thing
subclass of: Restriction
  on property: member-of
  some values from: Control Catalog
subclass of: Restriction
  on property: semantic-relation
  some values from: Defensive Technique

External Control Thing
type: Class
subclass of: External Thing

External Knowledge Base
type: Class
subclass of: Technique Reference
pref-label: External Knowledge Base

External Thing
type: Class

External Threat Model Thing
type: Class
subclass of: External Thing

FTP Delete Event
type: Class
subclass of: FTP Event
definition: An event where files or directories are removed from an FTP server, resulting in their permanent deletion from the remote system.

FTP Event
type: Class
subclass of: Application Layer Event
subclass of: TCP Event
subclass of: Restriction
  on property: has-participant
  some values from: File Transfer Network Traffic
definition: An event involving the File Transfer Protocol (FTP), a standard network protocol used to transfer files between a client and server over a TCP/IP network. FTP facilitates operations such as file uploads, downloads, directory listing, and remote file management.

FTP Get Event
type: Class
subclass of: FTP Event
definition: An event where a file is downloaded from an FTP server to a client, retrieving data from the remote system to the local destination.

FTP List Event
type: Class
subclass of: FTP Event
definition: An event where the contents of a directory on an FTP server are listed, providing metadata such as file names, sizes, and timestamps.

FTP Poll Event
type: Class
subclass of: FTP Event
definition: An event where a client queries an FTP server to check for the presence of specific files or directories without initiating a transfer.

FTP Put Event
type: Class
subclass of: FTP Event
definition: An event where a file is uploaded from a client to an FTP server, transferring data from the local system to the remote destination.

FTP Rename Event
type: Class
subclass of: FTP Event
definition: An event where files or directories on an FTP server are renamed, modifying their identifiers without altering their content or location.

Fast Symbolic Link
type: Class
subclass of: Symbolic Link
subclass of: Unix Link
disjoint with: Slow Symbolic Link
definition: Fast symbolic links, allow storage of the target path within the data structures used for storing file information on disk (e.g., within the inodes). This space normally stores a list of disk block addresses allocated to a file. Thus, symlinks with short target paths are accessed quickly. Systems with fast symlinks often fall back to using the original method if the target path exceeds the available inode space.
alternative label: Fast Symlink

File
type: Class
subclass of: Resource
subclass of: Restriction
  on property: contains
  some values from: File Section
subclass of: Restriction
  on property: may-contain
  some values from: File
subclass of: Restriction
  on property: may-contain
  some values from: URL
type: NamedIndividual
contains: File Section
may-contain: URL
definition: A file maintained in computer-readable form.

File Access Event
type: Class
subclass of: File Event
definition: An event where a file is accessed for operations such as reading, opening, or inspecting its contents or metadata, without necessarily modifying its state.

File Access Pattern Analysis
type: Class
subclass of: Process Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Local Resource Access
type: NamedIndividual
analyzes: Local Resource Access
kb-reference: Reference-File-modifyingMalwareDetection CrowdstrikeInc
d3fend-id: D3-FAPA
definition: Analyzing the files accessed by a process to identify unauthorized activity.
kb-article: ## How it works File modifying malware such as wipers and ransomware are detected by identifying file access patterns that are associated with a malicious process. Examples of file access patterns include accessing a large number of files, accessing multiple file types, files being accessed located in multiple locations in a directory, and copying a file and encrypting the contents of that file into a copy. ## Considerations Certain file access actions may not be statistically different from authorized activity.

File Analysis
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: analyzes
  some values from: File
subclass of: Restriction
  on property: enables
  some values from: Detect
type: NamedIndividual
analyzes: File
enables: Detect
d3fend-id: D3-FA
definition: File Analysis is an analytic process to determine a file's status. For example: virus, trojan, benign, malicious, trusted, unauthorized, sensitive, etc.
kb-article: ## Technique Overview Some techniques use file signatures or file metadata to compare against historical collections of malware. Files may also be compared against a source of ground truth such as cryptographic signatures. Examining files for potential malware using pattern matching against file contents/file behavior. Binary code may be dissembled and analyzed for predictive malware behavior, such as API call signatures. Analysis might occur within a protected environment such as a sandbox or live system.

File Carving
type: Class
subclass of: Network Traffic Analysis
subclass of: Restriction
  on property: analyzes
  some values from: File Transfer Network Traffic
type: NamedIndividual
analyzes: File Transfer Network Traffic
kb-reference: Reference-ComputerWormDefenseSystemAndMethod FireEyeInc
d3fend-id: D3-FC
definition: Identifying and extracting files from network application protocols through the use of network stream reassembly software.
kb-article: ## How it works Protocol stream reassembly software recreates a directional byte stream by analyzing captured network packets. Once the stream is reassembled pattern matching is applied to determine if it contains a file of interest. Files of interest range from executable, archive, or document file formats. Once the file is captured, it is then processed with standard File Analysis Techniques. Example network protocols include HTTP, SMTP, FTP, HTTP/2, and TLS/HTTP/Dropbox. ## Considerations - This is an error prone process due to the intricacies of network protocols and network packet capture. For example reassembly may be done in real-time or streaming fashion, or packets may be written to disk, then bulk processed. The packets may arrive out of order, with fragmentation, duplicates, or re-transmissions. The reassembly software must compensate for the imperfect packet stream in order to recreate the well formed file which was transmitted. - File type identification can be a difficult process which can be exploited by adversaries.

File Content Analysis
type: Class
subclass of: File Analysis
type: NamedIndividual
kb-reference: Reference-CyberVaccineAndPredictiveMalwareDefensiveMethodsAndSystems
d3fend-id: D3-FCOA
definition: Employing a pattern matching algorithm to statically analyze the content of files.
kb-article: ## How it works Analyzing a piece of code without it being executed in a sandbox, virtual machine, or simulator. Patterns or signatures in the file can indicate whati kind of software it is, including whether it is malware.

File Content Rules
type: Class
subclass of: File Content Analysis
type: NamedIndividual
kb-reference: Reference-ComputationalModelingAndClassificationOfDataStreams CrowdstrikeInc
kb-reference: Reference-DetectingScript-basedMalware CrowdstrikeInc
kb-reference: Reference-DistributedMeta-informationQueryInANetwork Bit9Inc
kb-reference: Reference-SystemAndMethodsThereofForLogicalIdentificationOfMaliciousThreatsAcrossAPluralityOfEnd-pointDevicesCommunicativelyConnectedByANetwork PaloAltoNetworksIncCyberSecdoLtd
d3fend-id: D3-FCR
definition: Employing a pattern matching rule language to analyze the content of files.
kb-article: ## How it works Rules, often called signatures, are used for both generic and targeted malware detection. The rules are usually expressed in a domain specific language (DSL), then deployed to software that scans files for matches. The rules are developed and broadly distributed by commercial vendors, or they are developed and deployed by enterprise security teams to address highly targeted or custom malware. Conceptually, there are public and private rule sets. Both leverage the same technology, but they are intended to detect different types of cyber adversaries. ## Considerations * Patterns expressed in the DSLs range in their complexity. Some scanning engines support file parsing and normalization for high fidelity matching, others support only simple regular expression matching against raw file data. Engineers must make a trade-off in terms of: * The fidelity of the matching capabilities in order to balance high recall with avoiding false positives, * The computational load for scanning, and * The resilience of the engine to deal with adversarial content presented in different forms-- content which in some cases is designed to exploit or defeat the scanning engines. * Signature libraries can become large over time and impact scanning performance. * Some vendors who sell signatures have to delete old signatures over time. * Simple signatures against raw content cannot match against encoded, encrypted, or sufficiently obfuscated content. ## Implementations * YARA * ClamAV
synonym: File Content Signatures
synonym: File Signatures

File Copy Event
type: Class
subclass of: File Creation Event
definition: An event where a file is duplicated, creating a new file in a different location or under a different name while preserving the original file's content and attributes.

File Creation Analysis
type: Class
subclass of: System Call Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Create File
type: NamedIndividual
analyzes: Create File
kb-reference: Reference-LsassProcessDumpViaProcdump MITRE
kb-reference: Reference-CAR-2020-09-001:ScheduledTask-FileAccess MITRE
d3fend-id: D3-FCA
definition: Analyzing the properties of file create system call invocations.

File Creation Event
type: Class
subclass of: File Event
definition: An event representing the creation of a new file within the system, establishing its existence and initial attributes in the file system or storage medium.

File Decryption Event
type: Class
subclass of: File Event
definition: An event where a previously encrypted file is decoded, rendering its content accessible to authorized users or processes.

File Deletion Event
type: Class
subclass of: File Event
definition: An event where a file is permanently removed from the file system or storage medium, potentially triggering actions related to data retention or recovery.

File Encryption
type: Class
subclass of: Platform Hardening
subclass of: Restriction
  on property: encrypts
  some values from: File
type: NamedIndividual
encrypts: File
kb-reference: Reference-MethodForFileEncryption
d3fend-id: D3-FE
definition: Encrypting a file using a cryptographic key.
kb-article: ## How it Works Files are encrypted using either a single key for both encryption and decryption or separate keys. Single key encryption is symmetric encryption and using two key distinct keys is asymmetric encryption. ### Symmetric Cryptography Symmetric encryption uses the same cryptographic key for both the encryption and decryption a file. Managing keys at scale sometimes uses asymmetric key exchange protocols such as Diffie-Hellman can be used to share the symmetric cryptographic key with the others. ### Asymmetric Cryptography Asymmetric encryption is typically accomplished using public and private key certificates based on the X.509 standard. Files are encrypted using the public key and decrypted using their private key. Asymmetric encryption is typically slower than symmetric encryption and not widely used for large file encryption, but is popular for key wrapping, key exchanges, and digital signatures. ## Considerations - Continuous monitoring to ensure private keys are not compromised and the certificate authority (CA) is trusted. - Secure transfer of private keys between multiple devices.

File Encryption Event
type: Class
subclass of: File Event
definition: An event involving the application of cryptographic techniques to a file, ensuring its content is securely encoded and inaccessible without proper decryption keys.

File Event
type: Class
subclass of: Digital Event
subclass of: Restriction
  on property: has-participant
  some values from: File
definition: An event involving operations performed on digital files, encompassing actions such as creation, modification, deletion, access, and attribute or permission changes.

File Eviction
type: Class
subclass of: Object Eviction
subclass of: Restriction
  on property: deletes
  some values from: File
type: NamedIndividual
deletes: File
kb-reference: Reference-HowDoesAntivirusQuarantineWork-SafetyDetectives
d3fend-id: D3-FEV
definition: File eviction techniques delete files from system storage.
kb-article: ## How it works Adversaries may place files or programs into a computer's file system to perform malicious actions. As part of the eviction process, these files and programs should be removed to prevent further compromise or reinfection. Examples of malicious types of files are malware which is directly harmful and content files with the intent to deceive users (e.g., phishing.) On Windows systems, antivirus (AV) software should be used to safely and permanently remove malicious files. AV software may first quarantine a suspected malicious file, which is the process of moving a file from its original location to a new location and makes changes so that it cannot be executed. Users can then verify that the file is not benign and then permanently delete it. ## Considerations When it is determined that a file should be removed for security purposes, the organization--or systems implementing an organization's policies--may determine that the file should not simply be deleted from the enterprise's mission systems, but be quarantined to a secure system by an approved mechanism, so as to allow follow-up investigation by security staff. On Windows systems, deleting a file in File Explorer does not permanently delete a file - it sends it to the Recycle Bin instead. The Recycle Bin must be emptied, or alternative steps must be performed to remove files completely. Even then, in some cases the data may persist in disk, so data shredder tools may be needed to completely wipe a file. Thus, AV tools are recommended.

File Get Attributes Event
type: Class
subclass of: File Event
definition: An event where a file's metadata attributes, such as size, creation date, or type, are queried or retrieved without altering its content.

File Get Permissions Event
type: Class
subclass of: File Event
definition: An event where a file's security settings or access control list (ACL) is retrieved, detailing permissions granted to users or processes.

File Hash
type: Class
subclass of: Digital Fingerprint
subclass of: Restriction
  on property: identifies
  some values from: File
type: NamedIndividual
identifies: File

File Hash Reputation Analysis
type: Class
subclass of: Identifier Reputation Analysis
subclass of: Restriction
  on property: analyzes
  some values from: File Hash
type: NamedIndividual
analyzes: File Hash
kb-reference: Reference-Reputation of an entity associated with a content item
d3fend-id: D3-FHRA
definition: Analyzing the reputation of a file hash.

File Hashing
type: Class
subclass of: File Analysis
type: NamedIndividual
kb-reference: Reference-Munin
d3fend-id: D3-FH
definition: Employing file hash comparisons to detect known malware.
kb-article: ## How it works This technique requires a list of hashes to compare a file against. ## Considerations Performance on large files or very large numbers of files.

File Integrity Monitoring
type: Class
subclass of: Platform Monitoring
subclass of: Restriction
  on property: analyzes
  some values from: File
type: NamedIndividual
analyzes: File
kb-reference: Reference-FileIntegrityMonitoringinMicrosoftDefenderforCloud-Microsoft
kb-reference: Reference-Tripwire
d3fend-id: D3-FIM
definition: Detecting any suspicious changes to files in a computer system.
kb-article: ## How it Works There are a number of tools in Windows and Unix that can monitor specific files in a system and generate alerts if any artifacts have been created, modified, or removed. They accomplish this by comparing the current artifacts to a previous snapshot. Unix - Unix systems have a file integrity checker tool called tripwire. Tripwire first initializes a database that serves as a basis for comparison and can then scan the system to compare the state of the current file system against the initial baseline database. Additionally, users can define policies that specify potential violations. Windows - In Microsoft Azure, file integrity monitoring can be enabled which can track file and registry key creation, removals, and modifications of specific files. ## Considerations Files can change constantly due to the non-static nature of a computer system. File Integrity Monitoring works best when pointed at a narrow scope of critical files to limit the number of unneccessary files that may be modified over the course of normal use. The accuracy and precision of defined policies also affect the efficacy of this technique.

File Mount Event
type: Class
subclass of: File Event
definition: An event where a file system or storage volume is mounted, making its files and directories accessible to the operating system or applications.

File Path Open Function
type: Class
subclass of: Subroutine
subclass of: Restriction
  on property: accesses
  some values from: File
subclass of: Restriction
  on property: invokes
  some values from: Open File
type: NamedIndividual
accesses: File
invokes: Open File
definition: Has an input of a file path, and opens a file handle for reading or writing.

File Renaming Event
type: Class
subclass of: File Event
definition: An event representing the renaming of a file, modifying its identifier within the file system while retaining its content and metadata.

File Section
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: A file section is one of the portions of a file in which the file is regarded as divided and where together the file sections constitute the whole file.
alternative label: File Part

File Server
type: Class
subclass of: Server
definition: The term server highlights the role of the machine in the traditional client-server scheme, where the clients are the workstations using the storage. A file server does not normally perform computational tasks or run programs on behalf of its client workstations. File servers are commonly found in schools and offices, where users use a local area network to connect their client computers.

File Set Attributes Event
type: Class
subclass of: File Event
definition: An event where a file's metadata attributes are modified, such as changing its timestamps, labels, or categorization within the system.

File Set Permissions Event
type: Class
subclass of: File Event
definition: An event involving the modification of a file's permissions or access control list (ACL), specifying which users or processes are granted or restricted access.

File Share Service
type: Class
subclass of: Network Service
definition: A file sharing service (or file share service) provides the ability to share data across a network.

File System
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: contains
  some values from: Directory
subclass of: Restriction
  on property: contains
  some values from: File
subclass of: Restriction
  on property: contains
  some values from: File System Link
subclass of: Restriction
  on property: contains
  some values from: File System Metadata
type: NamedIndividual
contains: Directory
contains: File
contains: File System Link
contains: File System Metadata
definition: In computing, a file system or filesystem is used to control how data is stored and retrieved. Without a file system, information placed in a storage medium would be one large body of data with no way to tell where one piece of information stops and the next begins. By separating the data into pieces and giving each piece a name, the information is easily isolated and identified. Taking its name from the way paper-based information systems are named, each group of data is called a "file". The structure and logic rules used to manage the groups of information and their names is called a "file system".

File System Link
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: A file system link associates a name with a file on a file system. Most generally, this may be a direct reference (a hard link) or an indirect one (a soft link).

File System Metadata
type: Class
subclass of: Metadata
type: NamedIndividual
definition: Metadata about the files and directories in a file system. For example file name, file length, time modified, group and user ids, and other file attributes.

File System Sensor
type: Class
subclass of: Endpoint Sensor
subclass of: Restriction
  on property: monitors
  some values from: File
type: NamedIndividual
monitors: File
definition: Collects files and file metadata on an endpoint.

File Transfer Network Traffic
type: Class
subclass of: Network Traffic
type: NamedIndividual
definition: File transfer network traffic is network traffic related to file transfers between network nodes. This includes only network traffic conforming to standard file transfer protocols, not custom transfer protocols.

File Unmount Event
type: Class
subclass of: File Event
definition: An event where a file system or storage volume is unmounted, disconnecting its files and directories from the operating system or applications.

File Update Event
type: Class
subclass of: File Event
definition: An event involving changes to the content or metadata of an existing file, reflecting updates that alter its state or properties.

Finger Print Scanner Input Device
type: Class
subclass of: Image Scanner Input Device
definition: A fingerprint sensor is an electronic device used to capture a digital image of the fingerprint pattern. The captured image is called a live scan. This live scan is digitally processed to create a biometric template (a collection of extracted features) which is stored and used for matching. Many technologies have been used including optical, capacitive, RF, thermal, piezoresistive, ultrasonic, piezoelectric, and MEMS.
alternative label: Fingerprint Sensor

Firewall
type: Class
subclass of: Computer Network Node
type: NamedIndividual
definition: In computing, a firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. A firewall typically establishes a barrier between a trusted internal network and untrusted external network, such as the Internet. Firewalls are often categorized as either network firewalls or host-based firewalls. Network firewalls filter traffic between two or more networks and run on network hardware. Host-based firewalls run on host computers and control network traffic in and out of those machines. This definition refers to network firewalls.
alternative label: Network Firewall

Firmware
type: Class
subclass of: Software
type: NamedIndividual
definition: In electronic systems and computing, firmware is a type of software that provides control, monitoring and data manipulation of engineered products and systems. Typical examples of devices containing firmware are embedded systems (such as traffic lights, consumer appliances, remote controls and digital watches), computers, computer peripherals, mobile phones, and digital cameras. The firmware contained in these devices provides the low-level control program for the device.

Firmware Behavior Analysis
type: Class
subclass of: Platform Monitoring
subclass of: Restriction
  on property: analyzes
  some values from: Firmware
type: NamedIndividual
analyzes: Firmware
kb-reference: Reference-FirmwareBehaviorAnalysisConFirm
kb-reference: Reference-FirmwareBehaviorAnalysisVIPER
d3fend-id: D3-FBA
definition: Analyzing the behavior of embedded code in firmware and looking for anomalous behavior and suspicious activity.
kb-article: ## How it works Firmware behavior analysis provides protections by ensuring that installed firmware has not been tampered with or modified. Firmware analysis applies to mutable firmware and immutable read-only memory (ROMs). Firmware in deployed network devices is typically not analyzed and monitored for vulnerabilities and thus is subject to potential attacks. This technique makes use of known and measured behavioral attributes, including timing attributes, of analyzed firmware on deployed devices. A behavioral method that employs known timing measurements may use the timing results from a challenge and response protocol to detect the presence of malware in embedded firmware. Firmware device timing measurements are made, specific to the installed device, and are used in the verifying function. The original firmware image is modified by injecting a monitoring software component into the embedded firmware code. The injected software components will allow for a software root of trust, the challenge and response protocol, to be implement in the firmware. A challenge-response is issued and includes a nonce so that replays are not allowed. The firmware will calculate a checksum over all of memory, including the nonce, and return the result. The verification system will compare the computed checksum and the time it took for the computation of the checksum to determine if the firmware has been modified. ## Considerations * The firmware code will need to be modified to include the behavioral monitoring functionality. * This technique is sensitive to the device the embedded firmware is hosted on and it is expected that the devices and firmware will need to be profiled and analyzed to determine timing estimation. * This technique is not expected to be one hundred percent correct as you would expect in a hardware root of trust solution and may require some tuning.
synonym: Firmware Timing Analysis

Firmware Embedded Monitoring Code
type: Class
subclass of: Platform Monitoring
subclass of: Restriction
  on property: analyzes
  some values from: Firmware
type: NamedIndividual
analyzes: Firmware
kb-reference: Reference-FirmwareEmbeddedMonitoringCodeRedBalloon
kb-reference: Reference-FirmwareEmbeddedMonitoringCodeSymbiotes
d3fend-id: D3-FEMC
definition: Monitoring code is injected into firmware for integrity monitoring of firmware and firmware data.
kb-article: ## How it works Firmware in deployed network devices is typically not monitored for malicious changes. This technique provides a method to embed a software security component into the deployed firmware which provides a near real-time monitoring hook. The exception handling code, in the firmware, is typically used to expose any detected vulnerabilities. The injected software components provide a feature similar to intrusion detection systems for the firmware by detecting unauthorized modifications of the embedded firmware. The integrity of static code and firmware data are monitored continuously in the hosted devices. Comparisons are made to monitored elements like firmware memory addresses and data segments. Memory pages are scanned and if a modification is detected the software component may lock the page. This will protect subsequent attempted modifications to the firmware. The software component may utilize the exception handling code and thus be able to disclose the exact address of the modified memory. The injected software components are inserted during the firmware imaging process. The injected software is assumed to have knowledge of both the embedded code and the current execution state of the host program. The injected software will monitor and alert, in near real-time, on potential suspicious activity. The injected code is run alongside of the embedded code in the host. The injected software operates as an independent entity and is not dependent on the host software. Finally, this technique may implement other countermeasure techniques as part of their analytical processes. These should be identified by referencing other countermeasure techniques directly as necessary. ## Considerations * The firmware code will need to be modified and re-hosted on the device. * Exposing monitoring hooks to the injected code may introduce additional risk.

Firmware Sensor
type: Class
subclass of: Endpoint Sensor
subclass of: Restriction
  on property: monitors
  some values from: Firmware
type: NamedIndividual
monitors: Firmware
definition: Collects information on firmware installed on an Endpoint.

Firmware Verification
type: Class
subclass of: Platform Monitoring
subclass of: Restriction
  on property: verifies
  some values from: Firmware
type: NamedIndividual
kb-reference: Reference-FirmwareVerificationEclypsium
kb-reference: Reference-FirmwareVerificationTrapezoid
kb-reference: Reference-PlatformFirmwareResiliencyGuidelines NIST
verifies: Firmware
d3fend-id: D3-FV
definition: Cryptographically verifying firmware integrity.
kb-article: ## How it works Cryptographic hash values are computed for system and peripheral firmware. The hash values are compared against precomputed hash values for the identified firmware. A hash value mismatch may indicate that the firmware may have been tampered with or updated with a non-current release indicating a misconfiguration for the system. ## Considerations * Requires cryptographically computed hash values of firmware * Requires storage of precomputed firmware hash values

First-order Logic
type: Class
subclass of: Predicate Logic
type: NamedIndividual
d3fend-id: D3A-FOL
definition: First-order logic is a collection of formal systems used in mathematics, philosophy, linguistics, and computer science. First-order logic uses quantified variables over non-logical objects, and allows the use of sentences that contain variables.
kb-article: ## How it works For propositions such as "Socrates is a man", one can have expressions in the form "there exists x such that x is Socrates and x is a man", where "there exists" is a quantifier, while x is a variable. This distinguishes it from propositional logic, which does not use quantifiers or relations. The term "first-order" distinguishes first-order logic from higher-order logic, in which there are predicates having predicates or functions as arguments, or in which quantification over predicates, functions, or both, are permitted. ## Considerations - Advantages: -- First-order logic is more expressive than propositional logic; one can talk about objects and their properties, relations between objects. -- First-order logic is able to make use of variables and quantifiers (e.g., "for all" and "exists".) -- First-order logic supports power forms of reasoning, such as inferring the properties of an unknown object from the properties of known objects. - Disadvantages: -- First-order logic is more difficult to learn and use than propositional logic, due to its greater complexity. -- First-order logic is also less tractable than propositional logic in many cases; reasoning about quantifiers and variables adds complexity. -- First-order logic can be difficult to apply in practice, due to the need to find appropriate axioms and rules for each application. ### Verification Approach - Automated theorem provers can assist in formal verification, performing automated reasoning over system modeled in first-order logic and explore a complete space of system behaviors - First-order logic may be more expressive than necessary for many types of problems and may be more difficult to verify by SMEs. - Theorem provers based in FOL are capable of use in software verification tasks, but an SMT solver such as Z3 might be more appropriate. - Defining a set of competency questions (i.e., query use cases for a first-order logic ontology) can help scope the logic required for a complete…
synonym: FOL
synonym: First-order Predicate Calculus
synonym: Quantificational Logic

First-stage Boot Loader
type: Class
subclass of: Boot Loader
definition: The very first routine run in order to load the operating system.

Flash Memory
type: Class
subclass of: Secondary Storage
definition: Flash memory is an electronic non-volatile computer memory storage medium that can be electrically erased and reprogrammed.

Forecasting
type: Class
subclass of: Analytical Purpose

Forward Proxy Server
type: Class
subclass of: Proxy Server
definition: An forward (or open) proxy is a proxy server that is accessible by any Internet user. Generally, a proxy server only allows users within a network group (i.e. a closed proxy) to store and forward Internet services such as DNS or web pages to reduce and control the bandwidth used by the group. With an open proxy, however, any user on the Internet is able to use this forwarding service.

Forward Resolution Domain Denylisting
type: Class
subclass of: DNS Denylisting
subclass of: Restriction
  on property: blocks
  some values from: Outbound Internet DNS Lookup Traffic
type: NamedIndividual
blocks: Outbound Internet DNS Lookup Traffic
kb-reference: Reference-UseDNSPolicyForApplyingFiltersOnDNSQueries
d3fend-id: D3-FRDDL
definition: Blocking a lookup based on the query's domain name value.
kb-article: ## How it works Policies are created that filter DNS queries using fully qualified domain name (FQDN) of record in the query. A DNS policy can be created for blocking DNS queries from FQDNs that have been identified as unauthorized. ## Considerations Continuous maintenance of unauthorized domain lists is needed to keep up to date as updates occur.
synonym: Forward Resolution Domain Blacklisting

Forward Resolution IP Denylisting
type: Class
subclass of: DNS Denylisting
subclass of: Restriction
  on property: blocks
  some values from: Inbound Internet DNS Response Traffic
type: NamedIndividual
blocks: Inbound Internet DNS Response Traffic
kb-reference: Reference-UseDNSPolicyForApplyingFiltersOnDNSQueries
d3fend-id: D3-FRIDL
definition: Blocking a DNS lookup's answer's IP address value.
kb-article: ## How it works This technique prevents a client from learning IP addresses deemed to be potentially malicious, which would have been delivered via forward resolution responses. Responses to forward resolution requests (that is, requests where a domain is sent and IP(s) are returned) are collected, and the IP address(es) included as a response are examined. If the IP address(es) are in a range included in the blacklist, then the response is dropped and not forwarded to the client. The DNS lookup can be blocked by either dropping the network traffic with an inline device, or modifying the value of the response sent by the DNS server. To transparently prevent client applications from hanging on a request, it is common practice to replace malicious values with addresses in the range 127.0.0.0/8 or the address of a honeypot maintained by the network administrators. ## Considerations * This technique does not prevent the client from contacting the blacklisted IP, only from learning about this IP address via a nameserver lookup request. * DNS Response traffic can be transmitted over many different protocols, which presents a challenge to implementing methods to extract all DNS answer IP address value(s). * DNS has historically used UDP port 53, with TCP port 53 instead used for responses over 512 bytes or after a lack of response over UDP. * Usage of new protocols to provide confidentiality for DNS traffic, such as DoH (DNS over HTTPS) and DoT (DNS over TLS), complicates collection of the IP address(es) in DNS responses. These protocols have often been enabled in browser settings transparently after a browser update, with DNS requests proxied over one of these cryptographic protocols through a specified host. * This technique must be implemented logically between the application that receives the response and the server which sent the response. * DNS responses sent in an encrypted manner, such as those using DoH or DoT, will require interception of the TLS connections in …
synonym: Forward Resolution IP Blacklisting

Free Memory
type: Class
subclass of: System Call
subclass of: Restriction
  on property: deletes
  some values from: Memory Block
type: NamedIndividual
deletes: Memory Block

Full Volume Snapshot
type: Class
subclass of: Volume Snapshot
definition: A full volume snapshot is a point-in-time copy of the complete contents of a volume.

Fuzzy Logic
type: Class
subclass of: Symbolic AI
type: NamedIndividual
d3fend-id: D3A-FL
definition: Fuzzy logic is a form of many-valued logic in which the truth value of variables may be any real number between 0 and 1.
kb-article: ## How it works It is employed to handle the concept of partial truth, where the truth value may range between completely true and completely false.[1] By contrast, in Boolean logic, the truth values of variables may only be the integer values 0 or 1. ## References 1. Fuzzy logic. (2023, May 28). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Fuzzy_logic)

GPT
type: Class
subclass of: Transformer-based Learning
type: NamedIndividual
d3fend-id: D3A-GPT
definition: Generative pre-trained transformers (GPT) are a type of large language model (LLM) and a prominent framework for generative artificial intelligence.
kb-article: ## References Generative pre-trained transformer. (n.d.). In Wikipedia. [Link](https://en.wikipedia.org/wiki/Generative_pre-trained_transformer)
synonym: Generative Pre-trained Transformer

Gated Recurrent Unit
type: Class
subclass of: Recurrent Neural Network
type: NamedIndividual
d3fend-id: D3A-GRU
definition: The GRU is like a long short-term memory (LSTM) with a forget gate, but has fewer parameters than LSTM, as it lacks an output gate. GRU's performance on certain tasks of polyphonic music modeling, speech signal modeling and natural language processing was found to be similar to that of LSTM
kb-article: ## References Wikipedia. (2021, September 20). Gated Recurrent Unit. [Link](https://en.wikipedia.org/wiki/Gated_recurrent_unit)

Media Generation
type: Class
subclass of: Analytical Purpose

Generative Adversarial Network
type: Class
subclass of: Unsupervised Learning
type: NamedIndividual
d3fend-id: D3A-GAN
definition: Generative Adversarial Networks (GAN) are an approach to generative modeling using deep learning methods, such as convolutional neural networks.
kb-article: ## References Brownlee, J. (2019). What Are Generative Adversarial Networks (GANs)? Machine Learning Mastery. [Link](https://machinelearningmastery.com/what-are-generative-adversarial-networks-gans/)
synonym: GAN

Geometric Mean
type: Class
subclass of: Central Tendency
type: NamedIndividual
d3fend-id: D3A-GM
definition: The nth root of the product of the data values, where there are n of these. This measure is valid only for data that are measured absolutely on a strictly positive scale.
kb-article: ## References Wikipedia. (n.d.). Central tendency. [Link](https://en.wikipedia.org/wiki/Central_tendency)

Get Open Sockets
type: Class
subclass of: System Call
subclass of: Restriction
  on property: enumerates
  some values from: Pipe
type: NamedIndividual
enumerates: Pipe

Get Open Windows
type: Class
subclass of: System Call
type: NamedIndividual

Get Running Processes
type: Class
subclass of: System Call
subclass of: Restriction
  on property: enumerates
  some values from: Process
type: NamedIndividual
enumerates: Process

Get Screen Capture
type: Class
subclass of: System Call
type: NamedIndividual

Get System Config Value
type: Class
subclass of: System Config System Call
subclass of: Restriction
  on property: reads
  some values from: System Configuration Database Record
type: NamedIndividual
reads: System Configuration Database Record

Get System Network Config Value
type: Class
subclass of: Get System Config Value
type: NamedIndividual

Get System Time
type: Class
subclass of: System Call
type: NamedIndividual
definition: A system call that gets the system time. For POSIX.1 systems, time() invokes a call to get the system time.

Get Thread Context
type: Class
subclass of: System Call
subclass of: Restriction
  on property: queries
  some values from: Thread
type: NamedIndividual
queries: Thread

Global User Account
type: Class
subclass of: Domain User Account
type: NamedIndividual
definition: A type of user account in Microsoft Windows (NT) that has a domain-wide scope.defines that user's access to a logical group of network objects (computers, users, devices) that share the same Active Directory databases; that is, a user's access to the domain.

Goal
type: Class
subclass of: D3FEND Core

Goodman and Kruskal's Gamma
type: Class
subclass of: Rank Correlation
type: NamedIndividual
d3fend-id: D3A-GAKG
definition: Goodman-Kruskal $\\gamma$ is a measure of rank correlation between x and y and is given by $(n_c -n_d) / (n_c + n_d)$, where $n_c$ is the number of concordant pairs of the observations and $n_d$ is the number of discordant pairs.
kb-article: ## References 1. Wolfram Research. (2012). GoodmanKruskalGamma. Wolfram Language function. [Link](https://reference.wolfram.com/language/ref/GoodmanKruskalGamma.html) 1. Goodman and Kruskal's gamma. (2022, Nov 23). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Goodman_and_Kruskal%27s_gamma]

Gradient-Boosted Decision Tree
type: Class
subclass of: CART
type: NamedIndividual
d3fend-id: D3A-GBDT
definition: A gradient-boosted decision tree is, as in other bagging and boosting methods, a method where the relatively 'weak' machine learning model (a decision tree) is used in an ensemble to form a 'strong' machine learning model.
kb-article: ## Reference 1. Google. (28 Sep 2023). Gradient Boosted Decision Trees. [Link](https://developers.google.com/machine-learning/decision-forests/intro-to-gbdt).

Graph-based Clustering
type: Class
subclass of: Cluster Analysis
type: NamedIndividual
d3fend-id: D3A-GBC
definition: Graph-based Clustering is a form of clustering where data is represented with graphs to identify clusters. We include Connection-based Clustering in this class.
kb-article: ## References 1. Jagota, A. (13 Dec 2020). Density-based and Graph-based Clustering. towardsdatascience.com. [Link](https://towardsdatascience.com/density-based-and-graph-based-clustering-a1f0d45ff5fb) 1. Connectivity-Based Clustering. Sarang, P. (2023) in Thinking Data Science. The Springer Series in Applied Machine Learning. Springer, Cham. [Link](https://doi.org/10.1007/978-3-031-02363-7_10).
synonym: Connection-based Clustering

Graph-based Semi-supervised Learning
type: Class
subclass of: Semi-supervised Transductive Learning
type: NamedIndividual
d3fend-id: D3A-GBSSL
definition: Graph-based Semi-Supervised Learning (GSSL) methods aim to classify unlabeled data by learning the graph structure and labeled data jointly.
kb-article: ## References Yang, S., Pan, L., & Cheng, J. (2021). Graph-based Semi-Supervised Learning Methods for Imbalanced Data Classification. [Link](https://www.sciencedirect.com/science/article/pii/S0031320321002132?viewFullText=true).

Graphical User Interface
type: Class
subclass of: User Interface
type: NamedIndividual
definition: A graphical user interface (GUI) is a type of user interface that allows users to interact with electronic devices through graphical icons and visual indicators such as secondary notation, instead of text-based user interfaces, typed command labels or text navigation. GUIs were introduced in reaction to the perceived steep learning curve of command-line interfaces (CLIs), which require commands to be typed on a computer keyboard.
alternative label: GUI

Graphics Card Firmware
type: Class
subclass of: Peripheral Firmware
definition: Firmware that is installed on computer graphics card.
alternative label: Video Card Firmware

Graphics Processing Unit
type: Class
subclass of: Processor
synonym: GPU

Grid-CNN
type: Class
subclass of: Convolutional Neural Network
type: NamedIndividual
d3fend-id: D3A-GC
definition: A class of neural networks that specializes in processing data that has a grid-like topology, such as an image.
kb-article: ## References Talukdar, P. (2020, June 10). Convolutional Neural Networks Explained. Towards Data Science. [Link](https://towardsdatascience.com/convolutional-neural-networks-explained-9cc5188c4939)

Grid-based Clustering
type: Class
subclass of: High-dimension Clustering
type: NamedIndividual
d3fend-id: D3A-GBC
definition: Divides the entire data space into a finite number of cells reducing the complexity of the data and focuses on the cells rather than the data.
kb-article: ## References TechVidvan. (n.d.). Clustering in Machine Learning Tutorial. [Link](https://techvidvan.com/tutorials/clustering-in-machine-learning/)

Group
type: Class
subclass of: D3FEND Core

Group Creation Event
type: Class
subclass of: Group Management Event
definition: An event where a new group is established within the system, defining an entity to manage users and permissions collectively.

Group Deletion Event
type: Class
subclass of: Group Management Event
definition: An event where an existing group is permanently removed from the system, dissolving its associated memberships and privileges.

Group Management Event
type: Class
subclass of: Digital Event
subclass of: Restriction
  on property: has-participant
  some values from: Access Control Group
definition: An event involving the creation, modification, or deletion of a group, or changes to its membership and privileges. Group management events facilitate the enforcement of role-based access control by organizing users and permissions into logical units for streamlined administration and policy enforcement.

Group Policy
type: Class
subclass of: Access Control Configuration
type: NamedIndividual
definition: Group Policy is a feature of the Microsoft Windows NT family of operating systems that controls the working environment of user accounts and computer accounts. Group Policy provides the centralized management and configuration of operating systems, applications, and users' settings in an Active Directory environment. A version of Group Policy called Local Group Policy ("LGPO" or "LocalGPO") also allows Group Policy Object management on standalone and non-domain computers.

Grouping
type: Class
subclass of: Summarizing

Guideline Reference
type: Class
subclass of: Policy Reference
pref-label: Guideline

HTML File
type: Class
subclass of: Document File
definition: A document file encoded in HTML.The HyperText Markup Language, or HTML is the standard markup language for documents designed to be displayed in a web browser. It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScript. Web browsers receive HTML documents from a web server or from local storage and render the documents into multimedia web pages. HTML describes the structure of a web page semantically and originally included cues for the appearance of the document.

HTTP CONNECT Event
type: Class
subclass of: HTTP Request Event
definition: An event where the HTTP CONNECT method is used to establish a tunnel to the server identified by the target resource.

HTTP DELETE Event
type: Class
subclass of: HTTP Request Event
definition: An event where the HTTP DELETE method is used to delete the specified resource.

HTTP Event
type: Class
subclass of: Application Layer Event
subclass of: TCP Event
subclass of: Restriction
  on property: has-participant
  some values from: Web Network Traffic
definition: An event involving the Hypertext Transfer Protocol (HTTP), which operates over TCP to transmit hypermedia documents.

HTTP GET Event
type: Class
subclass of: HTTP Request Event
definition: An event where the HTTP GET method is used to request a representation of the specified resource.

HTTP HEAD Event
type: Class
subclass of: HTTP Request Event
definition: An event where the HTTP HEAD method is used to request metadata about the specified resource without the response body.

HTTP OPTIONS Event
type: Class
subclass of: HTTP Request Event
definition: An event where the HTTP OPTIONS method is used to describe the communication options for the target resource.

HTTP POST Event
type: Class
subclass of: HTTP Request Event
definition: An event where the HTTP POST method is used to submit data to the specified resource, often causing a change in state or side effects on the server.

HTTP PUT Event
type: Class
subclass of: HTTP Request Event
definition: An event where the HTTP PUT method is used to replace all current representations of the target resource with the request payload.

HTTP Request Event
type: Class
subclass of: HTTP Event
definition: An event where an HTTP request is sent from a client to a server over an established TCP connection.

HTTP Response Event
type: Class
subclass of: HTTP Event
definition: An event where an HTTP response is sent from a server to a client over an established TCP connection.

HTTP TRACE Event
type: Class
subclass of: HTTP Request Event
definition: An event where the HTTP TRACE method is used to perform a message loop-back test along the path to the target resource.

Hard Disk Firmware
type: Class
subclass of: Peripheral Firmware
definition: Firmware that is installed on a hard disk device.
alternative label: Hard Drive Firmware

Hard Link
type: Class
subclass of: File System Link
definition: In computing, a hard link is a directory entry that associates a name with a file on a file system. All directory-based file systems must have at least one hard link giving the original name for each file. The term "hard link" is usually only used in file systems that allow more than one hard link for the same file. Multiple hard links -- that is, multiple directory entries to the same file -- are supported by POSIX-compliant and partially POSIX-compliant operating systems, such as Linux, Android, macOS, and also Windows NT4 and later Windows NT operating systems.

Harden
type: Class
subclass of: Defensive Tactic
type: NamedIndividual
type: Defensive Tactic
definition: The harden tactic is used to increase the opportunity cost of computer network exploitation. Hardening differs from Detection in that it generally is conducted before a system is online and operational.
display-order: 0
display-priority: 0

Hardening Event
type: Class
subclass of: Security Event
type: NamedIndividual
related: Harden
definition: An event involving actions to strengthen defenses, such as applying patches or implementing secure configurations, reducing attack surfaces, and increasing the difficulty of exploitation by adversaries.

Hardware-based Process Isolation
type: Class
subclass of: Execution Isolation
subclass of: Restriction
  on property: isolates
  some values from: Process
subclass of: Restriction
  on property: restricts
  some values from: Create Process
type: NamedIndividual
isolates: Process
kb-reference: Reference-VirtualizedProcessIsolation AdvancedMicroDevicesInc
kb-reference: Reference-ApproachesForSecuringAnInternetEndpointUsingFine-grainedOperatingSystemVirtualization Bromium,Inc.
kb-reference: Reference-IsolationOfApplicationsWithinAVirtualMachine Bromium,Inc.
restricts: Create Process
d3fend-id: D3-HBPI
definition: Preventing one process from writing to the memory space of another process through hardware based address manager implementations.
kb-article: ## How it works Process isolation, in this context, is address space separation controlled by a security function that limits the communication between processes so that one process cannot directly modify the executing code of another process. For example with virtual address space: * Process A address space is different from process B address space, which prevents process A from writing to process B Hardware process isolation is commonly implemented through Direct Memory Access (DMA) which collaborates with a Memory Management Unit (MMU), or Input-Output Memory Management Unit (IOMMU). These hardware controls are deployed directly on processors to aid hosts or enclaves in process isolation. * DMA - Direct memory access allows memory access to occur independently of the program currently run by the microprocessor. DMA allows for I/O devices to directly read from and write to memory, or it can be used to efficiently copy blocks of memory. During DMA transfers, the microprocessor can execute an unrelated program. * MMU - A memory management unit acts as an access control and is responsible for performing the translation of virtual memory addresses to physical memory addresses. The MMU allocates each process its own virtual memory space. * IOMMU - An input-output memory management unit is used to allocate each I/O device its own virtual address space to the underlying physical addresses. IOMMU allows devices that do not support long memory addresses to address the entire memory space. ## Considerations * Private hosts may be vulnerable to DMA attack if they have a PCI or PCI Express port that connects attached devices directly to physical address space. ## Implementations: * Intel Virtualization Technology for Directed I/O (Intel VT-d) * Firecracker
synonym: Virtualization

Hardware Component Inventory
type: Class
subclass of: Asset Inventory
subclass of: Restriction
  on property: inventories
  some values from: Hardware Device
type: NamedIndividual
inventories: Hardware Device
kb-reference: Reference-AdvancedDeviceMatchingSystem
d3fend-id: D3-HCI
definition: Hardware component inventorying identifies and records the hardware items in the organization's architecture.
kb-article: ## How it works Administrators collect information on hardware devices such as peripherals, NICs, processors, and memory devices that are components of the computers in their architecture using a variety of administrative and management tools that query for this information. In some cases, where such queries are not supported or provide specific information of interest, an administrator may also collect this information through remote adminstration tools and system commands, either manually or using scripts. ## Considerations * Scanning and probing techniques using mapping tools can result in side effects to information technology (IT) and operational technology (OT) systems. * An adversary conducting network enumeration may engage in activities that parallel normal hardware inventorying activities, but would require escalating to admin privileges for most of the operations requiting administrative tools ## Examples * Bus discovery * Admin-scripted PCI Bus inventory using ssh and pciutils * Application-layer discovery * Simple Network Management Protocol (SNMP) collects MIB information * Web-based Enterprise Management (WBEM) collects CIM information * Windows Management Instrumentation (WMI) * Windows Management Infrastructure (MI)
synonym: Hardware Component Discovery
synonym: Hardware Component Inventorying

Hardware Device
type: Class
subclass of: Digital Information Bearer
subclass of: Physical Artifact
type: NamedIndividual
definition: Hardware devices are the physical artifacts that constitute a network or computer system. Hardware devices are the physical parts or components of a computer, such as the monitor, keyboard, computer data storage, hard disk drive (HDD), graphic cards, sound cards, memory (RAM), motherboard, and so on, all of which are tangible physical objects. By contrast, software is instructions that can be stored and run by hardware. Hardware is directed by the software to execute any command or instruction. A combination of hardware and software forms a usable computing system.

Hardware Device Bind Event
type: Class
subclass of: Hardware Device State Event
definition: An event where a device is logically bound to a system or process, typically for exclusive use or integration with specific software components.

Hardware Device Connection Event
type: Class
subclass of: Hardware Device State Event
definition: An event representing the physical or logical attachment of a device to a system, enabling its operational functionality.

Hardware Device Disabled Event
type: Class
subclass of: Hardware Device State Event
definition: An event where a device transitions to an inactive or unavailable state, often due to deactivation, failure, or maintenance.

Hardware Device Disconnection Event
type: Class
subclass of: Hardware Device State Event
definition: An event representing the removal of a device from a system, ceasing its operational functionality or availability.

Hardware Device Enabled Event
type: Class
subclass of: Hardware Device State Event
definition: An event where a device becomes operational and available for use, typically following initialization, activation, or repair.

Hardware Device Event
type: Class
subclass of: Digital Event
subclass of: Restriction
  on property: has-participant
  some values from: Hardware Device
definition: An event capturing the existence, state, or interaction of hardware or virtual devices within a system. Device events encompass activities such as discovery, connection, disconnection, operational state changes, or configuration modifications, providing visibility into device behavior and health.

Hardware Device Move Event
type: Class
subclass of: Hardware Device State Event
definition: An event where a device is relocated or reassigned within a system or network, potentially affecting its operational scope or connectivity.

Hardware Device State Event
type: Class
subclass of: Hardware Device Event
definition: An event involving a change to a device's state, such as connection, disconnection, modification, or operational state transitions (e.g., online or offline). Device state events provide visibility into device availability and operational conditions.

Hardware Device Unbind Event
type: Class
subclass of: Hardware Device State Event
definition: An event where a device is logically unbound from a system or process, releasing it from exclusive use or integration.

Hardware Device Update Event
type: Class
subclass of: Hardware Device State Event
definition: An event capturing updates or changes to a device's configuration, properties, or state, including firmware updates, reconfigurations, or optimizations.

Hardware Driver
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: drives
  some values from: Hardware Device
type: NamedIndividual
drives: Hardware Device
definition: In computing, a device driver (commonly referred to simply as a driver) is a computer program that operates or controls a particular type of device that is attached to a computer. A driver provides a software interface to hardware devices, enabling operating systems and other computer programs to access hardware functions without needing to know precise details of the hardware being used. A driver communicates with the device through the computer bus or communications subsystem to which the hardware connects. When a calling program invokes a routine in the driver, the driver issues commands to the device. Once the device sends data back to the driver, the driver may invoke routines in the original calling program. Drivers are hardware dependent and operating-system-specific. They usually provide the interrupt handling required for any necessary asynchronous time-dependent hardware interface.
alternative label: Device Driver

Harmonic Mean
type: Class
subclass of: Central Tendency
type: NamedIndividual
d3fend-id: D3A-HM
definition: The reciprocal of the arithmetic mean of the reciprocals of the data values. This measure too is valid only for data that are measured absolutely on a strictly positive scale.
kb-article: ## References Wikipedia. (n.d.). Central tendency. [Link](https://en.wikipedia.org/wiki/Central_tendency)

Heap Segment
type: Class
subclass of: Process Segment
definition: The heap segment (or free store) is a large pool of memory from which dynamic memory requests of a process are allocated and satisfied.

Heterogeneous Asymmetric Feature-based Transfer Learning
type: Class
subclass of: Heterogeneous Transfer Learning
type: NamedIndividual
d3fend-id: D3A-HAFBTL
definition: Asymmetric transformation mapping transforms the source feature space to align with that of the target or the target to that of the source. This, in effect, bridges the feature space gap and reduces the problem into a homogeneous transfer problem when further distribution differences need to be corrected.
kb-article: ## References Wang, Q., Mao, K. Z., Wang, B., & Guan, J. (2017). Big data clustering by hybrid optimization algorithm. Journal of Big Data, 4(1), 25. [Link](https://journalofbigdata.springeropen.com/articles/10.1186/s40537-017-0089-0).

Heterogeneous Feature-based Transfer Learning
type: Class
subclass of: Heterogeneous Transfer Learning
type: NamedIndividual
d3fend-id: D3A-HFBTL
definition: Symmetric transformation takes both the source feature space Xs and target feature space Xt and learns feature transformations as to project each onto a common subspace Xc for adaptation purposes. This derived subspace becomes a domain-invariant feature subspace to associate cross-domain data, and in effect, reduces marginal distribution differences.
kb-article: ## References Wang, Q., Mao, K. Z., Wang, B., & Guan, J. (2017). Big data clustering by hybrid optimization algorithm. Journal of Big Data, 4(1), 25. [Link](https://journalofbigdata.springeropen.com/articles/10.1186/s40537-017-0089-0).

Heterogeneous Transfer Learning
type: Class
subclass of: Transfer Learning
type: NamedIndividual
d3fend-id: D3A-HTL
definition: Heterogeneous transfer learning is characterized by the source and target domains having differing feature spaces, but may also be combined with other issues such as differing data distributions and label spaces.
kb-article: ## References Wang, Q., Mao, K. Z., Wang, B., & Guan, J. (2017). Big data clustering by hybrid optimization algorithm. Journal of Big Data, 4(1), 25. [Link](https://journalofbigdata.springeropen.com/articles/10.1186/s40537-017-0089-0).

Hierarchical Clustering
type: Class
subclass of: Cluster Analysis
type: NamedIndividual
d3fend-id: D3A-HC
definition: Hierarchical clustering (also called hierarchical cluster analysis or HCA) is a method of cluster analysis that seeks to build a hierarchy of clusters.
kb-article: ## References Wikipedia. (2021, August 10). Hierarchical clustering. [Link](https://en.wikipedia.org/wiki/Hierarchical_clustering) html)

Hierarchical Domain Denylisting
type: Class
subclass of: Forward Resolution Domain Denylisting
type: NamedIndividual
kb-reference: Reference-UseDNSPolicyForApplyingFiltersOnDNSQueries
d3fend-id: D3-HDDL
definition: Blocking the resolution of any subdomain of a specified domain name.
kb-article: ## How it works This technique is used to block DNS queries from related domains and subdomains that are unauthorized. Hierarchical domain blacklisting considers the blacklisting of second level domains and additional sub-domains and specific hosts for a given query value. A denylist is maintained that contains DNS names and corresponding subdomains, including wildcards, that should be blocked for a given lookup. ## Considerations * The denylist of domain names will have to be maintained and will need to be kept up to date * Other domains that resolve to the domain of interest for blocking (CNAME, etc). * Denylists should have identified maintenance cycles to ensure lists are not stale.
synonym: Hierarchical Domain Blacklisting

High-dimension Clustering
type: Class
subclass of: Cluster Analysis
type: NamedIndividual
d3fend-id: D3A-HDC
definition: The cluster analysis of data with anywhere from a few dozen to many thousands of dimensions.
kb-article: ## References Wikipedia. (n.d.). Clustering high-dimensional data. [Link](https://en.wikipedia.org/wiki/Clustering_high-dimensional_data)

Higher-order Logic
type: Class
subclass of: Predicate Logic
type: NamedIndividual
d3fend-id: D3A-HOL
definition: Higher-order logic is a form of predicate logic that is distinguished from first-order logic by additional quantifiers and, sometimes, stronger semantics. Higher-order logics with their standard semantics are more expressive, but their model-theoretic properties are less well-behaved than those of first-order logic.
kb-article: ## References 1. Higher-order logic. (2023, May 13). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Higher-order_logic)
synonym: HOL

Histogramming
type: Class
subclass of: Summarizing

Homogenous Transfer Learning
type: Class
subclass of: Transfer Learning
type: NamedIndividual
d3fend-id: D3A-HTL
definition: In homogeneous transfer learning, the feature spaces of the source and target domains is of the same dimension (Ds = Dt) while the data of both domains is represented by the same attributes (Xs = Xt) and labels (Ys = Yt). Thus, homogeneous transfer learning aims to bridge the gap in the data distributions experienced during cross-domain transfer.
kb-article: ## References Khalil, K., Asgher, U., & Ayaz, Y. (2022). Novel fNIRS study on homogeneous symmetric feature-based transfer learning for brain-computer interface. Scientific Reports, 12, 3198. [Link](https://www.nature.com/articles/s41598-022-06805-4).

Homoglyph Denylisting
type: Class
subclass of: Forward Resolution Domain Denylisting
type: NamedIndividual
kb-reference: Reference-DetectionOfMaliciousIDNHomoglyphDomains
d3fend-id: D3-HDL
definition: Blocking DNS queries that are deceptively similar to legitimate domain names.
kb-article: ## How it works Homoglyph domain blacklisting considers the domain and subdomain structure of a lookup and compares the named components to blacklisted named components. The blacklisted named components are typically crafted modifications of known good domains, e.g., gooogle.com versus google.com. The blacklisted domains typically resemble trusted domains, but have been altered slightly to deceive users. The blacklisted named components also include consideration for fonts or Unicode characters that can make certain characters appear very similar (zero vs capital O and the letter l vs the number one). The blacklisted domains under certain fonts will appear to be a trusted domain. ## Considerations * Maintaining the currency of the list can be a challenge especially with newly registered domain entries. * Blacklists should have identified maintenance cycles to ensure lists are not stale.
synonym: Homoglyph Blacklisting

Homoglyph Detection
type: Class
subclass of: Identifier Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Email
subclass of: Restriction
  on property: analyzes
  some values from: URL
type: NamedIndividual
analyzes: Email
analyzes: URL
kb-reference: Reference-Computer-implementedMethodsAndSystemsForIdentifyingVisuallySimilarTextCharacterStrings GreathornInc
kb-reference: Reference-SystemAndMethodForDetectingHomoglyphAttacksWithASiameseConvolutionalNeuralNetwork EndgameInc
d3fend-id: D3-HD
definition: Comparing strings using a variety of techniques to determine if a deceptive or malicious string is being presented to a user.
kb-article: ## How it works A homoglyph, in this context, is a deceptive string or word which looks like a trusted word, but is composed of different characters, for example: goooogle.com versus google.com. This is commonly found in phishing and typo squatting attacks where a human exploiting through a social engineering campaign. ## Considerations * In very large environments processing DNS queries can be computationally expensive due to the amount of traffic that is generated * Legitimate companies and products use non-dictionary words in their names that could result in many false positives

Host
type: Class
subclass of: Computer Network Node
subclass of: Restriction
  on property: contains
  some values from: Application
type: NamedIndividual
contains: Application
definition: A host is a computer or other device, typically connected to a computer network. A network host may offer information resources, services, and applications to users or other nodes on the network. A network host is a network node that is assigned a network layer host address. Network hosts that participate in applications that use the client-server model of computing, are classified as server or client systems. Network hosts may also function as nodes in peer-to-peer applications, in which all nodes share and consume resources in an equipotent manner.
alternative label: Network Host

Host-based Firewall
type: Class
subclass of: System Software
type: NamedIndividual
definition: A software firewall which controls network inbound and outbound network traffic to the host computer.

Host Configuration Sensor
type: Class
subclass of: Endpoint Sensor
subclass of: Restriction
  on property: monitors
  some values from: Application Configuration
subclass of: Restriction
  on property: monitors
  some values from: Operating System Configuration
type: NamedIndividual
monitors: Application Configuration
monitors: Operating System Configuration
definition: Collects the configuration data on an endpoint.

Host Group
type: Class
subclass of: Access Control Group
subclass of: Restriction
  on property: contains
  some values from: Host
type: NamedIndividual
contains: Host
definition: A collection of Hosts used to allow operations such as access control to be applied to the entire group.

Host Reboot
type: Class
subclass of: Host Shutdown
subclass of: Restriction
  on property: terminates
  some values from: Process
type: NamedIndividual
kb-reference: Reference-NearMemoryInMemoryDetectionofFilelessMalware
terminates: Process
d3fend-id: D3-HR
definition: Initiating a host's reboot sequence to terminate all running processes.
kb-article: ## How It Works Host reboot can either be initiated in the physical presence of the device using the power functions or remotely using the provided user interface or an installed EDR agent (with the available function). This process may allow for the removal of specific types of malware, such as fileless malware, and can also prevent further damage, for example, if the system is part of a botnet. ## Considerations - If the attacker has achieved persistence techniques, this technique may not be effective - Compromised systems may not respond to remote commands to shutdown or reboot, requiring physical intervention. - Shutting down a system will usually result in the memory losing its state which can be useful in forensic activities so this should be considered when deciding to shutdown. - Shutting down or rebooting systems may disrupt access to computer resources for legitimate users.

Host Shutdown
type: Class
subclass of: Process Eviction
subclass of: Restriction
  on property: terminates
  some values from: Process
type: NamedIndividual
type: Process Termination
kb-reference: Reference-NearMemoryInMemoryDetectionofFilelessMalware
terminates: Process
d3fend-id: D3-HS
definition: Initiating a host's shutdown sequence to terminate all running processes.
kb-article: ## How It Works Host shutdown can either be initiated in the physical presence of the device using the power functions or remotely using the provided user interface or an installed EDR agent (with the available function). This process may allow for the removal of specific types of malware, such as fileless malware, and can also prevent further damage, for example, if the system is part of a botnet. ## Considerations - If the attacker has achieved persistence techniques, this technique may not be effective - Compromised systems may not respond to remote commands to shutdown or reboot, requiring physical intervention. - Shutting down a system will usually result in the memory losing its state which can be useful in forensic activities so this should be considered when deciding to shutdown. - Shutting down systems may disrupt access to computer resources for legitimate users.

Hostname
type: Class
subclass of: Identifier
subclass of: Restriction
  on property: identifies
  some values from: Host
type: NamedIndividual
type: Domain Name
identifies: Host
definition: In computer networking, a hostname (archaically nodename) is a label that is assigned to a device connected to a computer network and that is used to identify the device in various forms of electronic communication, such as the World Wide Web. Hostnames may be simple names consisting of a single word or phrase, or they may be structured.
alternative label: Nodename

Human Input Device Firmware
type: Class
subclass of: Peripheral Firmware
definition: Firmware that is installed on an HCI device such as a mouse or keyboard.

Hybrid-based Transfer Learning
type: Class
subclass of: Homogenous Transfer Learning
type: NamedIndividual
d3fend-id: D3A-HBTL
definition: This method creates an asymmetric mapping from the target to the source and takes into account bias issues of cross-domain correspondences.
kb-article: ## References Day, O., & Khoshgoftaar, T.M. (2017). A survey on heterogeneous transfer learning. Journal of Big Data, 4(1), 29. [Link](https://doi.org/10.1186/s40537-017-0089-0).

Hypothesis Testing
type: Class
subclass of: Inferential Statistics
type: NamedIndividual
d3fend-id: D3A-HT
definition: A statistical hypothesis test is a method of statistical inference used to decide whether the data at hand sufficiently support a particular hypothesis. Hypothesis testing allows us to make probabilistic statements about population parameters.
kb-article: ## References Wikipedia. (n.d.). Statistical hypothesis testing. [Link](https://en.wikipedia.org/wiki/Statistical_hypothesis_testing)

ID3
type: Class
subclass of: Decision Tree
type: NamedIndividual
d3fend-id: D3A-ID3
definition: ID3 stands for Iterative Dichotomiser 3 and is named such because the algorithm iteratively (repeatedly) dichotomizes(divides) features into two or more groups at each step.
kb-article: ## Addtional Consiterations ID3 is the basis of C4.5, and is best used in natural language processing. ## References Decision Trees for Classification: ID3 Algorithm Explained. Towards Data Science. [Link](https://towardsdatascience.com/decision-trees-for-classification-id3-algorithm-explained-89df76e72df1).

I/O Module
type: Class
subclass of: Hardware Device
definition: An I/O Module is a hardware device that translates signals between external sensors or actuators and control systems. It typically handles analog-to-digital (and vice versa) conversion, serving as the data interface that allows physical processes to be monitored and controlled by digital controllers.

IO Port Restriction
type: Class
subclass of: Access Mediation
subclass of: Restriction
  on property: filters
  some values from: Input Device
subclass of: Restriction
  on property: filters
  some values from: Removable Media Device
type: NamedIndividual
filters: Input Device
filters: Removable Media Device
kb-reference: Reference-ComputerMotherboardHavingPeripheralSecurityFunctions
kb-reference: Reference-MethodAndSystemForControllingCommunicationPorts
kb-reference: Reference-USBFilterForHubMaliciousCodePreventionSystem
d3fend-id: D3-IOPR
definition: Limiting access to computer input/output (IO) ports to restrict unauthorized devices.
kb-article: ## How It works Software-based restriction uses agent software installed on a computer system. The agent software monitors all IO port system traffic. The agent software is configurable to limit the use of certain devices connected to IO ports. The restriction software can also be configured to limit the access to files and applications on external storage devices connected to IO ports. Hardware-based restriction can also be employed to limit access to IO ports. For example, a hardware USB filter device that is placed between the host system and the external devices can filter IO port connections based on configurable rules. When new devices are connected to the USB filter the type of device is determined. Using an allow list a connection determination is made for the device. Some implementations detect when a device is connected in order to authorize the connection against a list of approved devices, in some cases by device type. For example, if the device is determined to be a storage device, then the contained files and executables are examined to more accurately identify the device type. Types of restrictions that may be applied: - Device connection - Device command filtering - Device file system read or write restrictions ## Considerations * Agent software will need to be installed on host systems * Configurations for allow/deny for devices and files will need to be maintained

IP Address
type: Class
subclass of: Identifier
subclass of: Restriction
  on property: identifies
  some values from: Network Node
type: NamedIndividual
identifies: Network Node
definition: An Internet Protocol address (IP address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication.An IP address serves two main functions: host or network interface identification and location addressing. Internet Protocol version 4 (IPv4) defines an IP address as a 32-bit number. However, because of the growth of the Internet and the depletion of available IPv4 addresses, a new version of IP (IPv6), using 128 bits for the IP address, was standardized in 1998. IPv6 deployment has been ongoing since the mid-2000s.

IPC Network Traffic
type: Class
subclass of: Network Traffic
definition: IPC network traffic is network traffic related to inter-process communication (IPC) between network nodes..This includes only network traffic conforming to a standard IPC protocol; not custom protocols.

IPC Traffic Analysis
type: Class
subclass of: Network Traffic Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Intranet IPC Network Traffic
type: NamedIndividual
analyzes: Intranet IPC Network Traffic
kb-reference: Reference-SMBCopyAndExecution MITRE
kb-reference: Reference-SMBEventsMonitoring MITRE
kb-reference: Reference-SMBSessionSetups MITRE
kb-reference: Reference-SMBWriteRequest-NamedPipes MITRE
kb-reference: Reference-SMBWriteRequest MITRE
kb-reference: Reference-SecuritySystemWithMethodologyForInterprocessCommunicationControl CheckPointSoftwareTechInc
kb-reference: Reference-CAR-2015-04-001:RemotelyScheduledTasksViaAT MITRE
d3fend-id: D3-IPCTA
definition: Analyzing standard inter process communication (IPC) protocols to detect deviations from normal protocol activity.
kb-article: ## How it works Inter process communication enables applications or threads to share data. This can involve one or more computers. Monitoring IPC in your environment can reveal abnormal or malicious activity. IPC can occur within a single computer or between multiple computers remotely through network protocols. Thus there are multiple ways to collect and monitor these exchanges between processes. A network protocol analyzer may monitor and parse SMB network traffic to record system activity. A host based monitoring agent may monitor IPC activity contained within a single host to look for deviations from standard usages. ### Examples * SMB * Zeromq * Java RMI API ## Considerations * IPC can generate substantial amounts of data, and it may not be feasible to collect all of it. * IPC may occur over loopback interfaces or direct memory access granted by the operating system.
synonym: IPC Analysis

IP Phone
type: Class
subclass of: Personal Computer
definition: A VoIP phone or IP phone uses voice over IP technologies for placing and transmitting telephone calls over an IP network, such as the Internet, instead of the traditional public switched telephone network (PSTN). Digital IP-based telephone service uses control protocols such as the Session Initiation Protocol (SIP), Skinny Client Control Protocol (SCCP) or various other proprietary protocols.
alternative label: VoIP Phone

IP Reputation Analysis
type: Class
subclass of: Identifier Reputation Analysis
subclass of: Restriction
  on property: analyzes
  some values from: IP Address
type: NamedIndividual
analyzes: IP Address
kb-reference: Reference-Database for receiving storing and compiling information about email messages
kb-reference: Reference-Finding phishing sites
d3fend-id: D3-IPRA
definition: Analyzing the reputation of an IP address.

Identifier
type: Class
subclass of: Digital Information
subclass of: Restriction
  on property: identifies
  some values from: Artifact
type: NamedIndividual
identifies: Artifact
definition: An identifier is a name that identifies (that is, labels the identity of) either a unique object or a unique class of objects, where the "object" or class may be an idea, physical [countable] object (or class thereof), or physical [noncountable] substance (or class thereof). The abbreviation ID often refers to identity, identification (the process of identifying), or an identifier (that is, an instance of identification). An identifier may be a word, number, letter, symbol, or any combination of those.
alternative label: ID

Identifier Activity Analysis
type: Class
subclass of: Identifier Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Identifier
type: NamedIndividual
analyzes: Identifier
kb-reference: Reference-ThePyramidOfPain-DavidBianco
d3fend-id: D3-IAA
definition: Taking known malicious identifiers and determining if they are present in a system.
kb-article: ## How it works Identifier activity analysis is the process of taking identifiers--typically known malicious identifiers--and determining the artifacts that have interacted with those identifiers. There are many open and closed source repositories of identifiers that represent indicators of compromise. For example, VirusTotal contains hash signatures of malware and IP Addresses used by threat actors. Defenders can search for these indicators of compromise their own systems to gain context on activity around an identifier. ## Considerations Indicator activity analysis is a good way to gain high precision analysis, but adversaries can modify their own signatures such as hashes quickly to evade detection. This is related to David Bianco’s Pyramid of Pain - Indicators on the lower level (hash values, IP addresses domain names) are easy for adversaries to change. Identifier activity data of interest for analysis with the identifier might include, but is not limited to: * network traffic activity where the identifier was used to identify communicating entities or referred to in the communication * process activity referencing the identifier, especially for resource access * file activity referencing the identifier * registry settings referencing the identifier

Identifier Analysis
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Detect
type: NamedIndividual
enables: Detect
d3fend-id: D3-ID
definition: Analyzing identifier artifacts such as IP address, domain names, or URL(I)s.

Identifier Reputation Analysis
type: Class
subclass of: Identifier Analysis
type: NamedIndividual
kb-reference: Reference-Finding phishing sites
d3fend-id: D3-IRA
definition: Analyzing the reputation of an identifier.

Image-to-Image Translation GAN
type: Class
subclass of: Generative Adversarial Network
type: NamedIndividual
d3fend-id: D3A-ITITG
definition: Image-to-image translation is the task of transferring styles and characteristics from one image domain to another.
kb-article: ## References MathWorks. (n.d.). Get Started with GANs for Image-to-Image Translation. [Link](https://www.mathworks.com/help/images/get-started-with-gans-for-image-to-image-translation.html)

Image Code Segment
type: Class
subclass of: Image Segment
subclass of: Restriction
  on property: contains
  some values from: Subroutine
type: NamedIndividual
contains: Subroutine
definition: An image code segment, also known as a text segment or simply as text, is a portion of an object file that contains executable instructions. The term "segment" comes from the memory segment, which is a historical approach to memory management that has been succeeded by paging. When a program is stored in an object file, the code segment is a part of this file; when the loader places a program into memory so that it may be executed, various memory regions are allocated (in particular, as pages), corresponding to both the segments in the object files and to segments only needed at run time. For example, the code segment of an object file is loaded into a corresponding code segment in memory.

Image Data Segment
type: Class
subclass of: Image Segment
type: NamedIndividual
definition: An image data segment (often denoted .data) is a portion of an object file that contains initialized static variables, that is, global variables and static local variables. The size of this segment is determined by the size of the values in the program's source code, and does not change at run time. This segmenting of the memory space into discrete blocks with specific tasks carried over into the programming languages of the day and the concept is still widely in use within modern programming languages.

Image Scanner Input Device
type: Class
subclass of: Video Input Device
definition: An image scanner -- often abbreviated to just scanner, is a device that optically scans images, printed text, handwriting or an object and converts it to a digital image. Commonly used in offices are variations of the desktop flatbed scanner where the document is placed on a glass window for scanning. Hand-held scanners, where the device is moved by hand, have evolved from text scanning "wands" to 3D scanners used for industrial design, reverse engineering, test and measurement, orthotics, gaming and other applications. Mechanically driven scanners that move the document are typically used for large-format documents, where a flatbed design would be impractical.
alternative label: Scanner

Image Segment
type: Class
subclass of: Binary Segment
subclass of: File Section
definition: Image segments are distinct partitions of an object file. Both data and code segments are examples of image segments.

Image Synthesis GAN
type: Class
subclass of: Generative Adversarial Network
type: NamedIndividual
d3fend-id: D3A-ISG
definition: Image synthesis thorugh the application of Generative Adversarial Networks.
kb-article: ## References Zhang, Q., Wang, H., Lu, H., Won, D., & Yoon, S. W. (2018). Medical Image Synthesis with Generative Adversarial Networks for Tissue Recognition. 2018 IEEE International Conference on Healthcare Informatics (ICHI), 199-207. doi: 10.1109/ICHI.2018.00030. [Link](https://ieeexplore.ieee.org/document/8419363)

Impact Technique
type: Class
subclass of: ATTACK Enterprise Technique
subclass of: Offensive Technique
subclass of: Restriction
  on property: enables
  some values from: Impact
type: NamedIndividual
enables: Impact

Impersonate User
type: Class
subclass of: System Call
subclass of: Restriction
  on property: forges
  some values from: User Account
type: NamedIndividual
type: System Call
forges: User Account

Import Library Function
type: Class
subclass of: Subroutine
subclass of: Restriction
  on property: loads
  some values from: Shared Library File
type: NamedIndividual
loads: Shared Library File
definition: Loads an external software library to enable the invocations of its methods.

In-memory Password Store
type: Class
subclass of: Password Store
type: NamedIndividual
definition: A password store held in memory.

Inbound Internet DNS Response Traffic
type: Class
subclass of: Inbound Internet Network Traffic
type: NamedIndividual
definition: Inbound internet DNS response traffic is DNS response traffic from a host outside a given network initiated on an incoming connection to a host inside that network.

Inbound Internet Mail Traffic
type: Class
subclass of: Inbound Internet Network Traffic
subclass of: Inbound Network Traffic
subclass of: Mail Network Traffic
type: NamedIndividual
definition: Inbound internet mail traffic is network traffic that is: (a) coming from a host outside a given network via an incoming connection to a host inside that same network, and (b) using a standard protocol for email.

Inbound Internet Network Traffic
type: Class
subclass of: Inbound Network Traffic
subclass of: Internet Network Traffic
subclass of: Restriction
  on property: produces
  some values from: Network Traffic
type: NamedIndividual
produces: Network Traffic
definition: Inbound internet traffic is network traffic from a host outside a given network initiated on an incoming connection to a host inside that network.

Inbound Network Traffic
type: Class
subclass of: Network Traffic
type: NamedIndividual
definition: Inbound traffic is network traffic originating from another host (client), to the host of interest (server).

Inbound Session Volume Analysis
type: Class
subclass of: Network Traffic Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Inbound Internet Network Traffic
type: NamedIndividual
analyzes: Inbound Internet Network Traffic
kb-reference: Reference-DetectingDDoSAttackUsingSnort
kb-reference: Reference-IdentifyingADenial-of-serviceAttackInACloud-basedProxyService-CloudfareInc.
kb-reference: Reference-MethodAndSystemForUDPFloodAttackDetection-RioreyLLC
kb-reference: Reference-ProtectingAgainstDistributedDenialOfServiceAttacks-CiscoTechnologyInc.
kb-reference: Reference-ProtectingAgainstDistributedNetworkFloodAttacks-JuniperNetworksInc.
d3fend-id: D3-ISVA
definition: Analyzing inbound network session or connection attempt volume.
kb-article: ## How it works Network appliances are configured to alert on certain packets that typically are involved in DoS attacks. Typical packets include ICMP packets and SYN requests that are commonly used to flood networks. A sampling period is used to define a time window in which collected counts of the identified packets can be measured. If the collected number of packets exceeds a predefined limit then an alert is generated. ## Considerations Scalability as volume of attacks increase; single servers may not have the memory and storage resources to handle high volumes of network traffic.

Inbound Traffic Filtering
type: Class
subclass of: Network Traffic Filtering
subclass of: Restriction
  on property: filters
  some values from: Inbound Network Traffic
type: NamedIndividual
filters: Inbound Network Traffic
kb-reference: Reference-ActiveFirewallSystemAndMethodology McAfeeLLC
kb-reference: Reference-AutomaticallyGeneratingRulesForConnectionSecurity Microsoft
kb-reference: Reference-FWTK-FirewallToolkit
kb-reference: Reference-FirewallForInterentAccess SecureComputingLLC
kb-reference: Reference-FirewallForProcessingAConnectionlessNetworkPacket NationalSecurityAgency
kb-reference: Reference-FirewallForProcessingConnection-orientedAndConnectionlessDatagramsOverAConnection-orientedNetwork NationalSecurityAgency
kb-reference: Reference-FirewallsThatFilterBasedUponProtocolCommands IntelCorp
kb-reference: Reference-MethodForControllingComputerNetworkSecurity CheckpointSoftwareTechnologiesLtd
kb-reference: Reference-NetworkFirewallWithProxy SecureComputingLLC
d3fend-id: D3-ITF
definition: Restricting network traffic originating from untrusted networks destined towards a private host or enclave.
kb-article: ## How it works Inbound Traffic, in this context, is network traffic originating from an untrusted network towards a private host or enclave. For example: * An untrusted network host connecting to a internal commercial portal, shopping.example.com * An external mail server connecting to an internal mail server, mail.example.com Filtering policies are developed by administrators to meet business requirements and limit connectivity. These policies are implemented on edge devices such as firewalls, routers, and intrusion prevention systems. Examples of filters: * Blocking incoming traffic from spoofed internally facing IP addresses * Blocking specific ports and services from establishing connections * Limiting specific IP ranges from connecting to the network * Dynamic inbound filtering (Hole punching, STUN, NAT-T) ## Considerations * Business requirements typically drive the development of filtering rulesets * Protocols using non-standard ports may circumvent filtering technology, which does not detect application protocol based on traffic content ## Implementations * OpenWRT (Embedded) * Netfilter (Linux) * Windows Firewall * pf(BSD)

Indirect Branch Call Analysis
type: Class
subclass of: Process Analysis
type: NamedIndividual
kb-reference: Reference-IndirectBranchingCalls
d3fend-id: D3-IBCA
definition: Analyzing vendor specific branch call recording in order to detect ROP style attacks.
kb-article: ## How it works This technique is used to detect an attacker attempting to exploit and execute code on a target system's call stack using return-oriented programming (ROP). Modern processors that have the ability to maintain a list of the branching calls, e.g., Intel's Last Branch Recording (LBR), can be used to track and analyze indirect branching calls that are indicative of malicious activity. In order to reduce the number of indirect branch calls to analyze to a manageable set it is assumed that malicious ROP activity will involve the use of system calls. The technique observes indirect branch calls that are part of paths that lead to system calls, all others are ignored. Branching calls chained together is often referred to as gadgets and gadgets are often used in ROP attacks. Indirect branch calls that involve a transfer from user-space to kernel-space are of interest for this technique. Identification of potential ROP exploit execution includes: - Inspecting the LBR when a system function call is made - The LBR is configured to return only instruction of interest (ret, indirect jmp, indirect calls) - Behavior is analyzed for - Ret instructions that appear to target areas not preceded by the call sites - Sequences of small code fragments that appear to be chained through the indirect branching calls (gadgets) - Of interest are returns that appear to not render control back after calls - Typical ret-call are paired - gadgets will appear to have ret followed by instruction of next instruction of the following gadget ## Considerations * May be operating system dependent since specific system calls are used to scope branching behavoir * Processors need to support access to a Last Branch Recording list feature * The size of the LBR stack can limit the expected size of the analyzed execution stack * If processor does not support LBR then overhead costs for the analysis can be significant

Inferential Statistics
type: Class
subclass of: Statistical Method
type: NamedIndividual
d3fend-id: D3A-IS
definition: Statistical inference is the process of using data analysis to infer properties of an underlying distribution of probability.
kb-article: ## References Wikipedia. (n.d.). Statistical inference. [Link](https://en.wikipedia.org/wiki/Statistical_inference)

Init Script
type: Class
subclass of: Executable Script
definition: An init script (or initialization script) is an executable script that initializes the an application, a process, or a service's state. Examples include scripts run at boot by Unix or Windows, or those run to initialize a shell.
alternative label: Initialization Script

Initial Access Technique
type: Class
subclass of: ATTACK Enterprise Technique
subclass of: Offensive Technique
subclass of: Restriction
  on property: enables
  some values from: Initial Access
type: NamedIndividual
enables: Initial Access

Input Device
type: Class
subclass of: Hardware Device
subclass of: Local Resource
type: NamedIndividual
definition: In computing, an input device is a piece of equipment used to provide data and control signals to an information processing system such as a computer or information appliance. Examples of input devices include keyboards, mouse, scanners, digital cameras, joysticks, and microphones. Input devices can be categorized based on:

Input Device Analysis
type: Class
subclass of: Operating System Monitoring
subclass of: Restriction
  on property: analyzes
  some values from: Input Device
type: NamedIndividual
analyzes: Input Device
kb-reference: Reference-www.biometric-solutions.com keystroke-dynamics
kb-reference: Reference-ContinuousAuthenticationByAnalysisOfKeyboardTypingCharacteristics BradfordUniv.,UK
d3fend-id: D3-IDA
definition: Operating system level mechanisms to prevent abusive input device exploitation.
kb-article: ## How it works Input Device Hardening techniques filter certain commands, or disable related operating system functionality. ### Analytics All of these values can be analyzed and compared to a baseline: * Amount of input * Duration of a single input * Durations between inputs * Value of input Context can also include: * User which is logged in, to include attributes such as physical location of the user * Date and time * System which is processing the input * Source device of input, to include its properties (eg. manufacturer), configuration (eg. keyboard layout) and behavioral attributes of this device (eg. first use) * Source system of input (local or remote system) * Other hardware devices attached to the system ### Actions Actions can include: * Disabling the source device * Sending an alert * Locking the current session (eg. system screen lock, or returning to an authentication screen in a web app) and requiring one or more methods of authentication to continue * Administratively disabling credentials for the account or the entire account -- the technique *Account Locking* ### Examples A malicious input device sends many keystrokes with approximately the same delay between each. This does not match the normal cadence of input, and the device is disabled. Input to type the session user's name takes abnormally longer for each keystroke. The system is locked to the password prompt screen. A system receives key press events from two different devices -- one device sends keystrokes after the other has been idle for a long time. A system receives physical input in a user session, while that user has sent input from a device located out of the country in the past hour. Network traffic is suddenly routed through a new external device, and nearly the same volume of network traffic is subsequently sent out the previously existing interface. The new external device is disabled, and an alert is raised to investigate the network configuration for a potential compromise. ##…

Input Device Event
type: Class
subclass of: Hardware Device Event
subclass of: Restriction
  on property: has-participant
  some values from: Input Device
definition: An event involving human-machine interface devices, such as keyboards, mice, or touchscreens.

Input Function
type: Class
subclass of: Subroutine
definition: Generic function that receives input from an untrusted source.

Instance-based Transfer Learning
type: Class
subclass of: Homogenous Transfer Learning
type: NamedIndividual
d3fend-id: D3A-IBTL
definition: Instance-based transfer learning methods try to reweight the samples in the source domain in an attempt to correct for marginal distribution differences. These reweighted instances are then directly used in the target domain for training.
kb-article: ## References Georgian Impact Blog. (n.d.). Transfer Learning Part 1. [Link](https://medium.com/georgian-impact-blog/transfer-learning-part-1-ed0c174ad6e7#:~:text=Homogeneous%20Transfer%20Learning-,1.,the%20target%20domain%20for%20training).

Instant Messaging Client
type: Class
subclass of: Collaborative Software
definition: Client software used to engage in Instant Messaging, a type of online chat that offers real-time text transmission over the Internet. A LAN messenger operates in a similar way over a local area network. Short messages are typically transmitted between two parties, when each user chooses to complete a thought and select "send". Some IM applications can use push technology to provide real-time text, which transmits messages character by character, as they are composed. More advanced instant messaging can add file transfer, clickable hyperlinks, Voice over IP, or video chat.

Integer Range Validation
type: Class
subclass of: Source Code Hardening
subclass of: Restriction
  on property: hardens
  some values from: Mathematical Function
type: NamedIndividual
hardens: Mathematical Function
kb-reference: Reference-IntegerRangeValidation SEI
d3fend-id: D3-IRV
definition: Ensuring that an integer is within a valid range.
kb-article: ## How it Works Integer Range Validation can be done by programmatically checking the value of an integer before or after an operation to determine if the resulting value will be valid. Checking the value of an integer to ensure it is in a valid range helps prevent integer overflow, wraparound, and logical errors. ## Considerations * A valid range can be defined by language, data-type, or logical constraints. * Take extra care when doing operations on integers that will result in a value close to the bounds of a valid range. * Note: This resource should not be considered a definitive or exhaustive coding guideline.

Integrated Honeynet
type: Class
subclass of: Decoy Environment
subclass of: Restriction
  on property: spoofs
  some values from: Intranet Network
type: NamedIndividual
kb-reference: Reference-SynchronizingAHoneyNetworkConfigurationToReflectATargetNetworkEnvironment PaloAltoNetworksInc
spoofs: Intranet Network
d3fend-id: D3-IHN
definition: The practice of setting decoys in a production environment to entice interaction from attackers.
kb-article: ## How it works Integrated honeynets use full production environments connected to the enterprise network, that utilize computing resources or software that attract attackers, and allow full interaction and access that provides a complete view of an attack. ## Considerations An attacker with control of a system on an Integrated Honeynet could: * try to attack other connected hosts on the network, its IP range of internal hosts not properly configured to react to connections from machines on the integrated honeynet, or position behind the firewall. * exploit its position by eavesdropping on network traffic If an attacker manages to stop the processes used to log an attack without setting off any alarms. [1] 1. Honeypots for Windows, Roger Grimes, 2005

Integration Test Execution Tool
type: Class
subclass of: Test Execution Tool
definition: An integration test execution tool automatically performs integration testing. Integration testing (sometimes called integration and testing, abbreviated I&T) is the phase in software testing in which individual software modules are combined and tested as a group.

Internet Article Reference
type: Class
subclass of: Technique Reference
pref-label: Internet Article
alternative label: Internet Blog Reference

Internet DNS Lookup
type: Class
subclass of: DNS Lookup
definition: An internet Domain Name System (DNS) lookup is a DNS lookup made from a host on a network that is resolved after querying a DNS name server hosted on a different network.

Internet File Transfer Traffic
type: Class
subclass of: File Transfer Network Traffic
subclass of: Internet Network Traffic
definition: Internet file transfer network traffic is network traffic related to file transfers between network nodes that crosses a boundary between networks. This includes only network traffic conforming to standard file transfer protocols, not custom transfer protocols.

Internet Network
type: Class
subclass of: Network
definition: A network of multiple, connected networks. Internetworking is the practice of connecting a computer network with other networks through the use of gateways that provide a common method of routing information packets between the networks. The resulting system of interconnected networks are called an internetwork, or simply an internet. Internetworking is a combination of the words inter ("between") and networking; not internet-working or international-network.
alternative label: Interconnected Network
alternative label: Internet
alternative label: Internetwork

Internet Network Traffic
type: Class
subclass of: Network Traffic
type: NamedIndividual
definition: Internet network traffic is network traffic that crosses a boundary between networks. [This is the general sense of inter-networking; It may or may not cross to or from the Internet]

Internet Persona
type: Class
subclass of: Digital Information Bearer
definition: A social identity that an Internet user establishes in online communities and websites. It may also be an actively constructed presentation of oneself.
alternative label: Online Identity
alternative label: Online Persona
alternative label: Online Personality

Interprocess Communication
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: In computer science, inter-process communication or inter-process communication (IPC) refers specifically to the mechanisms an operating system provides to allow processes it manages to share data. Typically, applications can use IPC categorized as clients and servers, where the client requests data and the server responds to client requests. Many applications are both clients and servers, as commonly seen in distributed computing. Methods for achieving IPC are divided into categories which vary based on software requirements, such as performance and modularity requirements, and system circumstances, such as network bandwidth and latency.

Interquartile Range
type: Class
subclass of: Variability
type: NamedIndividual
d3fend-id: D3A-IR
definition: The interquartile range (IQR) is a measure of statistical dispersion, which is the spread of the data and is defined as the difference between the 75th and 25th percentiles of the data.
kb-article: ## References Wikipedia. (n.d.). Interquartile range. [Link](https://en.wikipedia.org/wiki/Interquartile_range)
synonym: IQR

Interval Estimation
type: Class
subclass of: Estimation
type: NamedIndividual
d3fend-id: D3A-IE
definition: Interval estimation is the use of sample data to estimate an interval of possible values of a parameter of interest.
kb-article: ## References Wikipedia. (n.d.). Interval estimation. [Link](https://en.wikipedia.org/wiki/Interval_estimation)

Intranet Administrative Network Traffic
type: Class
subclass of: Administrative Network Traffic
subclass of: Intranet Network Traffic
type: NamedIndividual
definition: Intranet administrative network traffic is administrative network traffic that does not cross a given network's boundaries and uses a standard administrative protocol.

Intranet DNS Lookup
type: Class
subclass of: DNS Lookup
definition: An Intranet Domain Name System (DNS) lookup is a DNS lookup made from a host on a network that is resolved after querying a DNS name server hosted on a that same network.

Intranet File Transfer Traffic
type: Class
subclass of: File Transfer Network Traffic
subclass of: Intranet Network Traffic
type: NamedIndividual
definition: Intranet file transfer traffic is file transfer traffic that does not cross a given network's boundaries and uses a standard file transfer protocol.

Intranet IPC Network Traffic
type: Class
subclass of: IPC Network Traffic
subclass of: Intranet Network Traffic
subclass of: Restriction
  on property: may-contain
  some values from: File
type: NamedIndividual
may-contain: File
definition: Intranet IPC network traffic is network traffic that does not cross a given network's boundaries and uses a standard inter-process communication (IPC) networking protocol.

Intranet Multicast Network Traffic
type: Class
subclass of: Intranet Network Traffic
type: NamedIndividual
definition: Intranet IPC network traffic is multicast network traffic that does not cross a given network's boundaries.

Intranet Network
type: Class
subclass of: Network
type: NamedIndividual
definition: An intranet is a private network accessible only to an organization's staff or delegates. Generally a wide range of information and services from the organization's internal IT systems are available that would not be available to the public from the Internet. A company-wide intranet can constitute an important focal point of internal communication and collaboration, and provide a single starting point to access internal and external resources. In its simplest form an intranet is established with the technologies for local area networks (LANs) and wide area networks (WANs).

Intranet Network Traffic
type: Class
subclass of: Network Traffic
type: NamedIndividual
definition: Intranet network traffic is network traffic traversing that does not traverse a given network's boundaries.

Intranet RPC Network Traffic
type: Class
subclass of: Intranet Network Traffic
subclass of: RPC Network Traffic
definition: Intranet RPC network traffic is network traffic that does not cross a given network's boundaries and uses a standard remote procedure call (e.g., RFC 1050) protocol.

Intranet Web Network Traffic
type: Class
subclass of: Intranet Network Traffic
subclass of: Web Network Traffic
subclass of: Restriction
  on property: may-contain
  some values from: File
type: NamedIndividual
may-contain: File
definition: Intranet web network traffic is network traffic that does not cross a given network's boundaries and uses a standard web protocol.

Intrinsically Semi-supervised Learning
type: Class
subclass of: Semi-Supervised Learning
type: NamedIndividual
d3fend-id: D3A-ISSL
definition: These methods directly optimize an objective function with components for labeled and unlabeled samples and do not rely on any intermediate steps or supervised base learners. Basically, these methods are extension of existing supervised methods to include the effect of unlabeled data samples in the objective function.
kb-article: ## References Beginner's Guide to Semi-Supervised Learning. Jashish Blog. [Link](http://jashish.com.np/blog/posts/beginners-guide-to-semi-supervised-learning/).

Intrusion Detection System
type: Class
subclass of: Digital Information Bearer
definition: An intrusion detection system (IDS) is a device or software application that monitors a network or systems for malicious activity or policy violations. Any intrusion activity or violation is typically reported either to an administrator or collected centrally using a security information and event management (SIEM) system. A SIEM system combines outputs from multiple sources and uses alarm filtering techniques to distinguish malicious activity from false alarms.
alternative label: IDS

Intrusion Prevention System
type: Class
subclass of: Intrusion Detection System
definition: Intrusion prevention systems (IPS), also known as intrusion detection and prevention systems (IDPS), are network security appliances that monitor network or system activities for malicious activity. The main functions of intrusion prevention systems are to identify malicious activity, log information about this activity, report it and attempt to block or stop it. Intrusion prevention systems are considered extensions of intrusion detection systems because they both monitor network traffic and/or system activities for malicious activity. The main differences are, unlike intrusion detection systems, intrusion prevention systems are placed in-line and are able to actively prevent or block intrusions that are detected. IPS can take such actions as sending an alarm, dropping detected malicious packets, resetting a connection or blocking traffic from the offending IP address. An IPS also can correct cyclic redundancy check (CRC) errors, defragment packet streams, mitigate TCP sequencing issues, and clean up unwanted transport and network layer options.
alternative label: IDPS
alternative label: IPS
alternative label: Intrusion Detection and Prevention System

Isolate
type: Class
subclass of: Defensive Tactic
type: NamedIndividual
type: Defensive Tactic
definition: The isolate tactic creates logical or physical barriers in a system which reduces opportunities for adversaries to create further accesses.
display-order: 2
display-priority: 0

Isolation Event
type: Class
subclass of: Security Event
type: NamedIndividual
related: Isolate
definition: An event involving actions to create logical or physical barriers that isolate compromised components, preventing adversary movement and reducing attack surfaces.

Java Archive
type: Class
subclass of: Archive File
subclass of: Software Package
definition: A JAR (Java ARchive) is a package file format typically used to aggregate many Java class files and associated metadata and resources (text, images, etc.) into one file for distribution.

JavaScript Blob
type: Class
subclass of: Binary Large Object
type: NamedIndividual
definition: A JavaScript Blob is a Blob that was created by a JavaScript Blob() constructor call or equivalent function.

Job Function Access Pattern Analysis
type: Class
subclass of: User Behavior Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Authorization
type: NamedIndividual
analyzes: Authorization
kb-reference: Reference-AnomalyDetectionUsingAdaptiveBehavioralProfiles SecuronixInc
d3fend-id: D3-JFAPA
definition: Detecting anomalies in user access patterns by comparing user access activity to behavioral profiles that categorize users by role such as job title, function, department.
kb-article: ## How it works Peer group analysis identifies functionally similar groups of actors (users or resources) based on categorizations such as job title, organizational hierarchy, or other attribute that indicates similarity of job function. Current user access activity is then compared to the appropriate peer group behavior profile to identify anomalies. ## Considerations Potential for false positives from anomalies that are not associated with malicious activity.

Job Schedule
type: Class
subclass of: Digital Information
subclass of: Restriction
  on property: contains
  some values from: Scheduled Job
subclass of: Restriction
  on property: modified-by
  some values from: Job Scheduler Software
type: NamedIndividual
contains: Scheduled Job
modified-by: Job Scheduler Software
definition: A job schedule contains specification of tasks to be executed at particular times or time intervals. The schedule is a plan that enacted by a task scheduling process. In Windows, the schedule can be accessed at 'C:\Windows\System32\Tasks' or in the registry. In Linux, the schedule is located at '/etc/crontab'
synonym: Task Schedule

Job Scheduler Software
type: Class
subclass of: System Service Software
subclass of: Restriction
  on property: creates
  some values from: Scheduled Job
subclass of: Restriction
  on property: modifies
  some values from: Job Schedule
subclass of: Restriction
  on property: modifies
  some values from: Scheduled Job
type: NamedIndividual
creates: Scheduled Job
modifies: Job Schedule
modifies: Scheduled Job
definition: A job scheduler software is operating system software that when run executes scheduled tasks (time-scheduling in the sense of wall clock time; not operating system scheduling of processes for multitasking). Processes running such software are task scheduler processes. In Windows, Scheduled Tasks are created and managed by the Task Scheduler. In Unix-like OSes, the `cron` utitility serves a similar role.
synonym: Task Scheduler Software

K-Center Clustering
type: Class
subclass of: Graph-based Clustering
type: NamedIndividual
d3fend-id: D3A-KCC
definition: K-center Clustering is a type of clustering based on an combinatorial optimization methods. It clusters a set of points so as to minimize the maximum intercluster distance.
kb-article: ## How it works An example K-center Clustering problem is to mimimize the number of points in a set that are necessary so that a every other point in the set is within some fixed distance of those points. For instance, given n cities with specified distances, one wants to build k warehouses in different cities and minimize the maximum distance of a city to a warehouse. ## Considerations - **Scalability**: Exact solutions are NP-hard. However, algorithms that have been proven effective and create no more than 2x the optimal set of clusters can run in O(kn) proportional to k*n where k is the minimum number of clusters and n is the number of data points being clustered. ## Key Test Considerations - **Unsupervised Learning**: - **Number of Clusters**: The Gonzalez (Gon) algorithm guarantees creating no more than twice the optimal number of clusters, where the optimal number is the minimum number of clusters to minimize total distance between representative points in the clusters [1]. - **Cluster Analysis**: - **Rand Index and Adjusted Rand Index**: Given ground truth set of class labels for the data, the Rand Index is a measure of the similarity between two data clusterings. The Rand Index is the accuracy of determining if a link belongs within a cluster or not. A form of the Rand Index may be defined that is adjusted for the chance grouping of elements, this is the Adjusted Rand Index [5]. - **Adjusted Mutual Information**: Given ground truth set of class labels for the data, Adjusted Mutual Information corrects the effect of agreement solely due to chance between clusterings, similar to the way the Adjusted Rand Index corrects the Rand Index [6]. - **Connection-based Clustering**: - **Choice of Distance Metric**: The outcome can vary significantly depending on the chosen distance metric (e.g., Euclidean, Manhattan). - **Sensitivity**: Connection-based method can be sensitive to outliers, which might affect the quality of the clusters formed. - **K-center Clustering**:…

K-Fold Cross-Validation
type: Class
subclass of: Resampling Ensemble
type: NamedIndividual
d3fend-id: D3A-KFCV
definition: Cross-validation is a resampling procedure used to evaluate machine learning models on a limited data sample. The procedure has a single parameter called k that refers to the number of groups that a given data sample is to be split into. As such, the procedure is often called k-fold cross-validation. When a specific value for k is chosen, it may be used in place of k in the reference to the model, such as k=10 becoming 10-fold cross-validation
kb-article: ## References K-Fold Cross-Validation. Machine Learning Mastery. [Link](https://machinelearningmastery.com/k-fold-cross-validation/#:~:text=Cross%2Dvalidation%20is%20a%20resampling,k%2Dfold%20cross%2Dvalidation).

K-Nearest Neighbors
type: Class
subclass of: Classification
type: NamedIndividual
d3fend-id: D3A-KNN
definition: The k-nearest neighbors algorithm, also known as KNN or k-NN, is a non-parametric, supervised learning classifier, which uses proximity to make classifications or predictions about the grouping of an individual data point.
kb-article: ## **How it works** The goal of the k-nearest neighbor algorithm is to identify the nearest neighbors of a given query point, so that we can assign a class label to that point. To determine which data points are closest to a given query point, the distance between the query point and the other data points will need to be calculated. The distance measures used can vary depending on the data set or implementation and help inform decision boundaries, which query points into different regions. Then, by defining the k-value (the number of neighbors to be checked to determine the classification of a specific query point), the data can be assigned its class label. For classification problems, a class label is assigned on the basis of a majority vote—i.e. the label that is most frequently represented around a given data point is used (the term “majority vote” is commonly used in literature, however, the technique is more technically considered “plurality voting”). Regression problems use a similar concept as classification problem, but in this case, the average the k nearest neighbors is taken to make a prediction about a classification. The main distinction here is that classification is used for discrete values, whereas regression is used with continuous ones. Unlike other algorithms that explicitly model the problem, such as linear regression, KNN is instance-based. It means that the algorithm doesn't explicitly learn a model. Instead, it memorizes the training instances and uses them as "knowledge" for the prediction phase. It's also worth noting that the KNN algorithm is also part of a family of “lazy learning” models, meaning that it only stores a training dataset versus undergoing a training stage. ## **Considerations** * **Scaling:** Scaling is a problem as KNN is a lazy algorithm and takes up more memory and storage compared to other classification methods. * **Implementation and Hyperparameters:** As KNN only requires a k-value and a distance metric, it is often a…

K-means Clustering
type: Class
subclass of: Centroid-based Clustering
type: NamedIndividual
d3fend-id: D3A-KMC
definition: K-means algorithm identifies k number of centroids, and then allocates every data point to the nearest cluster, while keeping the centroids as small as possible.
kb-article: ## References Towards Data Science. (n.d.). Understanding K-means Clustering in Machine Learning. [Link](https://towardsdatascience.com/understanding-k-means-clustering-in-machine-learning-6a6e67336aa1)

Kendall's Rank Correlation Coefficient
type: Class
subclass of: Rank Correlation
type: NamedIndividual
d3fend-id: D3A-KRCC
definition: Kendall's $\\tau$ between and is given by $(n_c - n_d) / \\sqrt((n_c+n_d+n_x)(n_c+n_d+n_y)$, where is the number of concordant pairs of observations, is the number of discordant pairs, is the number of ties involving only the variable, and is the number of ties involving only the variable." ;
kb-article: ## References 1. Wolfram Research. (2012). KendallTau. Wolfram Language function. [Link](https://reference.wolfram.com/language/ref/KendallTau.html) 1. Kendall's Tau. (2023, May 23). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Kendall_rank_correlation_coefficient]""",
synonym: Kendall's Tau Coefficient

Kerberos Ticket
type: Class
subclass of: Access Token
type: NamedIndividual
definition: An access ticket/token issued by a Kerberos system.

Kerberos Ticket Granting Service Ticket
type: Class
subclass of: Kerberos Ticket
definition: A Kerberos ticket-granting service (TGS) ticket is given in response to requesting a Kerberos TGS request.
alternative label: TGS Ticket

Kerberos Ticket Granting Ticket
type: Class
subclass of: Kerberos Ticket
subclass of: Ticket Granting Ticket
type: NamedIndividual
definition: A ticket granting ticket issued by a Kerberos system; that is, a ticket that grants a user domain admin access.

Kerberos Ticket Granting Ticket Account
type: Class
subclass of: Service Account
subclass of: Restriction
  on property: creates
  some values from: Kerberos Ticket Granting Ticket
type: NamedIndividual
creates: Kerberos Ticket Granting Ticket
definition: KRBTGT is an account used by Key Distribution Center (KDC) service to issue Ticket Granting Tickets (TGTs) as part of the Kerberos authentication protocol.
synonym: krbtgt

Kernel
type: Class
subclass of: System Software
subclass of: Restriction
  on property: contains
  some values from: Kernel Process Table
subclass of: Restriction
  on property: loads
  some values from: Application
subclass of: Restriction
  on property: manages
  some values from: Operating System Process
subclass of: Restriction
  on property: manages
  some values from: User Process
subclass of: Restriction
  on property: may-contain
  some values from: Hardware Driver
subclass of: Restriction
  on property: may-contain
  some values from: Kernel Module
type: NamedIndividual
contains: Kernel Process Table
loads: Application
manages: Operating System Process
manages: User Process
may-contain: Hardware Driver
may-contain: Kernel Module
definition: The kernel is a computer program that constitutes the central core of a computer's operating system. It has complete control over everything that occurs in the system. As such, it is the first program loaded on startup, and then manages the remainder of the startup, as well as input/output requests from software, translating them into data processing instructions for the central processing unit. It is also responsible for managing memory, and for managing and communicating with computing peripherals, like printers, speakers, etc. The kernel is a fundamental part of a modern computer's operating system.

Kernel-based Process Isolation
type: Class
subclass of: Execution Isolation
subclass of: Restriction
  on property: isolates
  some values from: Process
type: NamedIndividual
isolates: Process
kb-reference: Reference-OverviewOfTheSeccompSandbox
d3fend-id: D3-KBPI
definition: Using kernel-level capabilities to isolate processes.
comment: e.g. KVM

Kernel API Sensor
type: Class
subclass of: Endpoint Sensor
subclass of: Restriction
  on property: monitors
  some values from: System Call
type: NamedIndividual
monitors: System Call
definition: Monitors system calls (operating system api functions).

Kernel Event
type: Class
subclass of: Digital Event
subclass of: Restriction
  on property: has-participant
  some values from: Kernel
definition: An event involving operations at the kernel level of an operating system, encompassing interactions with core system resources such as drivers, modules, system calls, and other privileged processes. Kernel events are critical for understanding low-level system behavior and ensuring the integrity of the operating environment.

Kernel Module
type: Class
subclass of: Object File
type: NamedIndividual
definition: A loadable kernel module (LKM) is an object file that contains code to extend the running kernel, or so-called base kernel, of an operating system. LKMs are typically used to add support for new hardware (as device drivers) and/or filesystems, or for adding system calls. When the functionality provided by a LKM is no longer required, it can be unloaded in order to free memory and other resources. Most current Unix-like systems and Microsoft Windows support loadable kernel modules, although they might use a different name for them, such as kernel loadable module (kld) in FreeBSD, kernel extension (kext) in macOS,[1] kernel extension module in AIX, kernel-mode driver in Windows NT[2] and downloadable kernel module (DKM) in VxWorks. They are also known as kernel loadable modules (or KLM), and simply as kernel modules (KMOD).
alternative label: LKM
alternative label: Loadable Kernel Module

Kernel Module Event
type: Class
subclass of: Kernel Event
subclass of: Restriction
  on property: has-participant
  some values from: Hardware Driver
subclass of: Restriction
  on property: has-participant
  some values from: Kernel Module
definition: An event involving the management of kernel modules, such as the loading or unloading of device drivers, extensions, or other dynamically linked components essential for kernel functionality.

Kernel Module Load Event
type: Class
subclass of: Kernel Module Event
definition: An event representing the loading of a kernel module, such as a device driver or dynamically linked extension, into the operating system kernel to extend or modify its capabilities.

Kernel Module Unload Event
type: Class
subclass of: Kernel Module Event
definition: An event representing the removal of a kernel module from the operating system kernel, deallocating resources and potentially altering system functionality.

Kernel Process Table
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: A data structure in the kernel which is a table containing all of the information that must be saved when the CPU switches from running one process to another in a multitasking system. It allows the operating system to track all the process's execution status, and contains the For every process managed by the kernel, there is a process control block (PCB) in the process table.

Keyboard Input Device
type: Class
subclass of: Input Device
type: NamedIndividual
definition: A computer keyboard is a typewriter-style device which uses an arrangement of buttons or keys to act as mechanical levers or electronic switches. Following the decline of punch cards and paper tape, interaction via teleprinter-style keyboards became the main input method for computers. A keyboard is also used to give commands to the operating system of a computer, such as Windows' Control-Alt-Delete combination. Although on Pre-Windows 95 Microsoft operating systems this forced a re-boot, now it brings up a system security options screen.
alternative label: Computer Keyboard
alternative label: Keyboard

Kiosk Computer
type: Class
subclass of: Shared Computer
definition: An interactive kiosk is a computer terminal featuring specialized hardware and software that provides access to information and applications for communication, commerce, entertainment, or education. Early interactive kiosks sometimes resembled telephone booths, but have been embraced by retail, food service and hospitality to improve customer service and streamline operations. Interactive kiosks are typically placed in high foot traffic settings such as shops, hotel lobbies or airports.
alternative label: Interactive Kiosk

Kurtosis
type: Class
subclass of: Distribution Properties
type: NamedIndividual
d3fend-id: D3A-KUR
definition: The measure of the "fatness" of the tails of a pmf or pdf. The fourth standardized moment of the distribution.
kb-article: ## References Wikipedia. (n.d.). Probability distribution. [Link](https://en.wikipedia.org/wiki/Probability_distribution)

LAN Access Mediation
type: Class
subclass of: Network Access Mediation
subclass of: Restriction
  on property: isolates
  some values from: Local Area Network
type: NamedIndividual
isolates: Local Area Network
kb-reference: Reference-WhatIsNetworkAccessControl
d3fend-id: D3-LAMED
definition: LAN access mediation encompasses the application of strict access control policies, systematic verification of devices, and authentication mechanisms to govern connectivity to a Local Area Network.
kb-article: ## How it works LAN Access Mediation is a network security approach that manages and controls access to a Local Area Network by using key components such as Access Control Lists (ACLs) to specify which devices are allowed or denied access, Port Security to restrict device connections to specific switch ports, RADIUS for determining the level of access or specific resources available to users or devices, and 802.1X for enforcing device authentication before granting network access. This comprehensive strategy ensures that only authorized devices and users can connect to the network, enhancing overall security.
comment: Layer 2 Enforcement

Laptop Computer
type: Class
subclass of: Personal Computer
definition: A laptop computer (also laptop), is a small, portable personal computer (PC) with a "clamshell" form factor, typically having a thin LCD or LED computer screen mounted on the inside of the upper lid of the clamshell and an alphanumeric keyboard on the inside of the lower lid. The clamshell is opened up to use the computer. Laptops are folded shut for transportation, and thus are suitable for mobile use. Its name comes from lap, as it was deemed to be placed on a person's lap when being used. Although originally there was a distinction between laptops and notebooks (the former being bigger and heavier than the latter), as of 2014, there is often no longer any difference. Today, laptops are commonly used in a variety of settings, such as at work, in education, for playing games, web browsing
alternative label: Laptop
alternative label: Notebook

Lateral Movement Technique
type: Class
subclass of: ATTACK Enterprise Technique
subclass of: Offensive Technique
subclass of: Restriction
  on property: enables
  some values from: Lateral Movement
type: NamedIndividual
enables: Lateral Movement

Legacy System
type: Class
subclass of: Digital System
type: NamedIndividual
definition: In computing, a legacy system is an old method, technology, computer system, or application program, "of, relating to, or being a previous or outdated computer system," yet still in use. Often referencing a system as "legacy" means that it paved the way for the standards that would follow it. This can also imply that the system is out of date or in need of replacement.
synonym: Legacy Digital System

Levenschtein Matching
type: Class
subclass of: Approximate String Matching
type: NamedIndividual
d3fend-id: D3A-LM
definition: The Levenshtein distance (LD) is a metric for measuring the differences between two sequences - or strings. Informally, the LD is the number of individual edits one would have to make to turn one sequence into another.
kb-article: ## References 1. Navarro, G. (2001). A guided tour to approximate string matching. _ACM Computing Surveys_, 33(1), 31-88. [Link](https://doi.org/10.1145/375360.375365)
synonym: Edit Distance

Linear Classifier
type: Class
subclass of: Classification
type: NamedIndividual
d3fend-id: D3A-LC
definition: A linear classifier is a model that makes a decision to categories a set of data points to a discrete class based on a linear combination of its explanatory variables
kb-article: ## References A Look at the Maths Behind Linear Classification. Towards Data Science. [Link](https://towardsdatascience.com/a-look-at-the-maths-behind-linear-classification-166e99a9e5fb).

Linear Logic Programming
type: Class
subclass of: Logic Programming
type: NamedIndividual
d3fend-id: D3A-LLP
definition: Linear logic programming is a form of logic programming that uses linear logic, that is, it emphasizes the use of formulas as resources.
kb-article: ## References 1. Cosmo, R. and Miller D. (2019, May 24). _Linear logic_. Stanford Encyclopedia of Philosophy. [Link](https://plato.stanford.edu/entries/logic-linear/#LinLogComSci) 2. Linear logic programming. (2023, May 16). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Logic_programming#Linear_logic_programming)

Linear Regression
type: Class
subclass of: Regression Analysis
type: NamedIndividual
d3fend-id: D3A-LR
definition: Statistical regression method used for predictive analysis by modeling the linear relationship between independent and dependent variables.
kb-article: ## How it works Takes independent variables (i.e. covariate, features, predictors, input variables) and dependent variables (i.e. response, output, “thing to be estimated”) and produces the coefficient(s) and intercept for a linear equation (e.g. (β1, β0) for y = β1x + β0) which predicts the relationship between the independent and independent variables by minimizing a cost function, Mean Squared Error, either directly in the case of univariate linear regression or by gradient descent* in the case of multivariate linear regression. ## Considerations - There are four principal assumptions required for good results using linear regression (the first letters of the four principal assumptions form the "LINE" mnemonic): - Linearity and Additivity - Independent Residuals - Normal Residual Distributions - Equal Variances (i.e. homoscedasticity) - Linear regression is a low variance/high bias model. - Optimizers like Adam, Batch, and Mini-Batch and others are available for certain applications and data sets. - A large learning ratio or training coefficient may lead to divergent behavior of the model and too small of values may lead to long run times and inefficiency. ## Verification Approach - Models are often evaluated by examining one or more of the metrics of R2, Root Mean Squared Error (RMSE), Mean Absolute Error (MAE), and Mean Absolute Percentage Error (MAPE). - While there is no generally accepted single best performance metric as a criterion, users of linear regression should consider the suitability of one or more of these metrics for assessing the performance of their model. - Use well known data sets to verify model execution. ## Validation Approach - Violating the principal assumptions of linear regression results in poor or misleading results. - Ensure data is truly representative and if there are any known biases. ## References 1. Gawali, Suvarna. “Linear Regression Algorithm to Make Predictions Easily.” Analytics Vidhya, 22 July 2022, https://www.analyticsvid…

Linear Regression Learning
type: Class
subclass of: Regression Analysis Learning
type: NamedIndividual
d3fend-id: D3A-LRL
definition: A supervised learning method that builds a linear regression model using training data.
kb-article: ## References - Gawali, Suvarna. “Linear Regression Algorithm to Make Predictions Easily.” Analytics Vidhya, 22 July 2022, https://www.analyticsvidhya.com/blog/2021/06/linear-regression-in-machine-learning/. - Nau, Robert. “Statistical Forecasting: Notes On Regression and Time Series Analysis.” Introduction to Linear Regression Analysis, Duke University Fuqua School of Business, 18 Aug. 2020, https://people.duke.edu/~rnau/regintro.htm. - Ng, Ritchie. “Evaluating a Linear Regression Model.” Ritchieng.github.io, 8 Jan. 2023, https://www.ritchieng.com/machine-learning-evaluate-linear-regression-model/. - Bochkarev, Alexei. "A New Typology Design of Performance Metrics to Measure Errors in Machine Learning Regression Algorithms", 2019, https://www.researchgate.net/publication/330661543_A_New_Typology_Design_of_Performance_Metrics_to_Measure_Errors_in_Machine_Learning_Regression_Algorithms.

Link
type: Class
subclass of: D3FEND Core
subclass of: Digital Information Bearer

Linux Clone
type: Class
subclass of: OS API Create Process
definition: Creates a child process and provides more precise control over the data shared between the parent and child processes

Linux Clone3
type: Class
subclass of: OS API Create Process
definition: Creates a child process and provides more precise control over the data shared between the parent and child processes. Newer system call.

Linux Clone3 Argument CLONE_THREAD
type: Class
subclass of: OS API Create Thread
definition: A flag parameter to the Clone3 syscall. If set, the child is placed in the same thread group as the calling process.

Linux Clone Argument CLONE_THREAD
type: Class
subclass of: OS API Create Thread
definition: A flag parameter to the Clone syscall. If set, the child is placed in the same thread group as the calling process.

Linux Connect
type: Class
subclass of: OS API Connect Socket
definition: Initiate a connection on a socket.

Linux Creat
type: Class
subclass of: OS API Create File
definition: Equivalent to calling Linux Open with flags equal to O_CREAT|O_WRONLY|O_TRUNC.

Linux Delete Module
type: Class
subclass of: OS API Unload Module
definition: Attempts to remove the unused loadable module entry identified by name. If the module has an exit function, then that function is executed before unloading the module.

Linux Execve
type: Class
subclass of: OS API Exec
definition: Executes a program by replacing the calling process with a new program, with newly initialized stack, heap, and (initialized and uninitialized) data segments. The PID stays the same.

Linux Execveat
type: Class
subclass of: OS API Exec
definition: Execute program relative to a directory file descriptor. Behavior is similar to Linux Execve.

Linux Fork
type: Class
subclass of: OS API Create Process
definition: Creates a child process with unique PID but retains parent PID as Parent Process Identifier (PPID)

Linux Init Module
type: Class
subclass of: OS API Load Module
definition: Loads an ELF image into kernel space, performs any necessary symbol relocations, initializes module parameters to values provided by the caller, and then runs the module's init function.

Linux Kill Argument SIGKILL
type: Class
subclass of: OS API Terminate Process
definition: Send SIGKILL signal to a process.

Linux Mmap
type: Class
subclass of: OS API Allocate Memory
definition: Map files or devices into memory.

Linux Mmap2
type: Class
subclass of: OS API Allocate Memory
definition: Map files or devices into memory.

Linux Munmap
type: Class
subclass of: OS API Free Memory
definition: Unmap files or devices from memory.

Linux Open Argument O_CREAT
type: Class
subclass of: OS API Create File
definition: Create a regular file.

Linux Open Argument O_RDONLY, O_WRONLY, O_RDWR
type: Class
subclass of: OS API Open File
definition: Opens a file specified by pathname.

Linux OpenAt2 Argument O_CREAT
type: Class
subclass of: OS API Create File
definition: Create a regular file. Extension of Linux Openat.

Linux OpenAt2 Argument O_RDONLY, O_WRONLY, O_RDWR
type: Class
subclass of: OS API Open File
definition: Extension of Linux Openat.

Linux OpenAt Argument O_CREAT
type: Class
subclass of: OS API Create File
definition: Create a regular file. Same functionality as Linux Open but slight differences in parameter.

Linux OpenAt Argument O_RDONLY, O_WRONLY, O_RDWR
type: Class
subclass of: OS API Open File
definition: Same functionality as Linux Open but slight differences in parameter.

Linux Pause Process
type: Class
subclass of: OS API Suspend Process
definition: Causes the calling process to sleep until a signal is delivered that either terminates the process or causes the invocation of a signal-catching function.

Linux Pause Thread
type: Class
subclass of: OS API Suspend Thread
definition: Causes the calling thread to sleep until a signal is delivered that either terminates the thread or causes the invocation of a signal-catching function.

Linux Ptrace Argument PTRACE_ATTACH
type: Class
subclass of: OS API Access Process
definition: Attach to the process specified in pid, making it a tracee of the calling process.

Linux Ptrace Argument PTRACE_CONT
type: Class
subclass of: OS API Resume Process
definition: Restart the stopped tracee process.

Linux Ptrace Argument PTRACE_GETREGS
type: Class
subclass of: OS API Save Registers
definition: Copy the tracee's general-purpose or floating-point registers, respectively, to the address data in the tracer.

Linux Ptrace Argument PTRACE_INTERRUPT
type: Class
subclass of: OS API Suspend Process
definition: Stops a tracee.

Linux Ptrace Argument PTRACE_PEEKTEXT
type: Class
subclass of: OS API Read Memory
definition: Read a word at the address addr in the tracee's memory, returning the word as the result of the ptrace() call.

Linux Ptrace Argument PTRACE_POKETEXT
type: Class
subclass of: OS API Write Memory
definition: Copy the word data to the address addr in the tracee's memory.

Linux Ptrace Argument PTRACE_SETREGS
type: Class
subclass of: OS API Set Registers
definition: Modify the tracee's general-purpose or floating-point registers, respectively, from the address data in the tracer.

Linux Ptrace Argument PTRACE_DETACH
type: Class
subclass of: OS API Resume Process
definition: Restart the stopped tracee as for PTRACE_CONT, but first detach from it.

Linux Ptrace Argument PTRACE_TRACEME
type: Class
subclass of: OS API Trace Process
definition: Indicates that the process is to be traced by its parent.

Linux Read
type: Class
subclass of: OS API Read File
definition: Read from a file descriptor.

Linux Readv
type: Class
subclass of: OS API Read File
definition: Read data into multiple buffers.

Linux Rename
type: Class
subclass of: OS API Move File
definition: Change the name or location of a file

Linux Renameat
type: Class
subclass of: OS API Move File
definition: Change the name or location of a file. Different parameter handling than Linux Rename.

Linux Renameat2
type: Class
subclass of: OS API Move File
definition: Change the name or location of a file. Additional flags argument.

Linux Socket
type: Class
subclass of: OS API Create Socket
definition: Create an endpoint for communication.

Linux Socketcall Argument SYS_CONNECT
type: Class
subclass of: OS API Connect Socket

Linux Socketcall Argument SYS_SOCKET
type: Class
subclass of: OS API Create Socket

Linux Time
type: Class
subclass of: OS API Get System Time
definition: Get time in seconds.

Linux Unlink
type: Class
subclass of: OS API Delete File
definition: Delete a name and possibly the file it refers to.

Linux Unlinkat
type: Class
subclass of: OS API Delete File
definition: Delete a name and possibly the file it refers to. Different parameter handling than Linux Unlink

Linux Vfork
type: Class
subclass of: OS API Create Process
definition: Create child process that temp suspends parent process until it terminates

Linux Write
type: Class
subclass of: OS API Write File
definition: Write to a file descriptor.

Linux Writev
type: Class
subclass of: OS API Write File
definition: Write data into multiple buffers.

Linux _Exit
type: Class
subclass of: OS API Terminate Process
definition: Terminate the calling process.

Load Library Event
type: Class
subclass of: Process Event
subclass of: Restriction
  on property: has-participant
  some values from: Shared Library File
definition: An event where a process dynamically loads a library or module into its memory space, extending its capabilities.

Load Module
type: Class
subclass of: System Call
subclass of: Restriction
  on property: loads
  some values from: Hardware Driver
subclass of: Restriction
  on property: loads
  some values from: Kernel Module
type: NamedIndividual
loads: Hardware Driver
loads: Kernel Module
definition: A system call that loads a driver or extension into the kernel.

Local Account Monitoring
type: Class
subclass of: User Behavior Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Local User Account
type: NamedIndividual
analyzes: Local User Account
kb-reference: Reference-AuditUserAccountManagement
kb-reference: Reference-CAR-2016-04-004 SuccessfulLocalAccountLogin
kb-reference: Reference-OSQueryWindowsUserCollectionCode
d3fend-id: D3-LAM
definition: Analyzing local user accounts to detect unauthorized activity.

Local Area Network
type: Class
subclass of: Network
subclass of: Restriction
  on property: may-contain
  some values from: Host
type: NamedIndividual
may-contain: Host
definition: A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building and has its network equipment and interconnects locally managed. Ethernet and Wi-Fi are the two most common transmission technologies in use for local area networks. Historical technologies include ARCNET, Token ring, and AppleTalk.
alternative label: LAN

Local Area Network Traffic
type: Class
subclass of: Intranet Network Traffic
type: NamedIndividual
definition: Intranet local area network (LAN) traffic is network traffic that does not cross a given network's boundaries; where that network is defined as a LAN.

Local Authentication Service
type: Class
subclass of: Authentication Service
subclass of: System Service Software
definition: A local authentication service running on a host can authenticate a user logged into just that local host computer.

Local Authorization Service
type: Class
subclass of: Authorization Service
subclass of: System Service Software
definition: A local authorization service running on a host can authorize a user logged into just that local host computer.

Local File Access Mediation
type: Class
subclass of: System Call Filtering
subclass of: Restriction
  on property: filters
  some values from: Open File
type: NamedIndividual
filters: Open File
kb-reference: Reference-FileAndFolderPermissions
d3fend-id: D3-LFAM
definition: Restricting access to a local file by configuring operating system functionality.
synonym: Local File Access Control
comment: Replaces d3-LFP

Local File Permissions
type: Class
subclass of: Access Policy Administration
subclass of: Restriction
  on property: restricts
  some values from: Directory
subclass of: Restriction
  on property: restricts
  some values from: File
type: NamedIndividual
kb-reference: Reference-FileAndFolderPermissions
restricts: Directory
restricts: File
d3fend-id: D3-LFP
definition: Restricting access to a local file by configuring operating system functionality.

Local Resource
type: Class
subclass of: Resource
type: NamedIndividual
definition: In computing, a system resource, or simply resource, is any physical or virtual component of limited availability within a computer system. Every device connected to a computer system is a resource. Every internal system component is a resource. Virtual system resources include files (concretely file handles), network connections (concretely network sockets), and memory areas. Managing resources is referred to as resource management, and includes both preventing resource leaks (releasing a resource when a process has finished using it) and dealing with resource contention (when multiple processes wish to access a limited resource).
alternative label: System Resource

Local Resource Access
type: Class
subclass of: Resource Access
subclass of: Restriction
  on property: accesses
  some values from: Local Resource
type: NamedIndividual
accesses: Local Resource
definition: Ephemeral digital artifact comprising a request of a local resource and any response from that resource.
alternative label: Endpoint Resource Access

Local User Account
type: Class
subclass of: User Account
type: NamedIndividual
definition: A user account on a given host is a local user account for that specific host.

Log
type: Class
subclass of: D3FEND Core
subclass of: Digital Information Bearer
type: NamedIndividual
definition: A record of events in the order of their occurrence.
alternative label: Chronology

Log File
type: Class
subclass of: File
subclass of: Restriction
  on property: contains
  some values from: Log
type: NamedIndividual
contains: Log
definition: A log file is a file that records either events that occur in an operating system or other software runs, or messages between different users of a communication software. Logging is the act of keeping a log. In the simplest case, messages are written to a single log file. A transaction log is a file (i.e., log) of the communications between a system and the users of that system, or a data collection method that automatically captures the type, content, or time of transactions made by a person from a terminal with that system. For Web searching, a transaction log is an electronic record of interactions that have occurred during a searching episode between a Web search engine and users searching for information on that Web search engine. Many operating systems, software frameworks and programs include a logging system. A widely used logging standard is syslog, defined in Internet Engineering Task Force (IETF) RFC 5424). The syslog standard enables a dedicated, standardized subsystem to generate, filter, record, and analyze log messages. This relieves software developers of having to design and code their own ad hoc logging systems.

Log Message Function
type: Class
subclass of: Subroutine
definition: Produces an entry in a log.

Logic Programming
type: Class
subclass of: Symbolic AI
type: NamedIndividual
d3fend-id: D3A-LP
definition: Logic programming is a programming paradigm which is largely based on formal logic.
kb-article: ## How it works Any program written in a logic programming language is a set of sentences in logical form, expressing facts and rules about some problem domain. Major logic programming language families include Prolog, answer set programming (ASP) and Datalog. In all of these languages, rules are written in the form of clauses: H :- B_1, ..., B_n. ## References 1. Logic programming. (2023, May 29). In _Wikipedia_. [Link]( https://en.wikipedia.org/wiki/Logic_programming)

Logical Link
type: Class
subclass of: Link
type: NamedIndividual

Logical Link Mapping
type: Class
subclass of: Network Mapping
subclass of: Restriction
  on property: maps
  some values from: Logical Link
subclass of: Restriction
  on property: maps
  some values from: Network
subclass of: Restriction
  on property: maps
  some values from: Network Node
type: NamedIndividual
kb-reference: Reference-LibreNMSDocsNetworkMapExtension
maps: Logical Link
maps: Network
maps: Network Node
d3fend-id: D3-LLM
definition: Logical link mapping creates a model of existing or previous node-to-node connections using network-layer data or metadata.

Logical Rules
type: Class
subclass of: Symbolic Logic
type: NamedIndividual
d3fend-id: D3A-LR
definition: A logical rule matches event data or set of values to a conditional expression and results in the determination of a truth value, which may be used to determine the next action or step to take.
kb-article: ## How it works Logic rules define a set of patterns that in some patterns must match input data. If the the conditions are met, then the rule will "fire" and some action will be taken, usually notifying a person or another system that the event being monitored needs further processing or attention. ## Key Test Considerations - **Performance (Accuracy)** Identify instances in data where rule is expected to be triggered. Implement traceability and metrics for individual rule performance. Traceability of cases could be implemented as unit tests or as part of a fine-grained classification performance platform. For simple rule-based matching systems with many rules, individual rules may be unused or may create unusually high false positives (or false negatives relative to expectation. - **Performance (Computational)** Generate model performance measures (see Classification Performance Measures), esp. a confusion matrix for each rule and identify outliers and relative contribution of rule to overall performance. ## References 1. Event condition action. (2019, Nov 21). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Event_condition_action). 2. Business rule. (2023, April 10). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Business_rule). 3. YARA. (2023, June 5). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/YARA).

Login Session
type: Class
subclass of: Session
type: NamedIndividual
definition: In computing, a login session is the period of activity between a user logging in and logging out of a (multi-user) system. This includes local login sessions, where a user has direct physical access to a computer, as well as domain login sessions, where a user logs into a computer that is part of a network domain.
alternative label: Logon Session

Logistic Regression
type: Class
subclass of: Regression Analysis
type: NamedIndividual
d3fend-id: D3A-LR
definition: Logistic regression is estimating the parameters of a logistic model.
kb-article: ## References Wikipedia. (n.d.). Logistic regression. [Link](https://en.wikipedia.org/wiki/Logistic_regression)

Logistic Regression Learning
type: Class
subclass of: Regression Analysis Learning
type: NamedIndividual
d3fend-id: D3A-LRL
definition: A supervised learning method that builds a logistic regression model using training data.
kb-article: ## References Wikipedia. (n.d.). Logistic regression. [Link](https://en.wikipedia.org/wiki/Logistic_regression)

Logoff Event
type: Class
subclass of: Authentication Event
subclass of: Restriction
  on property: has-participant
  some values from: Session
subclass of: Restriction
  on property: preceded-by
  some values from: Logon Event
definition: An authentication event where an active session is conclusively terminated, resulting in the cessation of access and deallocation of resources associated with the session, ensuring that the connection to the system, application, or resource no longer exists.

Logon Event
type: Class
subclass of: Authentication Event
subclass of: Restriction
  on property: has-participant
  some values from: Session
definition: An authentication event where a new session is initiated, signifying the successful validation of credentials and establishment of an authorized connection to a system, application, or resource. This marks the beginning of the subject’s authenticated interaction with the system.

Logon User
type: Class
subclass of: System Call
subclass of: Restriction
  on property: authenticates
  some values from: User Account
type: NamedIndividual
authenticates: User Account

Long Short-term Memory
type: Class
subclass of: Recurrent Neural Network
type: NamedIndividual
d3fend-id: D3A-LSTM
definition: Unlike standard feedforward neural networks, LSTM has feedback connections. Such a recurrent neural network (RNN) can process not only single data points (such as images), but also entire sequences of data (such as speech or video). This characteristic makes LSTM networks ideal for processing and predicting data
kb-article: ## References Wikipedia. (2021, September 29). Long short-term memory. [Link](https://en.wikipedia.org/wiki/Long_short-term_memory)

MAC Address
type: Class
subclass of: Identifier
subclass of: Restriction
  on property: identifies
  some values from: Network Interface Card
type: NamedIndividual
identifies: Network Interface Card
definition: A media access control address (MAC address) is a unique identifier assigned to a network interface controller (NIC) for use as a network address in communications within a network segment.

MacOS Keychain
type: Class
subclass of: Password Store
type: NamedIndividual
definition: Keychain is the password management system in macOS, developed by Apple. It was introduced with Mac OS 8.6, and has been included in all subsequent versions of the operating system, now known as macOS. A Keychain can contain various types of data: passwords (for websites, FTP servers, SSH accounts, network shares, wireless networks, groupware applications, encrypted disk images), private keys, certificates, and secure notes.
alternative label: Keychain

Machine Learning
type: Class
subclass of: Analytic Technique
type: NamedIndividual
d3fend-id: D3A-ML
definition: Machine learning techniques are computational methods that combine statistics, probability, and optimization to make accurate predictions and/or improve performance.
kb-article: ## References Machine learning." Wikipedia. [Link](https://en.wikipedia.org/wiki/Machine_learning).

Mail Network Traffic
type: Class
subclass of: Network Traffic
subclass of: Restriction
  on property: contains
  some values from: Email
type: NamedIndividual
contains: Email
definition: Mail traffic is network traffic that uses a standard mail transfer protocol.

Mail Server
type: Class
subclass of: Server
subclass of: Restriction
  on property: runs
  some values from: Message Transfer Agent
type: NamedIndividual
runs: Message Transfer Agent
definition: Within the Internet email system, a message transfer agent or mail transfer agent (MTA) or mail relay is software that transfers electronic mail messages from one computer to another using SMTP. The terms mail server, mail exchanger, and MX host are also used in some contexts. Messages exchanged across networks are passed between mail servers, including any attached data files (such as images, multimedia or documents). These servers also often keep mailboxes for email. Access to this email by end users is typically either via webmail or an email client.
alternative label: Email Server Resource
alternative label: MTA
alternative label: MX Host
alternative label: Mail Exchanger
alternative label: Mail transfer agent
alternative label: Message transfer agent

Mail Service
type: Class
subclass of: Network Service
definition: A mail service provides the ability to send and receive mail across a computer network. The mail service runs on message transfer agents (i.e., mail servers) and is accessed by users through an email client.
alternative label: Email Service

Matching
type: Class
subclass of: Analytical Purpose

Mathematical Function
type: Class
subclass of: Subroutine
type: NamedIndividual
definition: Computes mathematical expressions.

Maximum-margin Learning
type: Class
subclass of: Intrinsically Semi-supervised Learning
type: NamedIndividual
d3fend-id: D3A-MML
definition: Maximum-margin classifiers attempt to maximize the distance between the given data points and the decision boundary
kb-article: ## References Engelen, S., & Hoos, H. (2020). A survey on semi-supervised learning. Machine Learning, 109(2), 299-337. [Link](https://link.springer.com/article/10.1007/s10994-019-05855-6). Support Vector Machines for Machine Learning. [Link](https://machinelearningmastery.com/support-vector-machines-for-machine-learning/#:~:text=The%20distance%20between%20the%20line,called%20the%20Maximal%2DMargin%20hyperplane.)

Mean
type: Class
subclass of: Central Tendency
type: NamedIndividual
d3fend-id: D3A-MEA
definition: The sum of all measurements divided by the number of observations in the data set.
kb-article: ## References Wikipedia. (n.d.). Central tendency. [Link](https://en.wikipedia.org/wiki/Central_tendency)

Mean Absolute Deviation
type: Class
subclass of: Average Absolute Deviation
type: NamedIndividual
d3fend-id: D3A-MAD
definition: The mean absolute deviation (MAD), also referred to as the "mean deviation" or sometimes "average absolute deviation", is the mean of the data's absolute deviations around the data's mean: the average (absolute) distance from the mean.
kb-article: ## References Wikipedia. (n.d.). Average absolute deviation. [Link](https://en.wikipedia.org/wiki/Average_absolute_deviation)
synonym: MAD

Media Generation
type: Class
subclass of: Media Generation
disjoint with: Simulation

Media Server
type: Class
subclass of: Server
definition: A media server is a computer appliance or an application software that stores digital media (video, audio or images) and makes it available over a network. Media servers range from servers that provide video on demand to smaller personal computers or NAS (Network Attached Storage) for the home.

Median
type: Class
subclass of: Central Tendency
type: NamedIndividual
d3fend-id: D3A-MED
definition: The middle value that separates the higher half from the lower half of the data set. The median and the mode are the only measures of central tendency that can be used for ordinal data, in which values are ranked relative to each other but are not measured absolutely.
kb-article: ## References Wikipedia. (n.d.). Central tendency. [Link](https://en.wikipedia.org/wiki/Central_tendency)

Median Absolute Deviation
type: Class
subclass of: Average Absolute Deviation
type: NamedIndividual
d3fend-id: D3A-MAD
definition: The median absolute deviation (also MAD) is the median of the absolute deviation from the median.
kb-article: ## References Wikipedia. (n.d.). Average absolute deviation. [Link](https://en.wikipedia.org/wiki/Average_absolute_deviation)

Memory Address
type: Class
subclass of: Digital Information
subclass of: Restriction
  on property: addresses
  some values from: Memory Word
type: NamedIndividual
addresses: Memory Word
definition: In computing, a memory address is a reference to a specific memory location used at various levels by software and hardware.

Memory Address Space
type: Class
subclass of: Address Space
subclass of: Restriction
  on property: contains
  some values from: Memory Address
type: NamedIndividual
contains: Memory Address
definition: A memory address space is a space containing memory addresses.

Memory Allocation Event
type: Class
subclass of: Memory Event
definition: An event representing the allocation of memory resources to a process, providing it with the capacity to store data or execute instructions.

Memory Allocation Function
type: Class
subclass of: Subroutine
subclass of: Restriction
  on property: invokes
  some values from: Allocate Memory
type: NamedIndividual
invokes: Allocate Memory
definition: Reserves memory for a running process to use.

Memory Block
type: Class
subclass of: Memory Extent
subclass of: Restriction
  on property: contains
  some values from: Memory Word
subclass of: Restriction
  on property: may-contain
  some values from: Record
type: NamedIndividual
contains: Memory Word
may-contain: Record
definition: In computing (specifically data transmission and data storage), a block, sometimes called a physical record, is a sequence of bytes or bits, usually containing some whole number of records, having a maximum length; a block size. Data thus structured are said to be blocked. The process of putting data into blocks is called blocking, while deblocking is the process of extracting data from blocks. Blocked data is normally stored in a data buffer and read or written a whole block at a time.

Memory Block Start Validation
type: Class
subclass of: Pointer Validation
subclass of: Restriction
  on property: hardens
  some values from: Memory Free Function
type: NamedIndividual
hardens: Memory Free Function
kb-reference: Reference-CManualPointerArithmetic GNU
d3fend-id: D3-MBSV
definition: Ensuring that a pointer accurately references the beginning of a designated memory block.
kb-article: ## How it Works Ensure that a pointer is referencing the beginning of the intended block before using. ## Considerations Be careful with pointer arithmetic.

Memory Boundary Tracking
type: Class
subclass of: Operating System Monitoring
subclass of: Restriction
  on property: analyzes
  some values from: Process Code Segment
type: NamedIndividual
analyzes: Process Code Segment
kb-reference: Reference-InferentialExploitAttemptDetection CrowdstrikeInc
d3fend-id: D3-MBT
definition: Analyzing a call stack for return addresses which point to unexpected memory locations.
kb-article: ## How it works This technique monitors for indicators of whether a return address is outside memory previously allocated for an object (i.e. function, module, process, or thread). If so, code that the return address points to is treated as malicious code. ## Considerations Kernel malware can manipulate memory contents, for example modifying pointers to hide processes, and thereby impact the accuracy of memory allocation information used to perform the analysis.

Memory Deletion Event
type: Class
subclass of: Memory Event
definition: An event marking the release or deallocation of memory resources, reclaiming them for reuse within the system.

Memory Device Event
type: Class
subclass of: Hardware Device Event
subclass of: Restriction
  on property: has-participant
  some values from: Primary Storage
definition: An event describing activity in primary storage devices, such as DRAM or SRAM memory initialization, reconfiguration, or failures.

Memory Event
type: Class
subclass of: Digital Event
subclass of: Restriction
  on property: has-participant
  some values from: Memory Address
subclass of: Restriction
  on property: has-participant
  some values from: Memory Extent
definition: An event capturing operations on the memory resources of a system, encompassing allocation, modification, access, protection, or deallocation.

Memory Extent
type: Class
subclass of: Digital Information

Memory Free Function
type: Class
subclass of: Subroutine
subclass of: Restriction
  on property: invokes
  some values from: Free Memory
type: NamedIndividual
invokes: Free Memory
definition: Releases previously reserved memory associated with a process.

Memory Management Unit
type: Class
subclass of: Processor Component
subclass of: Restriction
  on property: contains
  some values from: Translation Lookaside Buffer
subclass of: Restriction
  on property: creates
  some values from: Virtual Address
subclass of: Restriction
  on property: manages
  some values from: Page Table
subclass of: Restriction
  on property: manages
  some values from: Storage
type: NamedIndividual
contains: Translation Lookaside Buffer
creates: Virtual Address
manages: Page Table
manages: Storage
definition: A computer’s memory management unit (MMU) is the physical hardware that handles its virtual memory and caching operations. The MMU is usually located within the computer’s central processing unit (CPU), but sometimes operates in a separate integrated chip (IC).

Memory Management Unit Component
type: Class
subclass of: Hardware Device

Memory Map Event
type: Class
subclass of: Memory Event
subclass of: Restriction
  on property: has-participant
  some values from: Virtual Memory Space
definition: An event representing the mapping of memory regions into a process's virtual address space, enabling efficient access to shared or reserved memory.

Memory Modification Event
type: Class
subclass of: Memory Event
definition: An event where a process modifies allocated memory, potentially altering its content, behavior, or state.

Memory Pool
type: Class
subclass of: Memory Extent
subclass of: Restriction
  on property: contains
  some values from: Memory Block
type: NamedIndividual
contains: Memory Block
definition: Memory pools, also called fixed-size blocks allocation, is the use of pools for memory management… preallocating a number of memory blocks with the same size called the memory pool. The application can allocate, access, and free blocks represented by handles at run time.

Memory Protection Unit
type: Class
subclass of: Processor Component
type: NamedIndividual

Memory Read Event
type: Class
subclass of: Memory Event
definition: An event where a process retrieves data from a specific memory address, either from its own allocated space or that of another process.

Memory Word
type: Class
subclass of: Memory Extent
type: NamedIndividual
definition: A memory word is the natural unit of data used by a particular computer processor design; a fixed-size piece of data handled as a unit by the instruction set or the hardware of the processor.

Memory Write Event
type: Class
subclass of: Memory Event
definition: An event where a process writes data to a memory address, storing new information or updating existing content.

Message Analysis
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Detect
type: NamedIndividual
enables: Detect
d3fend-id: D3-MA
definition: Analyzing email or instant message content to detect unauthorized activity.
kb-article: ## Technique Overview Email and messaging are frequently used to deliver malicious content to targets. These enterprise capabilities are used to deliver software exploits or social engineering tricks. If the recipient of a message trusts the sender, attackers can avoid escalating suspicion. Emails and messages are also complex data structures. They contain files and links, and complex data encodings which vary region to region. Thus the defensive techniques used to analyze emails and messages are highly varied ranging from deep content analysis and execution to social network graph-style analytics to analyze trust or risk.
synonym: Electronic Message Analysis
synonym: Email Or Messaging Analysis

Message Authentication
type: Class
subclass of: Message Hardening
subclass of: Restriction
  on property: authenticates
  some values from: User to User Message
type: NamedIndividual
authenticates: User to User Message
kb-reference: Reference-DomainKeysIdentifiedMail-Signatures-IETF
kb-reference: Reference-SecureMultipurposeInternetMailExtensionsMIME-Version3.1
d3fend-id: D3-MAN
definition: Authenticating the sender of a message and ensuring message integrity.
kb-article: ## How it works ### Digital Signature Digital signatures are used to verifying a message is from the expected sender. In email, Secure/Multipurpose Internet Mail Extensions (S/MIME) protocol is typically used to digitally sign messages. A hash value of the sender's message is created and encrypted with the sender's private key to create a digital signature. The message and the digital signature are sent to the recipient where the sender's public key is used to decrypt the digital signature and compute the hash of the message. The computed hash is compared with the hash from the received message, and any difference in the hash values signify the message did not originate from the sender and has been alerted in transit. ### Message Authentication Code (MAC) MAC is a fixed size string that is appended to a message to provide message authentication and integrity. The sender MAC signing algorithm takes as input a secret symmetric key shared between sender and recipient and the message to calculate a short tag that is appended to the message. The recipient receives the message with the appended tag, and a MAC verification algorithm is run using the symmetric key to verify the message came from the stated sender and ensure the message has not been tampered with. ## Considerations - Public keys associated with digital signatures should be verified by a Certification Authority (CA) to prevent impersonation. The CA verifies the owner of a public key and puts the sender's identity and public key into a certificate that is signed by the CA. - Digital signatures provide non-repudiation where a third party can verify the authenticity of the message using the sender's digital certificate signed by the CA. - Symmetric keys must be exchanged securely via a private channel and management of new symmetric keys are needed for each pair of participants wishing to exchange messages.

Message Encryption
type: Class
subclass of: Message Hardening
subclass of: Restriction
  on property: encrypts
  some values from: User to User Message
type: NamedIndividual
encrypts: User to User Message
kb-reference: Reference-SecureMultipurposeInternetMailExtensionsMIME-Version3.1
d3fend-id: D3-MENCR
definition: Encrypting a message body using a cryptographic key.
kb-article: ## How it works ### Asymmetric Cryptography Asymmetric encryption is typically accomplished using public and private key certificates based on the X.509 standard. The sender encrypts messages using the recipient's public key and the receipt decrypts the message using their private key. Standards that can be used to implement message encryption include S/MIME (Secure/Multipurpose Internet Mail Extensions) and PGP. ### Symmetric Cryptography Symmetric encryption uses the same cryptographic key by both the sender and receiver to encrypt and decrypt a message. Asymmetric key exchange protocols such as Diffie-Hellman can be used to share the cryptographic key with the recipient. ## Considerations - Separate configuration settings to enable message encryption are often needed for each messenger client (e.g. webmail, desktop client, mobile). - Continuous monitoring to ensure private keys are not compromised and the certificate authority (CA) is trusted. - Secure transfer of private keys between multiple devices.

Message Hardening
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Harden
type: NamedIndividual
enables: Harden
d3fend-id: D3-MH
definition: Email or Messaging Hardening includes measures taken to ensure the confidentiality and integrity of user to user computer messages.
synonym: Email Or Messaging Hardening

Message Transfer Agent
type: Class
subclass of: Mail Service
type: NamedIndividual
definition: A message transfer agent or mail transfer agent (MTA) or mail relay is software that transfers electronic mail messages from one computer to another using a client-server application architecture. An MTA implements both the client (sending) and server (receiving) portions of the Simple Mail Transfer Protocol.
alternative label: MTA
alternative label: Mail Transfer Agent

Metadata
type: Class
subclass of: Digital Information
definition: Metadata is "data [information] that provides information about other data". Three distinct types of metadata exist: structural metadata, descriptive metadata, and administrative metadata. Structural metadata is data about the containers of data. For instance a "book" contains data, and data about the book is metadata about that container of data. Descriptive metadata uses individual instances of application data or the data content.

Microcode
type: Class
subclass of: Firmware
definition: Microcode is a computer hardware technique that interposes a layer of organization between the CPU hardware and the programmer-visible instruction set architecture of the computer. As such, the microcode is a layer of hardware-level instructions that implement higher-level machine code instructions or internal state machine sequencing in many digital processing elements.

Microsoft HTML Application
type: Class
subclass of: HTML File
subclass of: Restriction
  on property: may-contain
  some values from: Executable Script
type: NamedIndividual
may-contain: Executable Script

Mobile Phone
type: Class
subclass of: Personal Computer
definition: A mobile phone, cellular phone, cell phone, cellphone or hand phone, sometimes shortened to simply mobile, cell or just phone, is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area. The radio frequency link establishes a connection to the switching systems of a mobile phone operator, which provides access to the public switched telephone network (PSTN). Modern mobile telephone services use a cellular network architecture and, therefore, mobile telephones are called cellular telephones or cell phones in North America. In addition to telephony, digital mobile phones (2G) support a variety of other services, such as text messaging, MMS, email, Internet access, short-range wireless communications (infrared,
alternative label: Cellphone
alternative label: Cellular Phone

Modal Logic
type: Class
subclass of: Symbolic AI
type: NamedIndividual
d3fend-id: D3A-ML
definition: Modal logic is a collection of formal systems developed to represent statements about necessity and possibility. It plays a major role in philosophy of language, epistemology, metaphysics, and natural language semantics.
kb-article: ## References 1. Modal logic. (2023, June 4). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Modal_logic)

Mode
type: Class
subclass of: Central Tendency
type: NamedIndividual
d3fend-id: D3A-MOD
definition: The most frequent value in the data set. This is the only central tendency measure that can be used with nominal data, which have purely qualitative category assignments.
kb-article: ## References Wikipedia. (n.d.). Central tendency. [Link](https://en.wikipedia.org/wiki/Central_tendency)

Model
type: Class
subclass of: Defensive Tactic
type: NamedIndividual
type: Defensive Tactic
definition: The model tactic is used to apply security engineering, vulnerability, threat, and risk analyses to digital systems. This is accomplished by creating and maintaining a common understanding of the systems being defended, the operations on those systems, actors using the systems, and the relationships and interactions between these elements.
display-order: -1
display-priority: 1

Model-based Policy Optimization
type: Class
subclass of: Model-based Reinforcement Learning
type: NamedIndividual
d3fend-id: D3A-MBPO
definition: Model-based policy optimization (MBPO) is a model-based, online, off-policy reinforcement learning algorithm. For more information on the different types of reinforcement learning agents
kb-article: ## References MBPO Agents. MathWorks. [Link](https://www.mathworks.com/help/reinforcement-learning/ug/mbpo-agents.html).

Model-based Reinforcement Learning
type: Class
subclass of: Reinforcement Learning
type: NamedIndividual
d3fend-id: D3A-MBRL
definition: Model-based Reinforcement Learning refers to learning optimal behavior indirectly by learning a model of the environment by taking actions and observing the outcomes that include the next state and the immediate reward. The models predict the outcomes of actions and are used in lieu of or in addition to interaction with the environment to learn optimal policies.
kb-article: ## References Model-Based Reinforcement Learning. In *Encyclopedia of Machine Learning*, pp. 642-644. Springer, 2010. [Link](https://link.springer.com/referenceworkentry/10.1007/978-0-387-30164-8_556#:~:text=Model%2Dbased%20Reinforcement%20Learning%20refers,state%20and%20the%20immediate%20reward).

Model-based Value Iteration
type: Class
subclass of: Model-based Reinforcement Learning
type: NamedIndividual
d3fend-id: D3A-MBVI
definition: Value Iteration effectively reducesthe evaluation stage down to a single sweep of the states. Additionally, to improve things further, it combines the Policy Evaluation and Policy Improvement stages into a single update.
kb-article: ## References Policy and Value Iteration. Towards Data Science. [Link](https://towardsdatascience.com/policy-and-value-iteration-78501afb41d2).
synonym: MBVI

Model-free Reinforcement Learning
type: Class
subclass of: Reinforcement Learning
type: NamedIndividual
d3fend-id: D3A-MFRL
definition: In reinforcement learning (RL), a model-free algorithm (as opposed to a model-based one) is an algorithm which does not use the transition probability distribution (and the reward function) associated with the Markov decision process (MDP),which, in RL, represents the problem to be solved. The transition probability distribution (or transition model) and the reward function are often collectively called the "model" of the environment (or MDP), hence the name "model-free". A model-free RL algorithm can be thought of as an "explicit" trial-and-error algorithm. An example of a model-free algorithm is Q-learning.
kb-article: ## References Model-free (reinforcement learning). Wikipedia. [Link](https://en.wikipedia.org/wiki/Model-free_(reinforcement_learning)).)

Modem
type: Class
subclass of: Computer Network Node
definition: A modem -- a portmanteau of "modulator-demodulator" -- is a hardware device that converts data into a format suitable for a transmission medium so that it can be transmitted from one computer to another (historically along telephone wires). A modem modulates one or more carrier wave signals to encode digital information for transmission and demodulates signals to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded reliably to reproduce the original digital data. Modems can be used with almost any means of transmitting analog signals from light-emitting diodes to radio. A common type of modem is one that turns the digital data of a computer into modulated electrical signal for transmission over telephone lines and demodulated by another modem at the receiver side to recover the digital data.

Moments
type: Class
subclass of: Distribution Properties
type: NamedIndividual
d3fend-id: D3A-MOM
definition: With a probability distribution function, the the first moment is the expected value, the second central moment is the variance, the third standardized moment is the skewness, and the fourth standardized moment is the kurtosis.
kb-article: ## References Wikipedia. (n.d.). Moment (mathematics). [Link](https://en.wikipedia.org/wiki/Moment_(mathematics))

Mouse Input Device
type: Class
subclass of: Input Device
definition: A computer mouse (plural mice or mouses) is a hand-held pointing device that detects two-dimensional motion relative to a surface. This motion is typically translated into the motion of a pointer on a display, which allows a smooth control of the graphical user interface of a computer. In addition to moving a cursor, computer mice have one or more buttons to allow operations such as selection of a menu item on a display. Mice often also feature other elements, such as touch surfaces and scroll wheels, which enable additional control and dimensional input.
alternative label: Computer Mouse

Move File
type: Class
subclass of: System Call
subclass of: Restriction
  on property: modifies
  some values from: File System Metadata
type: NamedIndividual
modifies: File System Metadata
definition: A system call to rename or move a file. Linux's rename() is an example of this kind of system call. Another way of handling it is to call a copy file system call followed by a delete file system call.
alternative label: Rename File

Moving Average Model
type: Class
subclass of: Time Series Analysis
type: NamedIndividual
d3fend-id: D3A-MAM
definition: the moving-average model (MA model) is an approach for modeling univariate time series and specifies that the output variable is cross-correlated with a non-identical to itself random-variable.
kb-article: ## Refrences Wikipedia. (n.d.). Moving average model. [Link](https://en.wikipedia.org/wiki/Moving_average_model)
synonym: MA Model

Multi-factor Authentication
type: Class
subclass of: Agent Authentication
subclass of: Restriction
  on property: uses
  some values from: Credential
type: NamedIndividual
kb-reference: Reference-MethodAndApparatusForUtilizingATokenForResourceAccess RsaSecurityInc.
uses: Credential
d3fend-id: D3-MFA
definition: Requiring proof of two or more pieces of evidence in order to authenticate a user.
kb-article: ## How it works When logging into an account users present two or more credentials that fall into different categories: something you know (password or PIN), something you have (smart card or phone), or something you are (fingerprint). ## Considerations MFA configuration steps may vary across accounts and in some cases left up to users to activate and implement.

Multiclass Classification
type: Class
subclass of: Classifying

Multilayer Perceptron Classification
type: Class
subclass of: Artificial Neural Network Classification
type: NamedIndividual
d3fend-id: D3A-MPC
definition: A multilayer perceptron (MLP) is a fully connected class of feedforward artificial neural network (ANN).An MLP consists of at least three layers of nodes: an input layer, a hidden layer and an output layer.
kb-article: ## References Multilayer perceptron. Wikipedia. [Link](https://en.wikipedia.org/wiki/Multilayer_perceptron).

Multimedia Document File
type: Class
subclass of: Document File
definition: Digital video files which often contain audio.

Multiple Regression
type: Class
subclass of: Regression Analysis
type: NamedIndividual
d3fend-id: D3A-MR
definition: Multiple (linear) regression attempts to model the relationship between two or more explanatory variables and a response variable by fitting a linear equation to observed data.
kb-article: ## References Yale University Department of Statistics. (1997-98). Linear regression and multivariate analysis. [Link](http://www.stat.yale.edu/Courses/1997-98/101/linmult.htm)
synonym: Multiple Linear Regression

Multiple Regression Learning
type: Class
subclass of: Regression Analysis Learning
type: NamedIndividual
d3fend-id: D3A-MRL
definition: A supervised learning method that builds a multiple regression model using training data.
kb-article: ## References Yale University Department of Statistics. (1997-98). Linear regression and multivariate analysis. [Link](http://www.stat.yale.edu/Courses/1997-98/101/linmult.htm)

Multivariate Analysis
type: Class
subclass of: Statistical Method
type: NamedIndividual
d3fend-id: D3A-MA
definition: Multivariate statistics encompassed the simultaneous observation and analysis of more than one outcome variable, i.e., multivariate random variables.
kb-article: ## References Wikipedia. (n.d.). Multivariate statistics. [Link](https://en.wikipedia.org/wiki/Multivariate_statistics)

NIST Control
type: Class
subclass of: External Control
subclass of: Restriction
  on property: member-of
  some values from: NIST SP 800-53 Control Catalog

NIST SP 800-53 Control Catalog
type: Class
subclass of: Control Catalog
subclass of: Restriction
  on property: has-member
  some values from: NIST Control
definition: A NIST SP 800-53 control catalog provides the entire set of security and privacy controls for a version of NIST SP 800-53.

NTFS Hard Link
type: Class
subclass of: Hard Link
subclass of: NTFS Link
definition: An NTFS hard link points to another file, and files share the same MFT entry (inode), in the same filesystem.

NTFS Junction Point
type: Class
subclass of: NTFS Link
subclass of: Symbolic Link
definition: NTFS junction points are are similar to NTFS symlinks but are defined only for directories. Only accepts local absolute paths.
alternative label: Junction Point

NTFS Link
type: Class
subclass of: File
subclass of: File System Link
definition: The NTFS filesystem defines various ways to link files, i.e. to make a file point to another file or its contents. The object being pointed to is called the target. There are three classes of NTFS links: (a) Hard links, which have files share the same MFT entry (inode), in the same filesystem; (b) Symbolic links, which record the path of another file that the links contents should show and can accept relative paths; and (c) Junction points, which are similar to symlinks but defined only for directories and only accepts local absolute paths

NTFS Symbolic Link
type: Class
subclass of: NTFS Link
subclass of: Symbolic Link
definition: An NTFS symbolic link records the path of another file that the links contents should show. Can accept relative paths. SMB networking (UNC path) and directory support added in NTFS 3.1.
alternative label: NTFS Symlink

NTP Broadcast Event
type: Class
subclass of: NTP Event
definition: An event where an NTP server broadcasts time synchronization messages to multiple clients simultaneously, enabling synchronization without individual request-response cycles.

NTP Client Synchronization Event
type: Class
subclass of: NTP Event
definition: An event where an NTP client requests and adjusts its clock based on time synchronization data provided by an NTP server, ensuring alignment with a standard time source.

NTP Control Message Event
type: Class
subclass of: NTP Event
definition: An event where an NTP client or server exchanges control messages used for diagnostic, monitoring, or administrative management of the NTP protocol, rather than time synchronization.

NTP Event
type: Class
subclass of: Application Layer Event
subclass of: UDP Event
subclass of: Restriction
  on property: has-participant
  some values from: Network Time Server
definition: An event involving the Network Time Protocol (NTP), a protocol designed to synchronize the clocks of computer systems over packet-switched, variable-latency data networks, UDP as its transport protocol.

NTP Server Response Event
type: Class
subclass of: NTP Event
definition: An event where an NTP server sends time synchronization data to a client, enabling the client to align its local clock with the server's reference time.

NTP Symmetric Active Exchange Event
type: Class
subclass of: NTP Event
definition: An event where an NTP peer operating in symmetric active mode initiates clock synchronization messages to a peer in symmetric passive mode, enabling time synchronization between equal-status systems.

NTP Symmetric Passive Exchange Event
type: Class
subclass of: NTP Event
definition: An event where an NTP peer operating in symmetric passive mode responds to clock synchronization messages initiated by a symmetric active peer, facilitating mutual timekeeping.

Naive Bayes Classifier
type: Class
subclass of: Classification
type: NamedIndividual
d3fend-id: D3A-NBC
definition: The Naïve Bayes classifier is a supervised machine learning algorithm, which is used for classification tasks, like text classification. It is also part of a family of generative learning algorithms, meaning that it seeks to model the distribution of inputs of a given class or category.
kb-article: ## References Naive Bayes. IBM. [Link](https://www.ibm.com/topics/naive-bayes?mhsrc=ibmsearch_a&mhq=naive%20bayes).

Named Pipe
type: Class
subclass of: Pipe
type: NamedIndividual
definition: In computing, a named pipe (also known as a FIFO for its behavior) is an extension to the traditional pipe concept on Unix and Unix-like systems, and is one of the methods of inter-process communication (IPC). The concept is also found in OS/2 and Microsoft Windows, although the semantics differ substantially. A traditional pipe is 'unnamed' and lasts only as long as the process. A named pipe, however, can last as long as the system is up, beyond the life of the process. It can be deleted if no longer used. Usually a named pipe appears as a file, and generally processes attach to it for IPC.

Network
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: A network is a group of computers that use a set of common communication protocols over digital interconnections for the purpose of sharing resources located on or provided by the network nodes. The interconnections between nodes are formed from a broad spectrum of telecommunication network technologies, based on physically wired, optical, and wireless radio-frequency methods that may be arranged in a variety of network topologies.
alternative label: Computer Network

Network Access Mediation
type: Class
subclass of: Access Mediation
subclass of: Restriction
  on property: isolates
  some values from: Network
type: NamedIndividual
isolates: Network
kb-reference: Reference-WhatIsNetworkAccessControl
d3fend-id: D3-NAM
definition: Network access mediation is the control method for authorizing access to a system by a user (or a process acting on behalf of a user) communicating through a network, including a local area network, a wide area network, and the Internet.
kb-article: ## How it works Network Access Mediation is a crucial process in telecommunications and IT networks that involves controlling access to network resources. It acts as an intermediary layer between network access requests and the actual network resources, ensuring that only authorized users and devices can access the network.
synonym: Network Access Control

Network Card Firmware
type: Class
subclass of: Peripheral Firmware
definition: Firmware that is installed on a network card (network interface controller).
alternative label: Network Controller Firmware

Network Connection Close Event
type: Class
subclass of: Network Connection Event
definition: An event where a network connection is closed.

Network Connection Event
type: Class
subclass of: Network Event
subclass of: Restriction
  on property: has-participant
  some values from: Network Session
definition: An event related to the establishment, maintenance, or termination of a network connection.

Network Connection Fail Event
type: Class
subclass of: Network Connection Event
definition: An event where a network connection attempt fails.

Network Connection Listen Event
type: Class
subclass of: Network Connection Event
definition: An event where a network endpoint begins listening for new network connections.

Network Connection Open Event
type: Class
subclass of: Network Connection Event
definition: An event where a network connection is successfully opened.

Network Connection Refuse Event
type: Class
subclass of: Network Connection Event
definition: An event where a network connection is refused.

Network Connection Reset Event
type: Class
subclass of: Network Connection Event
definition: An event where an attempt is made to establish a network connection.

Network Device Event
type: Class
subclass of: Hardware Device Event
definition: An event capturing the activity or state of network devices, such as Ethernet adapters, Wi-Fi modules, or virtual interfaces. These events highlight connectivity, configuration, or performance changes.

Network Directory Resource
type: Class
subclass of: Network File Share Resource
subclass of: Restriction
  on property: contains
  some values from: Directory
type: NamedIndividual
contains: Directory
definition: A directory resource made available from one host to other hosts on a computer network.

Network Event
type: Class
subclass of: Digital Event
subclass of: Restriction
  on property: has-participant
  some values from: Network Traffic
definition: An event involving network communications within or between digital systems.

Network File Resource
type: Class
subclass of: Network File Share Resource
subclass of: Restriction
  on property: contains
  some values from: File
type: NamedIndividual
contains: File
definition: A computer file resource made available from one host to other hosts on a computer network.

Network File Share Resource
type: Class
subclass of: Network Resource
type: NamedIndividual
definition: A shared file resource, or network file share, is a computer file made available from one host to other hosts on a computer network. Network sharing is made possible by inter-process communication over the network. It includes both files and directories.

Network Flow
type: Class
subclass of: Digital Information
subclass of: Restriction
  on property: summarizes
  some values from: Network Traffic
type: NamedIndividual
summarizes: Network Traffic
definition: A summarization of network transactions between a client and server. It often summarizes bytes sent, bytes received, and protocol flags.

Network Flow Sensor
type: Class
subclass of: Network Sensor
subclass of: Restriction
  on property: monitors
  some values from: Network Flow
type: NamedIndividual
monitors: Network Flow
definition: Monitors network traffic and produces summaries of data flows traversing the network.

Network Init Script File Resource
type: Class
subclass of: Init Script
subclass of: Network File Resource
type: NamedIndividual
definition: A computer file resource made available from one host to other hosts on a computer network that is also an initialization script.

Network Interface Card
type: Class
subclass of: Hardware Device
type: NamedIndividual
definition: A network interface card (NIC, also known as a network interface controller, network adapter, LAN adapter or physical network interface, and by similar terms) is a computer hardware component that connects a computer to a computer network.
synonym: Network Interface Controller

Network Isolation
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Isolate
type: NamedIndividual
enables: Isolate
d3fend-id: D3-NI
definition: Network Isolation techniques prevent network hosts from accessing non-essential system network resources.

Network Link
type: Class
subclass of: Logical Link
definition: A network link is a link within the network layer, which is responsible for packet forwarding including routing through intermediate routers.
synonym: Layer-3 Link
synonym: Network Layer Link

Network Mapping
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Model
type: NamedIndividual
enables: Model
d3fend-id: D3-NM
definition: Network mapping encompasses the techniques to identify and model the physical layer, network layer, and data exchange layers of the organization's network and their physical location, and determine allowed pathways through that network.
display-order: 3

Network Node
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: In telecommunications networks, a node (Latin nodus, 'knot') is either a redistribution point or a communication endpoint. The definition of a node depends on the network and protocol layer referred to. A physical network node is an electronic device that is attached to a network, and is capable of creating, receiving, or transmitting information over a communications channel. A passive distribution point such as a distribution frame or patch panel is consequently not a node.

Network Node Inventory
type: Class
subclass of: Asset Inventory
subclass of: Restriction
  on property: inventories
  some values from: Network Node
type: NamedIndividual
inventories: Network Node
kb-reference: Reference-IEEE-802 1AB-2016
kb-reference: Reference-QualysNetworkPassiveSensorGettingStartedGuide
kb-reference: Reference-RFC3411-AnArchitectureForDescribingSimpleNetworkManagementProtocolSNMPManagementFrameworks
kb-reference: Reference-Web-BasedEnterpriseManagement
kb-reference: Reference-Windows-Management-Infrastructure
kb-reference: Reference-Windows-Management-Instrumentation
d3fend-id: D3-NNI
definition: Network node inventorying identifies and records all the network nodes (hosts, routers, switches, firewalls, etc.) in the organization's architecture.
kb-article: ## How it works Administrators collect information on network nodes in their architecture using a variety of administrative and management tools that query network devices and nodes for information. In some cases, where such queries are not supported or provide specific information of interest, an administrator may also collect this information through network enumeration methods to include host discovery and scanning for active ports and services. ## Considerations * Scanning and probing techniques using mapping tools can result in side effects to information technology (IT) and operational technology (OT) systems. * An adversary conducting network enumeration may engage in activities that parallel normal network node inventorying activities, but would require escalating to admin privileges for most of the operations requiting administrative tools ## Examples * Link-layer discovery * Link-layer Discovery Protocol (LLDP) * Cisco Discovery Protocol (CDP) * Application-layer discovery * Simple Network Management Protocol (SNMP) collects MIB information * Web-based Enterprise Management (WBEM) collects CIM information * Windows Management Instrumentation (WMI) * Windows Management Infrastructure (MI)
synonym: System Discovery
synonym: System Inventorying

Network Packet
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: A network packet is a formatted unit of data carried by a packet-switched network. Computer communications links that do not support packets, such as traditional point-to-point telecommunications links, simply transmit data as a bit stream. When data is formatted into packets, packet switching is possible and the bandwidth of the communication medium can be better shared among users than with circuit switching.

Network Printer
type: Class
subclass of: Shared Computer
definition: In computing, a network printer is a device that can be accessed over a network which makes a persistent representation of graphics or text, usually on paper. While most output is human-readable, bar code printers are an example of an expanded use for printers. The different types of printers include 3D printer, inkjet printer, laser printer, thermal printer, etc. Note that not all printers are networked and the digital information to be printed must be passed either by removable media or as directly connecting the printer to a computer (e.g., by USB.)

Network Protocol Analyzer
type: Class
subclass of: Network Sensor
subclass of: Restriction
  on property: monitors
  some values from: Network Traffic
type: NamedIndividual
monitors: Network Traffic
definition: Monitors and parses network protocols to extract values from various network protocol layers.

Network Resource
type: Class
subclass of: Remote Resource
type: NamedIndividual
definition: In computing, a shared resource, or network share, is a computer resource made available from one host to other hosts on a computer network. It is a device or piece of information on a computer that can be remotely accessed from another computer, typically via a local area network or an enterprise intranet, transparently as if it were a resource in the local machine.Network sharing is made possible by inter-process communication over the network.
alternative label: Shared Resource

Network Resource Access
type: Class
subclass of: Resource Access
subclass of: Restriction
  on property: accesses
  some values from: Network Resource
subclass of: Restriction
  on property: accesses
  some values from: Resource
type: NamedIndividual
accesses: Network Resource
accesses: Resource
definition: Ephemeral digital artifact comprising a request of a network resource and any response from that network resource.

Network Resource Access Mediation
type: Class
subclass of: Access Mediation
subclass of: Restriction
  on property: isolates
  some values from: Network Resource
type: NamedIndividual
isolates: Network Resource
kb-reference: Reference-NIST-Special-Publication-800-53-Revision-5
d3fend-id: D3-NRAM
definition: Control of access to organizational systems and services by users or processes over a network.
kb-article: ## How it works Network Resource Access Control involves managing and regulating access to resources within an organization's network. This includes ensuring that only authorized users or processes can access specific systems or data, often through authentication and authorization mechanisms. Examples include accessing internal databases, file servers, or application services.
synonym: Remote Access Control

Network Scanner
type: Class
subclass of: Cyber Sensor
subclass of: Restriction
  on property: monitors
  some values from: Network
type: NamedIndividual
monitors: Network
definition: A network scanner is a computer program used to retrieve usernames and info on groups, shares, and services of networked computers. This type of program scans networks for vulnerabilities in the security of that network. If there is a vulnerability with the security of the network, it will send a report back to a hacker who may use this info to exploit that network glitch to gain entry to the network or for other malicious activities. Ethical hackers often also use the information to remove the glitches and strengthen their network.
alternative label: Network Enumerator

Network Sensor
type: Class
subclass of: Cyber Sensor

Network Service
type: Class
subclass of: Service Application Process
definition: In computer networking, a network service is an application running at the network application layer and above, that provides data storage, manipulation, presentation, communication or other capability which is often implemented using a client-server or peer-to-peer architecture based on application layer network protocols. Clients and servers will often have a user interface, and sometimes other hardware associated with it.

Network Session
type: Class
subclass of: Session
subclass of: Restriction
  on property: produces
  some values from: Network Traffic
type: NamedIndividual
produces: Network Traffic
definition: A network session is a temporary and interactive information interchange between two or more devices communicating over a network. A session is established at a certain point in time, and then 'torn down' - brought to an end - at some later point. An established communication session may involve more than one message in each direction. A session is typically stateful, meaning that at least one of the communicating parties needs to hold current state information and save information about the session history in order to be able to communicate, as opposed to stateless communication, where the communication consists of independent requests with responses. Network sessions may be established and implemented as part of protocols and services at the application, session, or transport layers of the OSI model.

Network Time Server
type: Class
subclass of: Server
definition: A network time server is a server computer that reads the actual time from a reference clock and distributes this information to its clients using a computer network. The time server may be a local network time server or an internet time server. The time server may also be a stand-alone hardware device. It can use NTP (RFC5905) or other protocols.

Network Traffic
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: contains
  some values from: Network Packet
subclass of: Restriction
  on property: may-contain
  some values from: Domain Name
subclass of: Restriction
  on property: originates-from
  some values from: Physical Location
type: NamedIndividual
contains: Network Packet
may-contain: Domain Name
originates-from: Physical Location
definition: Network traffic or data traffic is the data, or alternatively the amount of data, moving across a network at a given point of time. Network data in computer networks is mostly encapsulated in network packets, which provide the load in the network.
alternative label: Data Traffic

Network Traffic Analysis
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Detect
type: NamedIndividual
enables: Detect
d3fend-id: D3-NTA
definition: Analyzing intercepted or summarized computer network traffic to detect unauthorized activity.

Network Traffic Analysis Software
type: Class
subclass of: Developer Application
type: NamedIndividual
type: Digital Artifact
definition: A packet analyzer, also known as packet sniffer, protocol analyzer, or network analyzer, is a computer program or computer hardware such as a packet capture appliance, that can intercept and log traffic that passes over a computer network or part of a network.
alternative label: Network Sniffer

Network Traffic Community Deviation
type: Class
subclass of: Network Traffic Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Network Traffic
type: NamedIndividual
analyzes: Network Traffic
kb-reference: Reference-SystemForImplementingThreatDetectionUsingDailyNetworkTrafficCommunityOutliers VECTRANETWORKSInc
d3fend-id: D3-NTCD
definition: Establishing baseline communities of network hosts and identifying statistically divergent inter-community communication.
kb-article: ## How it works Hosts/users within a computer network are analyzed to identify communities of hosts which frequently communicate. Future communications between communities that don't usually communicate can then be detected. For example, if a community of hosts that communicate in support of a company's finance division suddenly starts to access the code server usually accessed only by engineers, this may indicate unauthorized activity. ## Considerations * Potential for false positives in very dynamic network environments. * Attackers that move low and slow may not differentiate their behavior enough to trigger an alert.

Network Traffic Filtering
type: Class
subclass of: Network Isolation
subclass of: Restriction
  on property: filters
  some values from: Network Traffic
type: NamedIndividual
filters: Network Traffic
kb-reference: Reference-ActiveFirewallSystemAndMethodology McAfeeLLC
kb-reference: Reference-AutomaticallyGeneratingRulesForConnectionSecurity Microsoft
kb-reference: Reference-FWTK-FirewallToolkit
kb-reference: Reference-FirewallForInterentAccess SecureComputingLLC
kb-reference: Reference-FirewallForProcessingAConnectionlessNetworkPacket NationalSecurityAgency
kb-reference: Reference-FirewallForProcessingConnection-orientedAndConnectionlessDatagramsOverAConnection-orientedNetwork NationalSecurityAgency
kb-reference: Reference-FirewallsThatFilterBasedUponProtocolCommands IntelCorp
kb-reference: Reference-MethodForControllingComputerNetworkSecurity CheckpointSoftwareTechnologiesLtd
kb-reference: Reference-NetworkFirewallWithProxy SecureComputingLLC
d3fend-id: D3-NTF
definition: Restricting network traffic originating from any location.

Network Traffic Policy Mapping
type: Class
subclass of: Network Mapping
subclass of: Restriction
  on property: maps
  some values from: Access Control Configuration
subclass of: Restriction
  on property: queries
  some values from: Network Agent
type: NamedIndividual
maps: Access Control Configuration
queries: Network Agent
d3fend-id: D3-NTPM
definition: Network traffic policy mapping identifies and models the allowed pathways of data at the network, tranport, and/or application levels.
synonym: DLP Policy Mapping
synonym: Firewall Mapping
synonym: IPS Policy Mapping
synonym: Web Security Gateway Policy Mapping

Network Traffic Signature Analysis
type: Class
subclass of: Network Traffic Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Network Traffic
type: NamedIndividual
analyzes: Network Traffic
d3fend-id: D3-NTSA
definition: Analyzing network traffic and compares it to known signatures
kb-article: ## How it works Network signature analysis relies on predefined patterns, or signatures, to identify malicious network activity. These signatures typically match against specific byte sequences, packet header information, or protocol anomalies indicative of known threats. The process works as follows: * Packet Capture: Network traffic is captured on an interface or port, resulting in a stream of raw packets. * Preprocessing: The captured packets are preprocessed, cleaning and normalizing the data for efficient analysis. * Signature Matching: Each packet is compared against a database of signatures using dedicated engines. ## Considerations ### False Negatives Network signature analysis is susceptible to generating false negatives. These occur when malicious activity evades detection due to limitations in the signature-based approach. Here are some common causes: * Evolving threats: Attackers frequently modify their tactics, rendering existing signatures ineffective against new variants. * Obfuscation: Attackers may disguise malicious content using encryption, encoding, or other techniques to bypass signature detection. * Limited visibility: Signatures rely on specific patterns. If crucial information is encrypted or hidden, the signature might miss the threat. * Zero-day attacks: By definition, new and unknown attacks lack corresponding signatures, allowing them to pass undetected. ### False Positives Network signature analysis is susceptible to generating false positives. These occur when the signature analysis triggers an alert for benign traffic. Common causes include: * Overly broad signatures: Rules designed to be too general might match harmless activities, generating false alarms. * Network misconfigurations: Improperly configured devices or legitimate network activity can mimic malicious patterns, triggering false positives. * Data errors: Corrupted or incomplete network data can lead to misinterpretations and false alerts.

Network Vulnerability Assessment
type: Class
subclass of: Network Mapping
subclass of: Restriction
  on property: evaluates
  some values from: Network
subclass of: Restriction
  on property: identifies
  some values from: Vulnerability
type: NamedIndividual
evaluates: Network
identifies: Vulnerability
d3fend-id: D3-NVA
definition: Network vulnerability assessment relates all the vulnerabilities of a network's components in the context of their configuration and interdependencies and can also include assessing risk emerging from the network's design as a whole, not just the sum of individual network node or network segment vulnerabilities.

Non-Parametric Tests
type: Class
subclass of: Hypothesis Testing
type: NamedIndividual
d3fend-id: D3A-NPT
definition: A non-parametric test relies is used when the underlying distribution of data is non-symmetric (non-normal distribution).
kb-article: ## References Newcastle University. (n.d.). Parametric Hypothesis Tests. [Link](https://www.ncl.ac.uk/webtemplate/ask-assets/external/maths-resources/psychology/non-parametric-hypothesis-tests.html)

Non-Person Entity
type: Class
subclass of: Agent
definition: An entity related to information technology with a digital identity that acts in cyberspace, but is not a human actor. This can include organizations, hardware objects (physical entities/devices), software objects (virtual/logical entities), and information artifacts.
synonym: NPE

Non-monotonic Logic
type: Class
subclass of: Symbolic AI
type: NamedIndividual
d3fend-id: D3A-NML
definition: Non-monotonic logic is a formal logic whose conclusion relation is not monotonic. In other words, non-monotonic logics are devised to capture and represent defeasible inferences (cf. defeasible reasoning), i.e., a kind of inference in which reasoners draw tentative conclusions, enabling reasoners to retract their conclusion(s) based on further evidence.
kb-article: ## References 1. Non-monotonic logic. (2023, June 1). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Non-monotonic_logic)

Nonlinear Regression
type: Class
subclass of: Regression Analysis
type: NamedIndividual
d3fend-id: D3A-NR
definition: Nonlinear regression is a form of regression analysis in which observational data are modeled by a function which is a nonlinear combination of the model parameters and depends on one or more independent variables.
kb-article: ## References Wikipedia. (n.d.). Nonlinear regression. [Link](https://en.wikipedia.org/wiki/Nonlinear_regression)

Nonlinear Regression Learning
type: Class
subclass of: Regression Analysis Learning
type: NamedIndividual
d3fend-id: D3A-NRL
definition: A supervised learning method that builds a non-linear regression model using training data.
kb-article: ## References Wikipedia. (n.d.). Nonlinear regression. [Link](https://en.wikipedia.org/wiki/Nonlinear_regression)

Null Pointer Checking
type: Class
subclass of: Pointer Validation
subclass of: Restriction
  on property: hardens
  some values from: Memory Free Function
subclass of: Restriction
  on property: hardens
  some values from: Pointer Dereferencing Function
type: NamedIndividual
hardens: Memory Free Function
hardens: Pointer Dereferencing Function
kb-reference: Reference-NullPointerChecking SEI
kb-reference: Reference-NullPointerDereference CWE
kb-reference: Reference-PointerValidationFunction SEI
d3fend-id: D3-NPC
definition: Checking if a pointer is NULL.
kb-article: ## How it Works Programmatically checking if a pointer is NULL before use. ## Considerations * Pointers should be checked prior to use after they have, or may have been modified. * Note that it may vary by circumstance whether the caller, or callee is responsible for checking if a pointer is NULL. * Note: This resource should not be considered a definitive or exhaustive coding guideline.
synonym: Nil Pointer Checking

Numeric Pattern Matching
type: Class
subclass of: Pattern Matching
type: NamedIndividual
d3fend-id: D3A-NPM
definition: Numeric pattern matching uses a pattern specification and sees if the numeric value matches that pattern--simple forms include exact matching and range matching.

OS API Access Process
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Access Process
type: NamedIndividual
invokes: Access Process

OS API Allocate Memory
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Allocate Memory
type: NamedIndividual
invokes: Allocate Memory

OS API Connect Socket
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Connect Socket
type: NamedIndividual
invokes: Connect Socket

OS API Copy Token
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Copy Token
type: NamedIndividual
invokes: Copy Token

OS API Create File
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Create File
type: NamedIndividual
invokes: Create File

OS API Create Process
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Create Process
type: NamedIndividual
invokes: Create Process

OS API Create Socket
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Create Socket
type: NamedIndividual
invokes: Create Socket

OS API Create Thread
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Create Thread
type: NamedIndividual
invokes: Create Thread

OS API Delete File
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Delete File
type: NamedIndividual
invokes: Delete File

OS API Exec
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Exec
type: NamedIndividual
invokes: Exec

OS API Free Memory
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Free Memory
type: NamedIndividual
invokes: Free Memory

OS API Function
type: Class
subclass of: Software

OS API Get System Time
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Get System Time
type: NamedIndividual
invokes: Get System Time

OS API Get Thread Context
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Get Thread Context
type: NamedIndividual
invokes: Get Thread Context

OS API Load Module
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Load Module
type: NamedIndividual
invokes: Load Module

OS API Move File
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Move File
type: NamedIndividual
invokes: Move File

OS API Open File
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Open File
type: NamedIndividual
invokes: Open File

OS API Read File
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Read File
type: NamedIndividual
invokes: Read File

OS API Read Memory
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Read Memory
type: NamedIndividual
invokes: Read Memory

OS API Resume Process
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Resume Process
type: NamedIndividual
invokes: Resume Process

OS API Resume Thread
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Resume Thread
type: NamedIndividual
invokes: Resume Thread

OS API Save Registers
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Save Registers
type: NamedIndividual
invokes: Save Registers

OS API Set Registers
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Set Registers
type: NamedIndividual
invokes: Set Registers

OS API Set Thread Context
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Set Thread Context
type: NamedIndividual
invokes: Set Thread Context

OS API Suspend Process
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Suspend Process
type: NamedIndividual
invokes: Suspend Process

OS API Suspend Thread
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Suspend Thread
type: NamedIndividual
invokes: Suspend Thread

OS API System Function
type: Class
subclass of: OS API Function
definition: Indirect System calls are made through an OS-specific library (like glibc in Linux) that provides a higher-level API for the system calls.
synonym: Indirect System Call

OS API Terminate Process
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Terminate Process
type: NamedIndividual
invokes: Terminate Process

OS API Trace Process
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Trace Process
type: NamedIndividual
invokes: Trace Process

OS API Trace Thread
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Trace Thread
type: NamedIndividual
invokes: Trace Thread

OS API Unload Module
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Unload Module
type: NamedIndividual
invokes: Unload Module

OS API Write File
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Write File
type: NamedIndividual
invokes: Write File

OS API Write Memory
type: Class
subclass of: OS API System Function
subclass of: Restriction
  on property: invokes
  some values from: Write Memory
type: NamedIndividual
invokes: Write Memory

OT Actuator
type: Class
subclass of: Actuator
type: NamedIndividual
definition: An OT actuator is an industrial-grade actuator optimized for operational technology (OT) environments, such as SCADA or process-control systems. It tolerates harsher conditions, meets stricter safety and reliability standards, and integrates seamlessly with ICS protocols to enable real-time mechanical motion or adjustments in production lines and critical infrastructure.

OT Controller
type: Class
subclass of: OT Embedded Computer
subclass of: Restriction
  on property: communicates-with
  some values from: OT I/O Module
subclass of: Restriction
  on property: controls
  some values from: OT Actuator
subclass of: Restriction
  on property: monitors
  some values from: OT Sensor
subclass of: Restriction
  on property: powered-by
  some values from: OT Power Supply
type: NamedIndividual
communicates-with: OT I/O Module
controls: OT Actuator
monitors: OT Sensor
powered-by: OT Power Supply
definition: An OT Controller is an industrial control device that automatically regulates one or more controlled variables in response to command inputs and real-time feedback signals.

OT Embedded Computer
type: Class
subclass of: Embedded Computer
definition: A ruggedized computational device, embedded in industrial control systems, designed to handle real-time tasks and environmental stressors common in OT.

OT I/O Module
type: Class
subclass of: I/O Module
subclass of: Restriction
  on property: communicates-with
  some values from: OT Actuator
subclass of: Restriction
  on property: communicates-with
  some values from: OT Sensor
type: NamedIndividual
communicates-with: OT Actuator
communicates-with: OT Sensor
definition: An OT I/O Module is an industrial-grade interface designed for harsh Operational Technology (OT) environments. It reliably connects sensors and actuators to industrial control systems, ensuring precise, real-time data exchange in applications such as SCADA or ICS. Engineered for ruggedness and consistent performance, it can manage analog, digital, or other specialized signal types while enduring demanding conditions.
comment: There are many types of I/O modules, including: analog input, analog output, HART input, HART output, digital input, digital output, mV input, pulse input, universal I/O, vibration input, and many other types of input or output modules. The functionality of the I/O Module can be embedded in the controller or as a separate module connected via chassis or I/O link.
example: Rockwell Compact 5000 IO Module

OT Power Supply
type: Class
subclass of: Power Supply
type: NamedIndividual
definition: An OT power supply is a power supply whose control amplifier is optimized for signal-processing tasks rather than supplying mere steady-state power to a load. It is a self-contained combination of operational amplifiers, power amplifiers, and integral power circuits designed for higher-level operations in industrial or OT contexts.
example: Phoenix Contact QUINT, Eaton PSG, and many controller-branded power supplies.

OT Sensor
type: Class
subclass of: Sensor
type: NamedIndividual
definition: An OT Sensor is an industrial-grade sensing device engineered for operational technology (OT) environments (e.g. SCADA, ICS). It measures physical variables—such as pressure, temperature, or flow—under demanding conditions, converting them into reliable signals for real-time monitoring and process control loops.
comment: Components of the sensor include a sensing element and may include a power source, display, housing, communication interface or signal processor.
example: Level sensors, pressure sensors, temperature sensors, and flow measurement devices.

OWL
type: Class
subclass of: Description Logic
type: NamedIndividual
d3fend-id: D3A-OWL
definition: The Web Ontology Language (OWL) is a family of knowledge representation languages for authoring ontologies.
kb-article: ## How it works Ontologies are a formal way to describe taxonomies and classification networks, essentially defining the structure of knowledge for various domains: the nouns representing classes of objects and the verbs representing relations between the objects. The OWL languages are characterized by formal semantics. They are built upon the World Wide Web Consortium's (W3C) standard for objects called the Resource Description Framework (RDF). OWL classes correspond to description logic (DL) _concepts_. OWL properties to DL _roles_, and individuals are named the same way in OWL and other DLs. ## References 1. Web Ontology Language. (2023, April 23). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Web_Ontology_Language)
synonym: Web Ontology Language

Object Eviction
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Evict
type: NamedIndividual
enables: Evict
d3fend-id: D3-OE
definition: Terminate or remove an object from a host machine. This is the broadest class for object eviction.

Object File
type: Class
subclass of: File
type: NamedIndividual
definition: An object file is a file that contains relocatable machine code.

Offensive Action
type: Class
subclass of: Cyber Action

Offensive Tactic
type: Class
subclass of: Goal
subclass of: Restriction
  on property: enabled-by
  some values from: Offensive Technique
definition: Per ATT&CK, these are defined as Tactical Goals, not Tactics per se. Many children also fit definition of tactics. Some are neither tactics or tactical goals really (e.g., Execution, which is a useful grouping, but an action, not really a tactic or technique.
synonym: Tactical Objective

Offensive Technique
type: Class
subclass of: Cyber Technique
subclass of: Restriction
  on property: enables
  some values from: Offensive Tactic
subclass of: Restriction
  on property: initiates
  some values from: Access
display-baseurl: /offensive-technique/attack/

Office Application
type: Class
subclass of: User Application
type: NamedIndividual
definition: An office application is one that is part of an application suite (e.g., Microsoft Office, Open Office).

Office Application File
type: Class
subclass of: Document File
type: NamedIndividual
definition: A document file in a format associated with an d3f:OfficeApplication.

One-time Password
type: Class
subclass of: Password Rotation
subclass of: Restriction
  on property: use-limits
  some values from: Password
type: NamedIndividual
kb-reference: Reference-DigitalIdentityGuidelines800-63-3
kb-reference: Reference-RFC2289-AOne-TimePasswordSystem
use-limits: Password
d3fend-id: D3-OTP
definition: A one-time password is valid for only one user authentication.
kb-article: ## How it works When a user initiates authentication, they are asked for a one-time password, often in addition to other credentials such as a traditional password or smart card. The one-time password may be from a list provided in advance, sent via a channel such as SMS or HTTPS to an app, or a generated token. In the case of a physical token which generates one-time passwords incrementally based on time elapsed, that token device need not be connected to the internet. In different implementations, an administrator of the system, or a user with additional verification, can adjust for clock skew between the token and the verification system as needed. ## Considerations ### Compromise of delivery channel - SIM Swapping - Secure token visual compromise - Insecure delivery channel ### Compromise of delivery device Physical loss of One-time Password device. ### Compromise of long-term backup codes These are often provided in the form of a downloadable document with a regular name, which can be searched for in the case that the user forgets where they put them. This digital file or printed document could be stolen. Additionally, after the code file is printed, it could be recovered from the system printer spool unless the spooler cache is cleared.
synonym: OTP

Open-source Developer
type: Class
subclass of: Product Developer

Open File
type: Class
subclass of: System Call
subclass of: Restriction
  on property: accesses
  some values from: File
type: NamedIndividual
accesses: File
definition: For most file systems, a program initializes access to a file in a file system using the open system call. This allocates resources associated to the file (the file descriptor), and returns a handle that the process will use to refer to that file. In some cases the open is performed by the first access. During the open, the filesystem may allocate memory for buffers, or it may wait until the first operation. Various other errors which may occur during the open include directory update failures, un-permitted multiple connections, media failures, communication link failures and device failures.

Operating System
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: contains
  some values from: Kernel
subclass of: Restriction
  on property: contains
  some values from: System Service Software
subclass of: Restriction
  on property: may-contain
  some values from: Operating System Configuration Component
type: NamedIndividual
contains: Kernel
contains: System Service Software
may-contain: Operating System Configuration Component
definition: An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs. All computer programs, excluding firmware, require an operating system to function. Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and other resources.

Operating System Configuration
type: Class
subclass of: Configuration Resource
type: NamedIndividual
definition: Information used to configure the services, parameters, and initial settings for an operating system.

Operating System Configuration Component
type: Class
subclass of: Operating System Configuration
type: NamedIndividual
definition: An component of the overall information necessary for the configuration of an operating system.
alternative label: Operating System Configuration Information
alternative label: System Configuration

Operating System Configuration File
type: Class
subclass of: Configuration File
subclass of: Operating System File
type: NamedIndividual
definition: An operating system configuration file is a file used to configure the operating system.
alternative label: System Configuration File

Operating System Executable File
type: Class
subclass of: Operating System File
type: NamedIndividual
definition: An operating system executable is a critical executable that is part of the operating system, and without which, the operating system may not operate correctly.

Operating System File
type: Class
subclass of: File
type: NamedIndividual
definition: An operating system file is a file that is part of, or used to store information about, the operating system itself.

Operating System Log File
type: Class
subclass of: Log File
subclass of: Operating System File
type: NamedIndividual
definition: An operating system log file records events that occur in an operating system

Operating System Monitoring
type: Class
subclass of: Platform Monitoring
type: NamedIndividual
enables: Detect
kb-reference: Reference-HostIntrusionPreventionSystemUsingSoftwareAndUserBehaviorAnalysis SophosLtd
kb-reference: Reference-UserActivityFromClearingEventLogs MITRE
d3fend-id: D3-OSM
definition: The operating system software, for D3FEND's purposes, includes the kernel and its process management functions, hardware drivers, initialization or boot logic. It also includes and other key system daemons and their configuration. The monitoring or analysis of these components for unauthorized activity constitute **Operating System Monitoring**.
kb-article: ## Technique Overview "An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs." [1] Operating System Monitoring Techniques have varied implementations including built-in kernel modules, third-party privileged system daemons, or even standard systems administration tools included with an operating system. 1. http://dbpedia.org/resource/Operating_system

Operating System Packaging Tool
type: Class
subclass of: Software Packaging Tool
definition: A software packaging tool oriented on building a software package for a particular operating system (e.g. rpmbuild.)

Operating System Process
type: Class
subclass of: Process
type: NamedIndividual
definition: An operating system process, or system process, is a process running to perform operating system functions.
alternative label: System Process

Operating System Shared Library File
type: Class
subclass of: Operating System File
subclass of: Shared Library File
type: NamedIndividual
definition: An operating system shared library file is a shared library file that is part of the operating system and that incorporates common operating system code for use by any application or to provide operating system services.

Operational Activity Mapping
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Model
type: NamedIndividual
enables: Model
kb-reference: Reference-CatiaUAFPlugin
d3fend-id: D3-OAM
definition: Operational activity mapping identifies activities of the organization and the organization's suborganizations, groups, roles, and individuals that carry out the activities and then establishes the dependencies of the activities on the systems and people that perform those activities.
synonym: Mission Mapping

Operational Dependency Mapping
type: Class
subclass of: Operational Activity Mapping
subclass of: Restriction
  on property: maps
  some values from: Dependency
subclass of: Restriction
  on property: maps
  some values from: Organizational Activity
type: NamedIndividual
kb-reference: Reference-CatiaUAFPlugin
kb-reference: Reference-CyberCommandSystemCYCS
kb-reference: Reference-DaggerFactSheet
kb-reference: Reference-DaggerModelingAndVisualizationForMissionImpactSituationalAwareness
kb-reference: Reference-MissionDependencyModelingForCyberSituationalAwareness
kb-reference: Reference-UnifiedArchitectureFrameworkUAF
maps: Dependency
maps: Organizational Activity
d3fend-id: D3-ODM
definition: Operational dependency mapping identifies and models the dependencies of the organization's activities on each other and on the organization's performers (people, systems, and services.) This may include modeling the higher- and lower-level activities of an organization forming a hierarchy, or layering, of the dependencies in an organization's activities.

Operational Risk Assessment
type: Class
subclass of: Operational Activity Mapping
subclass of: Restriction
  on property: evaluates
  some values from: Organization
subclass of: Restriction
  on property: identifies
  some values from: Vulnerability
type: NamedIndividual
evaluates: Organization
identifies: Vulnerability
kb-reference: Reference-NIST-RMF-Quick-Start-Guide-Assess-Step-FAQ
kb-reference: Reference-NIST-Special-Publication-800-160-Volume-1
kb-reference: Reference-NIST-Special-Publication-800-37-Revision-2
kb-reference: Reference-NIST-Special-Publication-800-53A-Revision-5
kb-reference: Reference-NISTIR-8011-Volume-1
d3fend-id: D3-ORA
definition: Operational risk assessment identifies and models the vulnerabilities of, and risks to, an organization's activities individually and as a whole.
synonym: Mission Risk Assessment

Operations Center Computer
type: Class
subclass of: Shared Computer
definition: Mainframe computers or mainframes (colloquially referred to as "big iron") are computers used primarily by large organizations for critical applications; bulk data processing, such as census, industry and consumer statistics, and enterprise resource planning; and transaction processing. They are larger and have more processing power than some other classes of computers: minicomputers, servers, workstations, and personal computers.
alternative label: Mainframe

Optical Disc Image
type: Class
subclass of: Disk Image
definition: An optical disc image (or ISO image, from the ISO 9660 file system used with CD-ROM media) is a disk image that contains everything that would be written to an optical disc, disk sector by disc sector, including the optical disc file system.

Optical Modem
type: Class
subclass of: Modem
definition: A modem that connects to a fiber optic network is known as an optical network terminal (ONT) or optical network unit (ONU). These are commonly used in fiber to the home installations, installed inside or outside a house to convert the optical medium to a copper Ethernet interface, after which a router or gateway is often installed to perform authentication, routing, NAT, and other typical consumer internet functions, in addition to "triple play" features such as telephony and television service.

Orchestration Controller
type: Class
subclass of: Orchestration Server
subclass of: Restriction
  on property: contains
  some values from: Container Orchestration Software
type: NamedIndividual
contains: Container Orchestration Software
definition: An orchestration server provides orchestration services that automate the configuration, coordination, and management of computer systems and software.

Orchestration Server
type: Class
subclass of: Server
definition: A d3f:Server which is involved with the orchestration of workloads or the execution of orchestrated workloads.

Orchestration Worker
type: Class
subclass of: Orchestration Server
definition: A d3f:Server which receives commands from a d3f:OrchestrationController to execute workloads.

Organization
type: Class
subclass of: Agent Group
subclass of: Non-Person Entity
subclass of: Restriction
  on property: has-member
  some values from: Person
type: NamedIndividual

Organization Mapping
type: Class
subclass of: Operational Activity Mapping
subclass of: Restriction
  on property: maps
  some values from: Dependency
subclass of: Restriction
  on property: maps
  some values from: Organization
subclass of: Restriction
  on property: maps
  some values from: Person
subclass of: Restriction
  on property: may-map
  some values from: Organizational Activity
type: NamedIndividual
kb-reference: Reference-CatiaUAFPlugin
kb-reference: Reference-OrganizationalManagementInSAPERPHCM
kb-reference: Reference-UnifiedArchitectureFrameworkUAF
maps: Dependency
maps: Organization
maps: Person
may-map: Organizational Activity
d3fend-id: D3-OM
definition: Organization mapping identifies and models the people, roles, and groups with an organization and the relations between them.
display-order: 4

Organizational Activity
type: Class
subclass of: Plan
type: NamedIndividual
definition: An activity is a specific behavior representing a set of actions that may be accomplished by an agent.
synonym: Business Process
synonym: Mission Function
see also: Mission Critical Function

Outbound Internet DNS Lookup Traffic
type: Class
subclass of: DNS Network Traffic
subclass of: Outbound Internet Network Traffic
subclass of: Outbound Network Traffic
subclass of: Restriction
  on property: may-contain
  some values from: DNS Lookup
type: NamedIndividual
may-contain: DNS Lookup
definition: Outbound internet DNS lookup traffic is network traffic using the DNS protocol on an outgoing connection initiated from a host within a network to a host outside the network.

Outbound Internet Encrypted Remote Terminal Traffic
type: Class
subclass of: Outbound Internet Encrypted Traffic
type: NamedIndividual
definition: Outbound internet encrypted remote terminal traffic is encrypted network traffic for a standard remote terminal protocol on an outgoing connection initiated from a host within a network to a host outside the network.
alternative label: Outbound Internet Encrypted RDP Traffic
alternative label: Outbound Internet Encrypted SSH Traffic

Outbound Internet Encrypted Traffic
type: Class
subclass of: Outbound Internet Network Traffic
type: NamedIndividual
definition: Outbound internet encrypted traffic is encrypted network traffic on an outgoing connection initiated from a host within a network to a host outside the network.

Outbound Internet Encrypted Web Traffic
type: Class
subclass of: Outbound Internet Encrypted Traffic
subclass of: Outbound Internet Web Traffic
type: NamedIndividual
definition: Outbound internet encrypted web traffic is network traffic using a standard web protocol on an outgoing connection initiated from a host within a network to a host outside the network.

Outbound Internet File Transfer Traffic
type: Class
subclass of: File Transfer Network Traffic
subclass of: Outbound Internet Network Traffic
subclass of: Outbound Network Traffic
subclass of: Restriction
  on property: contains
  some values from: File
type: NamedIndividual
contains: File
definition: Outbound internet file transfer traffic is file transfer traffic that is: (a) on an outgoing connection initiated from a host within a network to a host outside the network, and (b) using a standard file transfer protocol.

Outbound Internet Mail Traffic
type: Class
subclass of: Outbound Internet Network Traffic
type: NamedIndividual
definition: Outbound internet DNS lookup traffic is network traffic using a standard email protocol on an outgoing connection initiated from a host within a network to a host outside the network.
alternative label: Outbound Internet Email Traffic

Outbound Internet Network Traffic
type: Class
subclass of: Internet Network Traffic
subclass of: Outbound Network Traffic
type: NamedIndividual
definition: Outbound internet network traffic is network traffic on an outgoing connection initiated from a host within a network to a host outside the network.

Outbound Internet RPC Traffic
type: Class
subclass of: Outbound Internet Network Traffic
subclass of: Outbound Network Traffic
subclass of: RPC Network Traffic
definition: Outbound internet RPC traffic is RPC traffic that is: (a) on an outgoing connection initiated from a host within a network to a host outside the network, and (b) using a standard RPC protocol.

Outbound Internet Web Traffic
type: Class
subclass of: Outbound Internet Network Traffic
subclass of: Web Network Traffic
subclass of: Restriction
  on property: may-contain
  some values from: URL
type: NamedIndividual
may-contain: URL
definition: Outbound internet web traffic is network traffic that is: (a) on an outgoing connection initiated from a host within a network to a host outside the network, and (b) using a standard web protocol.

Outbound Network Traffic
type: Class
subclass of: Network Traffic
type: NamedIndividual
definition: Outbound traffic is network traffic originating from a host of interest (client), to another host (server).

Outbound Traffic Filtering
type: Class
subclass of: Network Traffic Filtering
subclass of: Restriction
  on property: filters
  some values from: Outbound Network Traffic
type: NamedIndividual
filters: Outbound Network Traffic
kb-reference: Reference-AutomaticallyGeneratingRulesForConnectionSecurity Microsoft
d3fend-id: D3-OTF
definition: Restricting network traffic originating from a private host or enclave destined towards untrusted networks.
kb-article: ## How it works Outbound traffic, in this context, is network traffic originating from a private host or enclave destined towards untrusted networks. For example: * An enterprise desktop intranet user connecting to www.example.com * An internal mail server connecting to an external mail server, mail.example.com Filtering is commonly implemented as firewall rulesets to limit outbound traffic permitted to egress a host or network. Firewalls are deployed either directly on hosts through kernel level software implementations or installed in-line directly on network links. There are benefits and disadvantages to each approach. There are various strategies for developing filtering rulesets: * Block everything by default * Limit destination hosts * Limit destination transport or application protocols * Restrict content outbound (Ex. strings formatted as social security numbers, or proprietary data) ## Considerations * Dynamic IP assignment creates challenges for Outbound Traffic Filtering because users are not necessarily associated with the same IP address. This can be addressed by linking IP address management information with the filtering logic. * Connections using non-standard transport layer ports may circumvent outbound traffic filtering technology which does not detect application protocol based on traffic content. * Business requirements typically drive the development of filtering rule sets. ## Implementations - iptables (Linux) - Windows Firewall - pf (BSD)

Output Device
type: Class
subclass of: Hardware Device
definition: An output device is any piece of computer hardware equipment which converts information into human-readable form. It can be text, graphics, tactile, audio, and video. Some of the output devices are Visual Display Units (VDU) i.e. a Monitor, Printer, Graphic Output devices, Plotters, Speakers etc. A new type of Output device is been developed these days, known as Speech synthesizer, a mechanism attached to the computer which produces verbal output sounding almost like human speeches.

Output Device Event
type: Class
subclass of: Hardware Device Event
subclass of: Restriction
  on property: has-participant
  some values from: Output Device
definition: An event describing the activity or state of output devices, including sound cards, display adapters, or media controllers. These events relate to audio, video, or graphics functionality.

POSIX Symbolic Link
type: Class
subclass of: Symbolic Link
subclass of: Unix Link
definition: A POSIX-compliant symbolic link. These are often fast symbolic links, but need not be.

Packet Log
type: Class
subclass of: Log
subclass of: Restriction
  on property: records
  some values from: Network Session
type: NamedIndividual
records: Network Session
definition: A log of all the network packet data captured from a network by a network sensor (i.e., packet analyzer),

Page
type: Class
subclass of: Memory Block
definition: A page, memory page, logical page, or virtual page is a fixed-length contiguous block of virtual memory, described by a single entry in the page table. It is the smallest unit of data for memory management in a virtual memory operating system.

Page Frame
type: Class
subclass of: Memory Block
subclass of: Restriction
  on property: contained-by
  some values from: Primary Storage
type: NamedIndividual
contained-by: Primary Storage
definition: A page frame is the smallest fixed-length contiguous block of physical memory into which memory pages are mapped by the operating system.

Page Table
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: contains
  some values from: Physical Address
subclass of: Restriction
  on property: contains
  some values from: Virtual Address
type: NamedIndividual
contains: Physical Address
contains: Virtual Address
definition: A page table is the data structure used by the MMU in a virtual memory computer system to store the mapping between virtual addresses (virtual pages) and physical addresses (page frames).

Parameter-based Transfer Learning
type: Class
subclass of: Homogenous Transfer Learning
type: NamedIndividual
d3fend-id: D3A-PBTL
definition: The idea behind parameter-based methods is that a well-trained model on the source domain has learned a well-defined structure, and if two tasks are related, this structure can be transferred to the target model.
kb-article: ## References Georgian Impact Blog. (n.d.). Transfer Learning Part 1. [Link](https://medium.com/georgian-impact-blog/transfer-learning-part-1-ed0c174ad6e7#:~:text=Homogeneous%20Transfer%20Learning-,1.,the%20target%20domain%20for%20training).

Parametric Tests
type: Class
subclass of: Hypothesis Testing
type: NamedIndividual
d3fend-id: D3A-PT
definition: A parametric test relies upon the assumption that the data you want to test is (or approximately is) normally distributed.
kb-article: ## References Newcastle University. (n.d.). Parametric Hypothesis Tests. [Link](https://www.ncl.ac.uk/webtemplate/ask-assets/external/maths-resources/psychology/parametric-hypothesis-tests.html)

Parent Process
type: Class
subclass of: Process
definition: In computing, a parent process is a process that has created one or more child processes.

Partial Matching
type: Class
subclass of: String Pattern Matching
type: NamedIndividual
d3fend-id: D3A-PM
definition: Partial string pattern matching is a special case of string pattern matching where one seeks to find a pattern within a larger string (text). It allows for the detection of patterns that occur as substrings or partial segments within the full string, rather than requiring an exact match across the entire string.
kb-article: ## References 1. String-searching algorithm. (2023, April 8). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/String-searching_algorithm)
kb-article: Numeric pattern matching is a method of matching some defined pattern specification against a numeric value.

Partition
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: A partition is a region on secondary storage device created so that the region can be managed by itself; separate from any other regions (partitions) on that secondary storage device. Creating partitions is typically the first step of preparing a newly installed storage device, before any file system is created. The device stores the information about the partitions' locations and sizes in an area known as the partition table that the operating system reads before any other part of the disk. Each partition then appears to the operating system as a distinct "logical" storage device that uses part of the actual device. System administrators use a program called a partition editor to create, resize, delete, and manipulate the partitions. Partitioning allows the use of different filesystems to be installed for different kinds of files. Separating user data from system data can prevent the system partition from becoming full and rendering the system unusable. Partitioning can also make backing up easier. [Definition adapted as generalization from definition of disk partitioning and distinct from in-memory partitions.]
alternative label: Disk Partition
alternative label: Disk Slice

Partition Table
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: addresses
  some values from: Partition
subclass of: Restriction
  on property: may-contain
  some values from: Boot Record
type: NamedIndividual
addresses: Partition
may-contain: Boot Record
definition: A partition is a fixed-size subset of a storage device which is treated as a unit by the operating system. A partition table is a table maintained on the storage device by the operating system describing the partitions on that device. The terms partition table and partition map are most commonly associated with the MBR partition table of a Master Boot Record (MBR) in IBM PC compatibles, but it may be used generically to refer to other "formats" that divide a disk drive into partitions, such as: GUID Partition Table (GPT), Apple partition map (APM), or BSD disklabel.

Passive Certificate Analysis
type: Class
subclass of: Certificate Analysis
type: NamedIndividual
kb-reference: Reference-CertificateTransparency
kb-reference: Reference-StreamingPhish
d3fend-id: D3-PCA
definition: Collecting host certificates from network traffic or other passive sources like a certificate transparency log and analyzing them for unauthorized activity.
kb-article: ## How it works Certificates are analyzed outside of a TLS server connection using third-party secure update logs, domain name analysis and analytics. ### Secure update certificate logs * Certificate Logs The key enabling feature is a secure service that maintains record logs of certificate activities. The logs allow users to only append certificates and never to delete or modify the log entries. The logs use Merkle Tree Hashes to ensure they have not been tampered with. The logging service also allows for public auditing by any user. The logging service, upon receipt of a certificate to log, will respond with a signed certificate timestamp (SCT). The SCT guarantees the certificate will be added to the log within the time specified. The SCT must be present with the certificate during a TLS handshake. * Certificate Monitoring Certificate monitoring, of the logs, is typically done by the CA and they watch for suspicious certificate logging and unusual certificates or extensions or permissions. Monitors are also responsible for verifying the logs are accurate and public. * Certificate Auditors Log integrity is verified by log auditors. Auditors make use of log proofs are used to validate the cryptographic hashes (Merkle Trees) that the log employs are consistent. In order to ensure consistency throughout multiple monitors and auditors, sharing a common logging service, gossip protocol is employed. ### Phishing domain name analysis * A curated corpus of known benign domains and phishing domain names is used as training text for machine learning. Through the use of feature set extraction, vectors labels are created with scoring to indicated if they are considered benign or phishing domains. * A stream of new or updated SSL certificates with fully qualified domain names (FQDN) is analyzed against the feature vectors and a predictive model determines a score for the domains. The scoring considers distance measures such as Levenshtein distance to help in determining the fin…

Passive Logical Link Mapping
type: Class
subclass of: Logical Link Mapping
type: NamedIndividual
kb-reference: Reference-TenablePassiveNetworkMonitoring
d3fend-id: D3-PLLM
definition: Passive logical link mapping only listens to network traffic as a means to map the the whole data link layer, where the links represent logical data flows rather than physical connections.
synonym: Passive Logical Layer Mapping

Password
type: Class
subclass of: Credential
type: NamedIndividual
definition: A password, sometimes called a passcode, is a memorized secret, typically a string of characters, usually used to confirm the identity of a user. Using the terminology of the NIST Digital Identity Guidelines, the secret is memorized by a party called the claimant while the party verifying the identity of the claimant is called the verifier. When the claimant successfully demonstrates knowledge of the password to the verifier through an established authentication protocol, the verifier is able to infer the claimant's identity.
alternative label: Passcode

Password Authentication
type: Class
subclass of: Agent Authentication
subclass of: Restriction
  on property: uses
  some values from: Password
type: NamedIndividual
kb-reference: Reference-NIST-Special-Publication-800-53-Revision-5
uses: Password
d3fend-id: D3-PWA
definition: Password authentication is a security mechanism used to verify the identity of a user or entity attempting to access a system or resource by requiring the input of a secret string of characters, known as a password, that is associated with the user or entity.

Password Database
type: Class
subclass of: Database
definition: A password database is a database that holds passwords for user accounts and is usually encrypted (i.e.., the passwords are hashed). Password databases are found supporting system services (such as SAM) or part of user applications such as password managers.

Password File
type: Class
subclass of: File
subclass of: Password Database
type: NamedIndividual
definition: Simple form of password database held in a single file (e.g., /etc/password)

Password Manager
type: Class
subclass of: Application
definition: A password manager is a software application or hardware that helps a user store and organize passwords. Password managers usually store passwords encrypted, requiring the user to create a master password: a single, ideally very strong password which grants the user access to their entire password database. Some password managers store passwords on the user's computer (called offline password managers), whereas others store data in the provider's cloud (often called online password managers). However offline password managers also offer data storage in the user's own cloud accounts rather than the provider's cloud. While the core functionality of a password manager is to securely store large collections of passwords, many provide additional features such as form filling and password generation.

Password Rotation
type: Class
subclass of: Credential Rotation
subclass of: Restriction
  on property: regenerates
  some values from: Password
type: NamedIndividual
kb-reference: Reference-PasswordandKeyRotation-SSH
regenerates: Password
d3fend-id: D3-PR
definition: Password rotation is a security policy that mandates the periodic change of user account passwords to mitigate the risk of unauthorized access due to compromised credentials.
kb-article: ## How it works Users may be requested to change their passwords on a regular schedule. Management servers with enterprise policies for account management provide the ability to change or reset passwords for accounts. ## Considerations Requiring users to change their passwords frequently can result in insecure password practices by the user. The latest update of NIST SP 800-63B, Digital Identity Guidelines, recommends requiring password reset only when a known compromise has occurred, or every 365 days, rather than every 60 or 90 days.

Password Store
type: Class
subclass of: Password Database
type: NamedIndividual
definition: A user repository of account passwords, often accessed via a password manager.

Patent Reference
type: Class
subclass of: Technique Reference
pref-label: Patent

Pattern Matching
type: Class
subclass of: Logical Rules
type: NamedIndividual
d3fend-id: D3A-PM
definition: Pattern matching is the act of checking a given sequence of tokens for the presence of the constituents of some pattern.
kb-article: ## References 1. Pattern matching. (2023, May 20). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Pattern_matching)

Pearson's Correlation Coefficient
type: Class
subclass of: Correlation
type: NamedIndividual
d3fend-id: D3A-PCC
kb-article: ## References Wolfram MathWorld. (n.d.). Correlation Coefficient. [Link](https://mathworld.wolfram.com/CorrelationCoefficient.html)

Per Host Download-Upload Ratio Analysis
type: Class
subclass of: Network Traffic Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Network Traffic
type: NamedIndividual
analyzes: Network Traffic
kb-reference: Reference-SystemForDetectingThreatsUsingScenario-basedTrackingOfInternalAndExternalNetworkTraffic VECTRANETWORKSInc
d3fend-id: D3-PHDURA
definition: Detecting anomalies that indicate malicious activity by comparing the amount of data downloaded versus data uploaded by a host.
kb-article: ## How it works Aggregate pull vs. push ratios from metadata are used to develop a baseline for a given host over a specific time period, e.g., over a three-hour period, one day, one week, etc. Anomalies identified over a threshold produce an alert. ## Considerations Collection and analysis of large network packet captures requires large storage and intensive computing power. The time windows used to calculate the ratio may vary in implementations, this consideration should take into account a threat model and likely effects (impacts) delivered by an adversary.

Peripheral Device Event
type: Class
subclass of: Hardware Device Event
subclass of: Restriction
  on property: has-participant
  some values from: Removable Media Device
definition: An event involving external or auxiliary devices, such as USB drives, Thunderbolt peripherals, or Bluetooth devices. Peripheral events provide visibility into resource availability and potential unauthorized access.

Peripheral Firmware
type: Class
subclass of: Firmware
type: NamedIndividual
definition: Firmware that is installed on computer peripheral devices.

Peripheral Firmware Verification
type: Class
subclass of: Firmware Verification
subclass of: Restriction
  on property: verifies
  some values from: Peripheral Firmware
type: NamedIndividual
kb-reference: Reference-FirmwareVerificationEclypsium
kb-reference: Reference-FirmwareVerificationTrapezoid
verifies: Peripheral Firmware
d3fend-id: D3-PFV
definition: Cryptographically verifying peripheral firmware integrity.
kb-article: # How it works Peripherial firmware is collected and analyzed on a host either periodically or on demand. This information may be collected for future comparisons. Changes in firmware hash values may indicate that the firmware has been tampered with or that firmware images are not maintained to current baselined versions, or even known vulnerable versions are deployed. ## Considerations * Trust baselines will need to be generated for specific devices * Changes to trusted configurations will need to be managed across the enterprise

Peripheral Hub Firmware
type: Class
subclass of: Peripheral Firmware
definition: Firmware that is installed on peripheral hub device such as a USB or Firewire hub.
alternative label: USB Hub Firmware

Permission Granting Event
type: Class
subclass of: Access Control Administration Event
definition: An administrative event where authorization is given, allowing a subject to perform specific operations on a protected resource, effectuating a policy decision to allow access rights.

Permission Revoking Event
type: Class
subclass of: Access Control Administration Event
definition: An administrative event entailing the withdrawal of previously granted access rights, reconfiguring permissions to prevent a subject from performing specific actions on a resource, in accordance with updated access policies.

Persistence Technique
type: Class
subclass of: ATTACK Enterprise Technique
subclass of: Offensive Technique
subclass of: Restriction
  on property: enables
  some values from: Persistence
type: NamedIndividual
enables: Persistence

Person
type: Class
subclass of: Agent
subclass of: Restriction
  on property: name
  some values from: string
type: NamedIndividual

Personal Computer
type: Class
subclass of: Client Computer
definition: A personal computer (PC) is a multi-purpose computer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or technician. Unlike large, costly minicomputers and mainframes, time-sharing by many people at the same time is not used with personal computers. PCs have in practice become powerful enough that they may be shared by multiple users at any given time, though this is not common practice nor the primary purpose of a PC.

Perturbation-based Learning
type: Class
subclass of: Intrinsically Semi-supervised Learning
type: NamedIndividual
d3fend-id: D3A-PBL
definition: Perturbation based methods are proposed under the smoothness assumption, which indicates that two data points close to each other in feature space are likely to have the same label.
kb-article: ## References Zheng, Y., & Song, Y. (2021). An Effective Perturbation-Based Semi-Supervised Learning Method for Acoustic Event Classification. IEEE/ACM Transactions on Audio, Speech, and Language Processing, 29, 3580-3591. [Link](https://www.semanticscholar.org/paper/An-Effective-Perturbation-Based-Semi-Supervised-for-Zheng-Song/b75ae37d137ac354eb2ed42917e461b4dccdc977). Engelen, S., & Hoos, H. (2020). A survey on semi-supervised learning. Machine Learning, 109(2), 299-337. [Link](https://link.springer.com/article/10.1007/s10994-019-05855-6).

Phi Coefficient
type: Class
subclass of: Correlation
type: NamedIndividual
d3fend-id: D3A-PC
definition: The phi coefficient (or mean square contingency coefficient is a measure of association for two binary variables.
kb-article: ## References \Wikipedia. (n.d.). Phi coefficient. [Link](https://en.wikipedia.org/wiki/Phi_coefficient)
synonym: MCC
synonym: Matthews Correlation Coefficient (in machine learning)

Physical Access Mediation
type: Class
subclass of: Access Mediation
subclass of: Restriction
  on property: isolates
  some values from: Physical Artifact
type: NamedIndividual
isolates: Physical Artifact
kb-reference: Reference-CNNSI-4009
d3fend-id: D3-PAM
definition: Physical access mediation is the process of granting or denying specific requests to enter specific physical facilities (e.g., Federal buildings, military establishments, border crossing entrances.)
synonym: Physical Access Control

Physical Address
type: Class
subclass of: Memory Address
type: NamedIndividual
definition: In a computer supporting virtual memory, the term physical address is used mostly to differentiate from a virtual address. In particular, in computers utilizing a memory management unit(MMU) to translate memory addresses, the virtual and physical addresses refer to an address before and after translation performed by the MMU, respectively.

Physical Artifact
type: Class
subclass of: Artifact
subclass of: Restriction
  on property: has-location
  some values from: Physical Location
type: NamedIndividual
alternative label: Physical Object

Physical Link
type: Class
subclass of: Link
type: NamedIndividual
definition: A physical link is a dedicated connection for communication that uses some physical media (electrical, electromagnetic, optical, to include clear spaces or vacuums.) A physical link represents only a single hop (link) in any larger communcations path, circuit, or network. NOTE: not synonymous with data link as a data link can be over a telecommunications circuit, which may be a virtual circuit composed of multiple phyical links.
synonym: Layer-1 Link

Physical Link Mapping
type: Class
subclass of: Network Mapping
subclass of: Restriction
  on property: maps
  some values from: Network Node
subclass of: Restriction
  on property: maps
  some values from: Physical Link
type: NamedIndividual
kb-reference: Reference-LibreNMSDocsNetworkMapExtension
maps: Network Node
maps: Physical Link
d3fend-id: D3-PLM
definition: Physical link mapping identifies and models the link connectivity of the network devices within a physical network.
synonym: Layer 1 Mapping

Physical Location
type: Class
subclass of: D3FEND Core
type: NamedIndividual
definition: The terms location [here, a physical location] and place in geography are used to identify a point or an area on the Earth's surface or elsewhere. The term location generally implies a higher degree of certainty than place, which often indicates an entity with an ambiguous boundary, relying more on human or social attributes of place identity and sense of place than on geometry. The distinction between space and place is considered a central concern of geography, and has been addressed by scholars such as Yi-Fu Tuan and John Agnew.

Pipe
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: In Unix-like computer operating systems, a pipeline is a mechanism for inter-process communication using message passing. In the strictest sense, a pipe is a single segment of a pipeline, allowing one process to pass information forward to another. Network pipes allow processes on different hosts to interact.
alternative label: Pipeline

Pix2Pix
type: Class
subclass of: Image-to-Image Translation GAN
type: NamedIndividual
d3fend-id: D3A-PIX
definition: Pix2Pix is based on condtional GAN architecture and are trained on paired set of images or scenes from two domains to be used for translation.
kb-article: ## References Esri. (n.d.). How Pix2Pix Works. [Link](https://developers.arcgis.com/python/guide/how-pix2pix-works/)

Plan
type: Class
subclass of: D3FEND Core

Planning
type: Class
subclass of: Analytical Purpose

Platform Hardening
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Harden
type: NamedIndividual
enables: Harden
d3fend-id: D3-PH
definition: Hardening components of a Platform with the intention of making them more difficult to exploit. Platforms includes components such as: * BIOS UEFI Subsystems * Hardware security devices such as Trusted Platform Modules * Boot process logic or code * Kernel software components
synonym: Endpoint Hardening
synonym: System Hardening

Platform Monitoring
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Detect
type: NamedIndividual
enables: Detect
d3fend-id: D3-PM
definition: Monitoring platform components such as operating systems software, hardware devices, or firmware.
kb-article: Platform monitoring consists of the analysis and monitoring of system level devices and low-level components, including hardware devices, to detect unauthorized modifications or suspicious activity. Monitored platform components includes system files and embedded devices such as: * Kernel software modules * Boot process code and load logic * Operating system components and device files * System libraries and dynamically loaded files * Hardware device drivers * Embedded firmware devices

Point-biserial Correlation Coefficient
type: Class
subclass of: Correlation
type: NamedIndividual
d3fend-id: D3A-PBCC
definition: The point biserial correlation coefficient (rpb) is a correlation coefficient used when one variable (e.g. Y) is dichotomous; Y can either be "naturally" dichotomous, like whether a coin lands heads or tails, or an artificially dichotomized variable.
kb-article: ## References Wikipedia. (n.d.). Point-biserial correlation coefficient. [Link](https://en.wikipedia.org/wiki/Point-biserial_correlation_coefficient)

Point Estimation
type: Class
subclass of: Estimation
type: NamedIndividual
d3fend-id: D3A-PE
definition: A point estimation is a single value that estimates the parameter. Point estimates are single values calculated from the sample
kb-article: ## References Pennsylvania State University. (n.d.). Statistical Inference and Estimation. [Link](https://online.stat.psu.edu/stat504/lesson/statistical-inference-and-estimation)

Pointer
type: Class
subclass of: Digital Information
type: NamedIndividual
definition: In computer science, a pointer is a programming language object, whose value refers to (or "points to") another value stored elsewhere in the computer memory using its memory address. A pointer references a location in memory, and obtaining the value stored at that location is known as dereferencing the pointer. As an analogy, a page number in a book's index could be considered a pointer to the corresponding page; dereferencing such a pointer would be done by flipping to the page with the given page number.

Pointer Authentication
type: Class
subclass of: Application Hardening
subclass of: Restriction
  on property: authenticates
  some values from: Pointer
type: NamedIndividual
authenticates: Pointer
kb-reference: Reference-PointerAuthenticationOnARMv8.3
kb-reference: Reference-PointerAuthenticationProjectZero
d3fend-id: D3-PAN
definition: Comparing the cryptographic hash or derivative of a pointer's value to an expected value.
kb-article: ## How It Works Pointer Authentication (frequently referred to as PAC, although the technique is properly Pointer Authentication) is a security feature to provide protection against attackers with memory read/write access. A Pointer Authentication Code (PAC) is a cryptographic hash or derivative computed on the value of a pointer and some additional context information which can then provide a cryptographically strong guarantee about the likelihood that a pointer has been tampered with by an attacker. Although pointers are 64 bits, most systems have a substantially smaller virtual address space, leaving unused bits in pointers that can store the value of the PAC, this can be done to reduce memory space requirements. One implementation is in ARMv8.3-A. A PAC is computed over the 64-bit pointer value and a 64-bit context value. Instructions are introduced to deal with pointers: one category to compute and insert the PAC into a pointer, another category to verify the pointer and invalidate the pointer if the PAC does not check, and a third category to remove the pointer and restore the original value without verifying. The ARM standard specifies a cryptographic algorithm called QARMA-64 (designed by Qualcomm) to compute the signature, although this algorithm is not required. The architecture provides for five secret 128-bit Pointer Authentication keys: two for instruction pointers, two for data pointers, and a general key for signing larger blocks of data. ## Considerations In the ARM implementation, the mechanisms above for manipulating PACS are provided, but it is up to the code developer to manage the keys for the cryptographic algorithm. A known potential limitation of PACs concerns signing gadgets. Under certain circumstances PACs can be bypassed by forcing the system to run a signing gadget which will allow the signing of arbitrary pointers to occur.

Pointer Dereferencing Function
type: Class
subclass of: Subroutine
subclass of: Restriction
  on property: addresses
  some values from: Memory Block
subclass of: Restriction
  on property: addresses
  some values from: Pointer
type: NamedIndividual
addresses: Memory Block
addresses: Pointer
definition: A function which has an operation which dereferences a pointer.
comment: Note, this is not the actual code which performs the dereferencing operation internal to an application runtime.

Pointer Validation
type: Class
subclass of: Source Code Hardening
type: NamedIndividual
kb-reference: Reference-PointerValidationFunction SEI
d3fend-id: D3-PV
definition: Ensuring that a pointer variable has the required properties for use.

Policy Gradient
type: Class
subclass of: Model-free Reinforcement Learning
type: NamedIndividual
d3fend-id: D3A-PG
definition: The objective of a Reinforcement Learning Policy Gradient agent is to maximize the “expected” reward when following a policy
kb-article: ## References Policy Gradients in a Nutshell. Towards Data Science. [Link](https://towardsdatascience.com/policy-gradients-in-a-nutshell-8b72f9743c5d).

Policy Reference
type: Class
subclass of: Technique Reference
pref-label: Policy

PowerShell Profile Script
type: Class
subclass of: User Init Script
type: NamedIndividual
definition: A PowerShell profile script is a script that runs when PowerShell starts and can be used as a logon script to customize user environments.

Power Supply
type: Class
subclass of: Hardware Device
definition: A power supply is an electrical device or module that converts and regulates energy from a source (e.g., the power grid or batteries) to an appropriate voltage, current, and frequency for one or more loads. It may stand alone or be integrated into its host appliance, often providing overcurrent protection, voltage regulation, or power conditioning for safe, stable operation.

Power and Thermal Device Event
type: Class
subclass of: Hardware Device Event
subclass of: Restriction
  on property: has-participant
  some values from: Sensor
definition: An event involving power supplies, batteries, or thermal management devices. These events represent changes in power states, temperature thresholds, or cooling system activity.

Pre-Authentication Event
type: Class
subclass of: Authentication Event
subclass of: Restriction
  on property: precedes
  some values from: Authentication
definition: An event representing preparatory steps or processes conducted prior to the primary authentication operation. Pre-authentication often involves initial protocol exchanges, cryptographic challenges, or the validation of supplemental factors (e.g., pre-shared keys) to ensure the readiness and security of the authentication workflow.

Predicate Logic
type: Class
subclass of: Symbolic AI
type: NamedIndividual
d3fend-id: D3A-PL
definition: Predicate logic is is collection of formal systems used in mathematics, philosophy, linguistics, and computer science. First-order logic and Higher-order logic both incorporate predicate logic.
kb-article: ## References 1. First-order logic. (2023, May 26). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/First-order_logic) 2. Higher-order logic. (2023, May 13) [Link](https://en.wikipedia.org/wiki/Higher-order_logic)

Primary Storage
type: Class
subclass of: Hardware Device
subclass of: Storage
subclass of: Restriction
  on property: contains
  some values from: Page Frame
subclass of: Restriction
  on property: contains
  some values from: Process Segment
type: NamedIndividual
contains: Page Frame
contains: Process Segment
definition: Primary memory of a computer is memory that is wired directly to the processor, consisting of RAM and possibly ROM. These terms are used in contrast to mass storage devices and cache memory (although we may note that when a program accesses main memory, it is often actually interacting with a cache).

Principal Component Analysis
type: Class
subclass of: Multivariate Analysis
type: NamedIndividual
d3fend-id: D3A-PCA
definition: Principal components analysis (PCA) creates a new set of orthogonal variables that contain the same information as the original set. It rotates the axes of variation to give a new set of orthogonal axes, ordered so that they summarize decreasing proportions of the variation.
kb-article: ## References Wikipedia. (n.d.). Multivariate statistics. [Link](https://en.wikipedia.org/wiki/Multivariate_statistics)
synonym: PCA

Principal Components Analysis
type: Class
subclass of: Dimension Reduction
type: NamedIndividual
d3fend-id: D3A-PCA
definition: Principal Component Analysis (PCA) is a statistic-based method of identifying patterns in a large dataset while increasing interpretability and preserving information.
kb-article: ## References Wikipedia. (n.d.). Principal component analysis. [Link](https://en.wikipedia.org/wiki/Principal_component_analysis)

Print Server
type: Class
subclass of: Server
definition: A print server, or printer server, is a device that connects printers to client computers over a network. It accepts print jobs from the computers and sends the jobs to the appropriate printers, queuing the jobs locally to accommodate the fact that work may arrive more quickly than the printer can actually handle.

Private Key
type: Class
subclass of: Asymmetric Key
type: NamedIndividual
definition: A private key can be used to decrypt messages encrypted using the corresponding public key, or used to sign a message that can be authenticated with the corresponding public key.

Privilege Escalation Technique
type: Class
subclass of: ATTACK Enterprise Technique
subclass of: Offensive Technique
subclass of: Restriction
  on property: enables
  some values from: Privilege Escalation
type: NamedIndividual
enables: Privilege Escalation

Privileged User Account
type: Class
subclass of: User Account
definition: A privileged account is a user account that has more privileges than ordinary users. Privileged accounts might, for example, be able to install or remove software, upgrade the operating system, or modify system or application configurations. They might also have access to files that are not normally accessible to standard users. Typical examples are root and administrator accounts. But there also service accounts, system accounts, etc. Privileged accounts are especially powerful, and should be monitored especially closely.

Probabilistic Logic
type: Class
subclass of: Symbolic AI
type: NamedIndividual
d3fend-id: D3A-PL
definition: Probabilistic logic extends traditional logic truth tables with probabilistic expressions.
kb-article: ## References 1. Probabilistic logic. (2023, June 5). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Probabilistic_logic)

Procedure
type: Class
subclass of: Plan
subclass of: Restriction
  on property: implements
  some values from: Technique
subclass of: Restriction
  on property: start
  all values from: Step

Process
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: contains
  some values from: Process Image
subclass of: Restriction
  on property: instructed-by
  some values from: Software
subclass of: Restriction
  on property: may-execute
  some values from: Thread
subclass of: Restriction
  on property: process-image-path
  some values from: Executable Binary
subclass of: Restriction
  on property: process-user
  some values from: User Account
subclass of: Restriction
  on property: uses
  some values from: Resource
subclass of: Restriction
  on property: process-command-line-arguments
  some values from: string
subclass of: Restriction
  on property: process-environmental-variables
  some values from: string
subclass of: Restriction
  on property: process-identifier
  some values from: integer
subclass of: Restriction
  on property: process-security-context
  some values from: string
type: NamedIndividual
contains: Process Image
instructed-by: Software
may-execute: Thread
process-image-path: Executable Binary
process-user: User Account
uses: Resource
definition: A process is an instance of a computer program that is being executed. It contains the program code and its current activity. Depending on the operating system (OS), a process may be made up of multiple threads of execution that execute instructions concurrently. A computer program is a passive collection of instructions, while a process is the actual execution of those instructions. Several processes may be associated with the same program; for example, opening up several instances of the same program often means more than one process is being executed.

Process Access Event
type: Class
subclass of: Process Event
definition: An event where one process interacts with another, such as reading memory, inspecting state, or altering behavior.

Process Analysis
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Detect
type: NamedIndividual
enables: Detect
d3fend-id: D3-PA
definition: Process Analysis consists of observing a running application process and analyzing it to watch for certain behaviors or conditions which may indicate adversary activity. Analysis can occur inside of the process or through a third-party monitoring application. Examples include monitoring system and privileged calls, monitoring process initiation chains, and memory boundary allocations.

Process Code Segment
type: Class
subclass of: Process Segment
subclass of: Restriction
  on property: contains
  some values from: Subroutine
subclass of: Restriction
  on property: may-contain
  some values from: Process Segment
type: NamedIndividual
contains: Subroutine
may-contain: Process Segment
definition: A process code segment, also known as a text segment or simply as text, is a portion of the program's virtual address space that contains executable instructions and corresponds to the loaded image code segment. Includes additional sections such as an import table.
alternative label: Process Text Segment

Process Code Segment Verification
type: Class
subclass of: Process Analysis
subclass of: Restriction
  on property: verifies
  some values from: Process Code Segment
type: NamedIndividual
kb-reference: Reference-Anti-tamperSystemWithSelf-adjustingGuards ARXANTECHNOLOGIESInc
kb-reference: Reference-GuardsForApplicationInSoftwareTamperproofing PurdueResearchFoundation
kb-reference: Reference-SystemAndMethodForDetectingMalwareInjectedIntoMemoryOfAComputingDevice EndgameInc
kb-reference: Reference-SystemAndMethodForValidatingIn-memoryIntegrityOfExecutableFilesToIdentifyMaliciousActivity EndgameInc
kb-reference: Reference-TamperProofMutatingSoftware ARXANTECHNOLOGIESInc
kb-reference: Reference-ThreatDetectionThroughTheAccumulatedDetectionOfThreatCharacteristics SophosLtd
verifies: Process Code Segment
d3fend-id: D3-PCSV
definition: Comparing the "text" or "code" memory segments to a source of truth.
kb-article: ## How it works A process code segment is an executable portion of computer memory allocated to a particular process. Process Code Segment Verification implements verification to compare a process code segment to some expected value. ### Verification logic Verification can occur during application startup, or continuously during execution. The logic which verifies the process code may be separate in a third-party process, embedded in the application itself at compile time, or dynamically linked at runtime. ### System of record Examples of systems of record: * On-disk application binary files or checksums * Remotely stored binary data or checksums * Embedded binary data or checksums ### Post Verification Actions If the verification function determines a process code segment may have been altered, a capability may invoke Eviction techniques as **Process Termination** to end the current process, or **Executable Blacklisting** to prevent the executable from launching in the future. ## Considerations ### False positives False positives commonly occur in the case that the layout of code in the process segment is legitimately modified: * Operating system features or third-party security software may modify the layout of process code, for example in the defensive technique **Segment Address Offset Randomization**, or in the case that a module is rebased. In both of these cases, the alteration occurs before the code is fully loaded into memory, and it would be possible to avoid the false positive by securely feeding this constant offset and any relocation data into the verification logic. * Process code segments may be written to modify themselves or other process code segments; however, this goes against widely-accepted current practices in software development. ### False negatives False negatives can occur via alteration of the verification logic or source of truth, or insufficient verification logic. * Verification techniques which are executed only locally may be defeate…

Process Creation Event
type: Class
subclass of: Process Event
definition: An event where a new process is spawned, initializing its execution context and resource allocation.

Process Data Segment
type: Class
subclass of: Process Segment
definition: A process data segment, is a portion of the program's virtual address space that contains executable instructions and corresponds to the loaded image data segment.

Process Environment Variable
type: Class
subclass of: Application Configuration
type: NamedIndividual
definition: An environment variable is a dynamic-named value that can affect the way running processes will behave on a computer. They are part of the environment in which a process runs.
alternative label: Environment Variable

Process Event
type: Class
subclass of: Digital Event
subclass of: Restriction
  on property: has-participant
  some values from: Process
definition: An event capturing lifecycle transitions, interactions, or activities of computer processes, including their creation, termination, and inter-process communication.

Process Eviction
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Evict
type: NamedIndividual
enables: Evict
kb-reference: Reference-MalwareDetectionUsingLocalComputationalModels CrowdstrikeInc
d3fend-id: D3-PE
definition: Process eviction techniques terminate or remove running process.

Process Image
type: Class
subclass of: Computing Image
subclass of: Restriction
  on property: contains
  some values from: Process Segment
type: NamedIndividual
contains: Process Segment
definition: A process image is a copy of a given process's state at a given point in time. It is often used to create persistence within an otherwise volatile system.

Process Lineage Analysis
type: Class
subclass of: Process Spawn Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Process
subclass of: Restriction
  on property: analyzes
  some values from: Process Tree
type: NamedIndividual
analyzes: Process
analyzes: Process Tree
kb-reference: Reference-CommandLaunchedFromWinLogon MITRE
kb-reference: Reference-DebuggersForAccessibilityApplications MITRE
kb-reference: Reference-GenericRegsvr32 MITRE
kb-reference: Reference-OutlierParentsOfCmd MITRE
kb-reference: Reference-ProcessesSpawningCmd.exe MITRE
kb-reference: Reference-QuickExecutionOfASeriesOfSuspiciousCommands MITRE
kb-reference: Reference-Reg.exeCalledFromCommandShell MITRE
kb-reference: Reference-RemotelyLaunchedExecutablesViaWMI MITRE
kb-reference: Reference-ServiceOutlierExecutables MITRE
kb-reference: Reference-ServiceSearchPathInterception MITRE
kb-reference: Reference-ServicesLaunchingCmd MITRE
kb-reference: Reference-SystemAndMethodsThereofForCausalityIdentificationAndAttributionsDeterminationOfProcessesInANetwork PaloAltoNetworksIncCyberSecdoLtd
kb-reference: Reference-SystemAndMethodsThereofForIdentificationOfSuspiciousSystemProcesses PaloAltoNetworksInc
kb-reference: Reference-UACBypass MITRE
kb-reference: Reference-CAR-2020-11-002:LocalNetworkSniffing MITRE
kb-reference: Reference-CAR-2020-11-004:ProcessesStartedFromIrregularParent MITRE
kb-reference: Reference-CAR-2021-02-002:GetSystemElevation MITRE
kb-reference: Reference-CAR-2021-05-003:BCDEditFailureRecoveryModification MITRE
d3fend-id: D3-PLA
definition: Identification of suspicious processes executing on an end-point device by examining the ancestry and siblings of a process, and the associated metadata of each node on the tree, such as process execution, duration, and order relative to siblings and ancestors.
kb-article: ## How it works Process tree analysis techniques gather information on how a process was initiated to determine if a process is malicious. For example, if a process was not initiated from boot or not initiated by another process, that process is identified as suspicious. Also, if a new process was started before a process initiated by the device (ex. during boot) and that new process was not initiated by a user (which can be determined by examining process parameters such as type of process, its creator, source, etc.) the process is identified as suspicious. For example, Microsoft Word may block execution of any subprocess that is not in an approved path. ## Considerations * Attackers may spoof the parent PID (https://attack.mitre.org/techniques/T1502/), rendering such after-the-fact analysis on process lineage ineffective. * Processes may hide from various means of detection; an example on Linux is where a rootkit might remove key files for the process from its directory in /proc. * Zombie processes.
synonym: Process Tree Analysis

Process Segment
type: Class
subclass of: Binary Segment
type: NamedIndividual
definition: Process segments are distinct partitions of the memory space of a running process. Heap, data, code, and stack segments are examples of process segments.
synonym: Process Memory

Process Segment Execution Prevention
type: Class
subclass of: Application Hardening
subclass of: Restriction
  on property: neutralizes
  some values from: Process Segment
type: NamedIndividual
kb-reference: Reference-DataExecutionPrevention Microsoft
kb-reference: Reference-WhatIsNX XDFeature RedHat
neutralizes: Process Segment
d3fend-id: D3-PSEP
definition: Preventing execution of any address in a memory region other than the code segment.
kb-article: ## How it works During execution of a process, the instruction pointer register should only point to addresses in a code segment (also called the .text segment), as this is the sole segment which should contain program code. When this technique detects an attempt to execute something that has been designated as non-executable, other techniques such as those in **Process Eviction** might be invoked, such as **Process Termination** to end the current process, or **Executable Blacklisting** to blacklist the potentially vulnerable or malfunctioning executable. ### Software-based implementations The software-based implementation in Windows XP SP2 might not check that every time the instruction pointer is changed, and does not check on each jump or return. Before calling an exception handler, Windows XP SP2 software-enforced DEP checks whether the exception handler is located in a memory region marked as executable. If the program was also built with SafeSEH, this implementation also checks before changing control to the exception handler whether it is a registered exception handler in the program's file on disk. ### Hardware-based implementations The NX (No Execute) or XD (Execute Disable) bit on the processor specifies whether a certain part of memory is executable. Early implementations set this bit by the memory segment, while modern implementations which are built on the flat memory model often store this bit in each entry of the page table, to control execution by the page. ## Considerations Non-hardware process data segment execution prevention is more susceptible to being able to be turned off for a page of memory. Different implementations of this defense have been in place since the 1980s, but implementation stalled when larger 16-bit programs began stuffing code in the segments usually reserved for data. Many modern programs follow the best practice of separation of code and data, are able to run under this defense. ROP or ret2libc/return-to-function attacks co…
synonym: Execute Disable
synonym: No Execute

Process Self-Modification Detection
type: Class
subclass of: Process Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Process
type: NamedIndividual
analyzes: Process
kb-reference: Reference-SystemAndMethodForProcessHollowingDetection CarbonBlackInc
d3fend-id: D3-PSMD
definition: Detects processes that modify, change, or replace their own code at runtime.
kb-article: ## How it Works A security agent installed on the host machine intercepts API calls between a process and operating system. Intercepted API calls are then compared against attack signatures/patterns to identify API calls that modify executable memory or modify the entry point address of a suspended child process. Attack patterns include: * Executable code of a suspended child process removed from memory by one or more API calls. * New executable code injected and / or loaded into memory of a suspended child process by one or more API calls. * Executable code modified by one or more API calls. * Next instruction pointer value in memory modified by one or more API calls. ## Considerations Comparing loaded code segments of processes with what is expected to have been loaded from a file can result in false positives, due to legitimate uses of self-modification for decrypting or uncompressing code segments.

Process Set User ID Event
type: Class
subclass of: Process Event
definition: An event where a process changes or adopts a specific user identity, modifying its access privileges or operational context.

Process Spawn Analysis
type: Class
subclass of: Process Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Create Process
subclass of: Restriction
  on property: analyzes
  some values from: Process
type: NamedIndividual
analyzes: Create Process
analyzes: Process
kb-reference: Reference-ActiveDirectoryDumpingViaNTDSUtil MITRE
kb-reference: Reference-CommandLineUsageOfArchivingSoftware MITRE
kb-reference: Reference-CreateRemoteProcessViaWMIC MITRE Other
kb-reference: Reference-CredentialDumpingViaMimikatz MITRE
kb-reference: Reference-HostDiscoveryCommands MITRE
kb-reference: Reference-LsassProcessDumpViaProcdump MITRE
kb-reference: Reference-PowershellExecution MITRE
kb-reference: Reference-RunDLL32.exeMonitoring MITRE
kb-reference: Reference-Squiblydoo MITRE
kb-reference: Reference-SuspiciousArguments MITRE
kb-reference: Reference-SuspiciousRunLocations MITRE
kb-reference: Reference-CAR-2020-04-001:ShadowCopyDeletion MITRE
kb-reference: Reference-CAR-2020-05-003:RareLolBASCommandLines MITRE
kb-reference: Reference-CAR-2020-08-001:NTFSAlternateDataStreamExecution-SystemUtilities MITRE
kb-reference: Reference-CAR-2020-09-003:IndicatorBlocking-DriverUnloaded MITRE
kb-reference: Reference-CAR-2020-09-004:CredentialsInFiles&Registry MITRE
kb-reference: Reference-CAR-2020-11-001:BootOrLogonInitializationScripts MITRE
kb-reference: Reference-CAR-2020-11-003:DLLInjectionWithMavinject MITRE
kb-reference: Reference-CAR-2020-11-005:ClearPowershellConsoleCommandHistory MITRE
kb-reference: Reference-CAR-2020-11-006:LocalPermissionGroupDiscovery MITRE
kb-reference: Reference-CAR-2020-11-007:NetworkShareConnectionRemoval MITRE
kb-reference: Reference-CAR-2020-11-008:MSBuildAndMsxsl MITRE
kb-reference: Reference-CAR-2020-11-009:CompiledHTMLAccess MITRE
kb-reference: Reference-CAR-2021-01-002:UnusuallyLongCommandLineStrings MITRE
kb-reference: Reference-CAR-2021-01-003:ClearingWindowsLogsWithWevtutil MITRE
kb-reference: Reference-CAR-2021-01-004:UnusualChildProcessForSpoolsv.ExeOrConnhost.Exe MITRE
kb-reference: Reference-CAR-2021-01-006:UnusualChildProcessSpawnedUsingDDEExploit MITRE
kb-reference: Reference-CAR-2021-01-007:DetectingTamperingOfWindowsDefenderCommandPrompt MITRE
kb-reference: Reference-CAR-2021-01-008:DisableUAC MITRE
kb-reference: Reference-CAR-2021-01-009:DetectingShadowCopyDeletionViaVssadmin.exe MITRE
kb-reference: Reference-CAR-2021-02-001:Webshell-IndicativeProcessTree MITRE
kb-reference: Reference-CAR-2021-04-001:CommonWindowsProcessMasquerading MITRE
kb-reference: Reference-CAR-2021-05-001:AttemptToAddCertificateToUntrustedStore MITRE
kb-reference: Reference-CAR-2021-05-002:BatchFileWriteToSystem32 MITRE
kb-reference: Reference-CAR-2021-05-003:BCDEditFailureRecoveryModification MITRE
kb-reference: Reference-CAR-2021-05-004:BITSJobPersistence MITRE
kb-reference: Reference-CAR-2021-05-005:BITSAdminDownloadFile MITRE
kb-reference: Reference-CAR-2021-05-006:CertUtilDownloadWithURLCacheAndSplitArguments MITRE
kb-reference: Reference-CAR-2021-05-007:CertUtilDownloadWithVerifyCtlAndSplitArguments MITRE
kb-reference: Reference-CAR-2021-05-008:CertutilExeCertificateExtraction MITRE
kb-reference: Reference-CAR-2021-05-009:CertUtilWithDecodeArgument MITRE
kb-reference: Reference-CAR-2021-05-010:CreateLocalAdminAccountsUsingNetExe MITRE
d3fend-id: D3-PSA
definition: Analyzing spawn arguments or attributes of a process to detect processes that are unauthorized.
kb-article: ## How it works Process attributes are established when an operating system spawns a new process. These attributes are analyzed to look for the presence or absence of specific values or patterns. Some attributes of interest are: - user - process name - image path - security content ## Considerations - Attackers can spoof the parent process identifier (PPID), which could bypass this defense to allow execution of a malicious process from an arbitrary parent process. - Attackers could have legitimately compromised any of the process properties, such as the user, to make the execution appear legitimate. - Location: If the full image path is not checked, there could be a conflict with an executable that appears earlier due to resolution involving the system environment path/classpath variable. - Parsing issues: If the raw command from a shell is analyzed, rather than the actual function call, it is important to identify the actual command being run from its arguments. In Windows, services with unquoted file paths containing spaces will try to use the first token as the executable and the rest as arguments -- and shift tokens to the executable until a valid one is found. - Some [operating systems](/dao/artifact/d3f:OperatingSystem) can spawn processes without forking.

Process Start Function
type: Class
subclass of: Subroutine
subclass of: Restriction
  on property: invokes
  some values from: Create Process
type: NamedIndividual
invokes: Create Process
definition: A function creates a new computer process, usually by invoking a create process system call.

Process Suspension
type: Class
subclass of: Process Eviction
subclass of: Restriction
  on property: suspends
  some values from: Process
type: NamedIndividual
kb-reference: Reference-PsSuspend
suspends: Process
d3fend-id: D3-PS
definition: Suspending a running process on a computer system.
kb-article: ## How it works A running process might be suspended to mitigate its immediate effects if it is exhibiting anomalous, unauthorized, or malicious behavior. Defenders may choose to suspend rather than terminate to analyze the process first and resume the process if deemed benign. ### System-provided functions #### Windows tools In Windows, the `PsSuspend` command line utility from the SysInternals Suite provides functionality to suspend processes on a local or remote system.

Process Termination
type: Class
subclass of: Process Eviction
subclass of: Restriction
  on property: terminates
  some values from: Process
type: NamedIndividual
kb-reference: Reference-InstantProcessTerminationToolToRecoverControlOfAnInformationHandlingSystem DellProductsLP
kb-reference: Reference-MalwareDetectionUsingLocalComputationalModels CrowdstrikeInc
terminates: Process
d3fend-id: D3-PT
definition: Terminating a running application process on a computer system.
kb-article: ## How it works Processes are managed by the operating system kernel. Different operating system kernels manage the creation and termination of processes in a different manner, and expose this functionality via the kernel API. A running process might be terminated to mitigate its immediate effects if it is exhibiting anomalous, unauthorized, or malicious behavior; such as after detecting anomalous behavior via Administrative Network Activity Analysis, after a failed check from Stack Frame Canary Validation, or after System Call Analysis finds an attempt to execute an unauthorized system call. ### Proprietary technology Security software might use proprietary technology to terminate processes, instead of the system-provided functions. Further research may provide specific detail on such methods used. ### System-provided functions #### Windows tools In Windows, `ExitProcess()` is used to send a signal to a process to request it to exit, and `TerminateProcess()` is used to force a process to exit. The `taskkill` executable available in the cmd shell is used to kill a process, with the `/F` switch forcing termination as with `TerminateProcess()`. In PowerShell, `Stop-Process` is used, which is aliased by default to `spps` and `kill`. Processes started in the Windows Subsystem for Linux (WSL) environment may be terminated there with the `kill` command. In some cases, existing drivers can also be leveraged to kill processes. #### Unix/Linux tools In Unix-like systems, all process termination requests are handled using signals. The `kill` function takes the Process ID and signal to send, and is accessible with the `kill` command. Some shells have a `kill` builtin function which is separate than the `kill` binary, which can also kill background jobs in the shell and additionally perform the function faster, and can run from an existing instance of the shell if the process table is full. The signal SIGTERM specifies that the process to terminate may invoke a handler that it …

Process Termination Event
type: Class
subclass of: Process Event
definition: An event marking the cessation of a process, including resource deallocation and cleanup, either due to normal completion or abnormal termination.

Process Tree
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: contains
  some values from: Process
type: NamedIndividual
contains: Process
definition: A process tree is a tree structure representation of parent-child relationships established via process spawn operations.

Processor
type: Class
subclass of: Hardware Device
synonym: Computer Processor

Processor Component
type: Class
subclass of: Hardware Device

Processor Register
type: Class
subclass of: Primary Storage
subclass of: Restriction
  on property: contained-by
  some values from: Central Processing Unit
type: NamedIndividual
contained-by: Central Processing Unit
definition: A processor register is a quickly accessible location available to a computer's processor. Registers usually consist of a small amount of fast storage, although some registers have specific hardware functions, and may be read-only or write-only.

Product Developer
type: Class
subclass of: Provider

Progressively Growing GAN
type: Class
subclass of: Image Synthesis GAN
type: NamedIndividual
d3fend-id: D3A-PGG
definition: Progressive Growing GAN (ProGAN) is an extension to the GAN training process that allows for the stable training of generator models that can output large high-quality images.
kb-article: ## References Machine Learning Mastery. (n.d.). Introduction to Progressive Growing Generative Adversarial Networks. [Link](https://machinelearningmastery.com/introduction-to-progressive-growing-generative-adversarial-networks/)
synonym: ProGAN

Projected Clustering
type: Class
subclass of: High-dimension Clustering
type: NamedIndividual
d3fend-id: D3A-PC
definition: Projected clustering is a dimension reduction subspace clustering method.
kb-article: ## References GeeksforGeeks. (n.d.). Projected Clustering in Data Analytics. [Link](https://www.geeksforgeeks.org/projected-clustering-in-data-analytics/)

Projection-based Clustering
type: Class
subclass of: High-dimension Clustering
type: NamedIndividual
d3fend-id: D3A-PBC
definition: Projection Based Clustering is a clustering framework based on a chosen projection method and projection method a parameter-free high-dimensional data visualization technique.
kb-article: ## References R Core Team. (2021). ProjectionBasedClustering: Projection Based Clustering. [Link](https://cran.r-project.org/web/packages/ProjectionBasedClustering/ProjectionBasedClustering.pdf) Lai, J. H., Liu, Y., & Wu, W. (2017). Projection Based Clustering. [Link](https://www.researchgate.net/publication/319006501_Projection_Based_Clustering)

Prolog
type: Class
subclass of: Logic Programming
type: NamedIndividual
d3fend-id: D3A-PRO
definition: Prolog has its roots in first-order logic, a formal logic, and unlike many other programming languages.
kb-article: ## How it works Prolog is intended primarily as a declarative programming language: the program logic is expressed in terms of relations, represented as facts and rules. A computation is initiated by running a query over these relations. ## References 1. Prolog. (2023, April 5). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Prolog)

Property List File
type: Class
subclass of: Configuration File
type: NamedIndividual
definition: In the OS X, iOS, NeXTSTEP, and GNUstep programming frameworks, property list files are files that store serialized objects. Property list files use the filename extension .plist, and thus are often referred to as p-list files. Property list files are often used to store a user's settings. They are also used to store information about bundles and applications, a task served by the resource fork in the old Mac OS.
alternative label: Plist File

Propositional Logic
type: Class
subclass of: Symbolic AI
type: NamedIndividual
d3fend-id: D3A-PL
definition: Propositional logic deals with statements (i.e., propositions, which can be true or false) and relations between propositions, including the construction of arguments based on them.
kb-article: ## How it works Compound propositions are formed by connecting propositions by logical connectives. Propositions that contain no logical connectives are called atomic propositions. ## References 1. Propositional Calculus. (2022, May 31). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Propositional_calculus)
synonym: Propositional Calculus

Protocol Metadata Anomaly Detection
type: Class
subclass of: Network Traffic Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Network Traffic
type: NamedIndividual
analyzes: Network Traffic
kb-reference: Reference-MethodAndSystemForDetectingThreatsUsingMetadataVectors VECTRANETWORKSInc
kb-reference: Reference-MethodAndSystemForDetectingThreatsUsingPassiveClusterMapping VectraNetworksInc
kb-reference: Reference-SystemForImplementingThreatDetectionUsingDailyNetworkTrafficCommunityOutliers VECTRANETWORKSInc
d3fend-id: D3-PMAD
definition: Collecting network communication protocol metadata and identifying statistical outliers.
kb-article: ## How it works Network protocol metadata is first collected and processed in real-time or post-facto. Metadata may include packet header information or information about a session (ex. time between requests/responses). Metadata is then grouped based on shared characteristics and those groups are compared to each other. If particular metadata differs significantly from other data, an alert is generated, identifying the network event as anomalous. Anomalous activity may indicate unauthorized activity. ## Considerations Metadata collection on enterprises can yield large data sets. Storage, indexing, querying, and aging should be considered prior to implementation.

Provider
type: Class
subclass of: Organization

Proxy-based Web Server Access Mediation
type: Class
subclass of: Web Session Access Mediation
type: NamedIndividual
kb-reference: Reference-NIST-Special-Publication-800-41-Revision-1
d3fend-id: D3-PBWSAM
definition: Proxy-based web server access mediation focuses on the regulation of web server access through intermediary proxy servers.
kb-article: ## How it works Proxy-based Web Server Access Mediation involves controlling access to web servers via proxy servers, which act as intermediaries between users and web resources. This approach can enhance security by anonymizing user requests, filtering content, and enforcing access policies. Examples include using corporate proxies to access external websites or services.

Proxy Server
type: Class
subclass of: Computer Network Node
subclass of: Server
definition: In computer networking, a proxy server is a server application or appliance that acts as an intermediary for requests from clients seeking resources from servers that provide those resources. A proxy server thus functions on behalf of the client when requesting service, potentially masking the true origin of the request to the resource server.

Public Key
type: Class
subclass of: Asymmetric Key
type: NamedIndividual
definition: A public key can be disseminated widely as part of an asymmetric cryptography framework and be used to encrypt messages to send to the public key's owner or to authenticate signed messages from that sender.

Python Package
type: Class
subclass of: Software Package
definition: A Python package is an aggregation of many Python files - either in source code or in bytecode - and associated metadata and resources (text, images, etc.). Python packages can be distributed in different file formats.

Python Script File
type: Class
subclass of: Executable Script

Q-Learning
type: Class
subclass of: Model-free Reinforcement Learning
type: NamedIndividual
d3fend-id: D3A-QL
definition: Q-learning is a model-free reinforcement learning algorithm to learn the value of an action in a particular state. It does not require a model of the environment (hence "model-free"), and it can handle problems with stochastic transitions and rewards without requiring adaptations.
kb-article: ## References Q-learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Q-learning).

Query By Committee
type: Class
subclass of: Active Learning
type: NamedIndividual
d3fend-id: D3A-QBC
definition: Query by Committee (QBC) takes inspiration from ensemble methods. Instead of just one classifier, it takes into account the decision of a committee C=ℎ1,…,ℎc of classifiers ℎi. Each classifier has the same target classes, but a different underlying model or a different view on the data.
kb-article: ## References Intro to Active Learning. inovex Blog. [Link](https://www.inovex.de/de/blog/intro-to-active-learning/).

RAM
type: Class
subclass of: Primary Storage
definition: Random-access memory (RAM) is a form of computer memory that can be read and changed in any order, typically used to store working data and machine code.
synonym: Random-access Memory

RDP Connect Request Event
type: Class
subclass of: RDP Event
definition: An event where an RDP client sends a connection request specifying session parameters, such as display settings, compression preferences, and security requirements, to prepare for an interactive session.

RDP Connect Response Event
type: Class
subclass of: RDP Event
definition: An event where an RDP server acknowledges a connection request, finalizing session parameters and confirming the transition to an interactive remote session.

RDP Event
type: Class
subclass of: Application Layer Event
subclass of: Class
  union of: TCP Event
  union of: UDP Event
subclass of: Restriction
  on property: has-participant
  some values from: RDP Session
definition: An event involving the Remote Desktop Protocol (RDP), a communication protocol developed by Microsoft that facilitates secure remote access to graphical interfaces on desktops or applications hosted on remote servers. RDP supports multi-channel communication for transferring input, output, and management commands.

RDP Initial Request Event
type: Class
subclass of: RDP Event
definition: An event where an RDP client initiates communication with a server by sending a request to establish a session and negotiate protocol capabilities for remote interaction.

RDP Initial Response Event
type: Class
subclass of: RDP Event
definition: An event where an RDP server responds to an initial request from a client, presenting its supported capabilities and agreeing to proceed with session negotiation.

RDP Session
type: Class
subclass of: Remote Session
type: NamedIndividual
definition: A Remote Desktop Protocol (RDP) session is a session established using the RDP protocol to access Remove Desktop Services (RDS).
alternative label: Remote Desktop Session
alternative label: Terminal Services

RDP TLS Handshake Event
type: Class
subclass of: RDP Event
subclass of: TCP Event
definition: An event representing the cryptographic exchange of keys and certificates between an RDP client and server to establish a secure communication channel. The handshake ensures encryption, integrity, and authentication for the session.

RF Node
type: Class
subclass of: Network Node

RF Receiver
type: Class
subclass of: RF Node

RF Shielding
type: Class
subclass of: Platform Hardening
type: NamedIndividual
kb-reference: Reference-PrivacyAndSecuritySystemsAndMethodsOfUse
kb-reference: Reference-Technical Specifications for Construction and Management of Sensitive Compartmented Information Facilities
d3fend-id: D3-RFS
definition: Adding physical barriers to a platform to prevent undesired radio interference.

RF Transceiver
type: Class
subclass of: RF Node

RF Transmitter
type: Class
subclass of: RF Node
type: NamedIndividual

ROM
type: Class
subclass of: Primary Storage
definition: Read-only memory (ROM) is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM cannot be electronically modified after the manufacture of the memory device. Read-only memory is useful for storing software that is rarely changed during the life of the system, also known as firmware.
synonym: Read-only Memory

RPC Network Traffic
type: Class
subclass of: Network Traffic
type: NamedIndividual
definition: RPC network traffic is network traffic related to remote procedure calls between network nodes..This includes only network traffic conforming to a standard RPC protocol; not custom protocols.

RPC Traffic Analysis
type: Class
subclass of: Network Traffic Analysis
subclass of: Restriction
  on property: analyzes
  some values from: RPC Network Traffic
type: NamedIndividual
analyzes: RPC Network Traffic
kb-reference: Reference-CAR-2014-11-007-RemoteWindowsManagementInstrumentation WMI OverRPC MITRE
kb-reference: Reference-CreateRemoteProcessViaWMIC MITRE Other
kb-reference: Reference-RPCCallInterception CrowdstrikeInc
kb-reference: Reference-RemotelyLaunchedExecutablesViaServices MITRE
kb-reference: Reference-RemotelyLaunchedExecutablesViaWMI MITRE
kb-reference: Reference-RemotelyScheduledTasksViaSchtasks MITRE
kb-reference: Reference-SMBWriteRequest-NamedPipes MITRE
kb-reference: Reference-CAR-2014-05-001:RPCActivity MITRE
d3fend-id: D3-RTA
definition: Monitoring the activity of remote procedure calls in communication traffic to establish standard protocol operations and potential attacker activities.
kb-article: ## How it works A remote procedure call (RPC) enables one computer to execute a specific function on another computer, as if it were a local application process. There are numerous RPC specifications and implementations. RPC capabilities can be abused by attackers in order to achieve a variety of tactical objectives including execution, persistence, initial access, and more. RPC proxies may be used to collect and store RPC traffic. RPCs can occur over network sockets or named pipes. Analytics look for unauthorized behavior such as: * Processes being launched or scheduled remotely * System configurations being changed remotely * Unauthorized file read activity Example RPC Protocols: * DCE/RPC * CORBA * Open Network Computing Remote Procedure Call * D-Bus * XML-RPC * JSON-RPC * SOAP * Apache Thrift ## Considerations * RPC is widely used in enterprise environments, and significant data filtering may be required in large environments to enable analytic processing. * RPC traffic may occur over a pipe, or within a host over loopback interface, thus making network collection difficult.
synonym: RPC Protocol Analysis

Radio Modem
type: Class
subclass of: Modem
definition: A radio modem provides the means to send digital data wirelessly. Radio modems are used to communicate by direct broadcast satellite, WiFi, WiMax, mobile phones, GPS, Bluetooth and NFC. Modern telecommunications and data networks also make extensive use of radio modems where long distance data links are required. Such systems are an important part of the PSTN, and are also in common use for high-speed computer network links to outlying areas where fiber optic is not economical.

Random Forest
type: Class
subclass of: Bootstrap Aggregating
type: NamedIndividual
d3fend-id: D3A-RF
definition: Random Forest is a ML method that combines several other ML methods. At its core, Random Forest is an ensemble method of multiple bootstrapped decision trees filled with training data and random feature selection.
kb-article: ## References Random forest. Wikipedia. [Link](https://en.wikipedia.org/wiki/Random_forest).

Random Splits
type: Class
subclass of: Resampling Ensemble
type: NamedIndividual
d3fend-id: D3A-RS
definition: The dataset is repeatedly sampled with a random split of the data into train and test sets.
kb-article: ## References How to Create a Random Split Cross-Validation and Bagging Ensemble for Deep Learning in Keras."*Machine Learning Mastery*. [Link](https://machinelearningmastery.com/how-to-create-a-random-split-cross-validation-and-bagging-ensemble-for-deep-learning-in-keras/).

Range
type: Class
subclass of: Variability
type: NamedIndividual
d3fend-id: D3A-RAN
definition: The range of a set of data is the difference between the largest and smallest value.
kb-article: ## References Wikipedia. (n.d.). Range (statistics). [Link](https://en.wikipedia.org/wiki/Range_(statistics))

Range Matching
type: Class
subclass of: Numeric Pattern Matching
type: NamedIndividual
d3fend-id: D3A-RM
definition: Numeric Range Matching determines if a value lies with an interval of values (i.e., within the range of values.)

Rank Correlation
type: Class
subclass of: Correlation
type: NamedIndividual
d3fend-id: D3A-RC
definition: A rank correlation is any of several statistics that measure an ordinal association-the relationship between rankings of different ordinal variables or different rankings of the same variable, where a "ranking" is the assignment of the ordering labels "first", "second", "third", etc. to different observations of a particular variable.
kb-article: Wikipedia. (n.d.). Rank correlation. [Link](https://en.wikipedia.org/wiki/Rank_correlation)

Raw Memory Access Function
type: Class
subclass of: Subroutine
subclass of: Restriction
  on property: accesses
  some values from: Memory Block
type: NamedIndividual
accesses: Memory Block
definition: A function which accesses raw memory, usually using memory addresses.

Read File
type: Class
subclass of: System Call
subclass of: Restriction
  on property: reads
  some values from: File
type: NamedIndividual
reads: File
definition: A program that needs to access data from a file stored in a file system uses the read system call. The file is identified by a file descriptor that is normally obtained from a previous call to open. This system call reads in data in bytes, the number of which is specified by the caller, from the file and stores then into a buffer supplied by the calling process.

Read Memory
type: Class
subclass of: System Call
subclass of: Restriction
  on property: reads
  some values from: Memory Block
type: NamedIndividual
reads: Memory Block

Reconnaissance Technique
type: Class
subclass of: ATTACK Enterprise Technique
subclass of: Offensive Technique
subclass of: Restriction
  on property: enables
  some values from: Reconnaissance
type: NamedIndividual
enables: Reconnaissance

Record
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: In computer science, a record (also called struct or compound data) is a basic data structure. A record is a collection of fields, possibly of different data types, typically in fixed number and sequence . The fields of a record may also be called members, particularly in object-oriented programming. Fields may also be called elements, though these risk confusion with the elements of a collection. A tuple may or may not be considered a record, and vice versa, depending on conventions and the specific programming language.

Recurrent Neural Network
type: Class
subclass of: Deep Neural Network Classification
type: NamedIndividual
d3fend-id: D3A-RNN
definition: Recurrent Nerual Networks (RNN) are a class of artificial neural networks where connections between nodes can create a cycle, allowing output from some nodes to affect subsequent input to the same nodes. This allows it to exhibit temporal dynamic behavior.
kb-article: ## References Wikipedia. (2021, September 7). Recurrent Neural Network. [Link](https://en.wikipedia.org/wiki/Recurrent_neural_network)

Reference Nullification
type: Class
subclass of: Source Code Hardening
subclass of: Restriction
  on property: hardens
  some values from: Memory Free Function
type: NamedIndividual
hardens: Memory Free Function
kb-reference: Reference-ReferenceNullification SecureSoftwareInc
d3fend-id: D3-RN
definition: Invalidating all pointers that reference a specific memory block, ensuring that the block cannot be accessed or modified after deallocation.
kb-article: ## How it Works Nullifying references to memory blocks makes those blocks no longer accessible. This is critical to prevent use-after-free errors. ## Considerations * If a memory block is freed, all other references to that block should be nullified. * This is particularly relevant when manually managing memory. * Note: This resource should not be considered a definitive or exhaustive coding guideline.

Regex Matching
type: Class
subclass of: Partial Matching
type: NamedIndividual
d3fend-id: D3A-RM
definition: Regular expression matching is type of partial string matching using a regular expression, which is a sequence of characters that specifies a match pattern in text.
kb-article: ## How it works A regular expression (shortened as regex or regexp) is a sequence of characters that specifies a match pattern in text. Usually such patterns are used by string-searching algorithms for "find" or "find and replace" operations on strings, or for input validation. ## Key Test Considerations - **External review of regular expressions**: Regular expressions used in rules should be reviewed by a independent developer SME. Regex testing and visualization tools may be used to aid this review. Back-tests for failure modes identified during the review shoud be developed. Regular expressions are easy to get wrong and may appear to work on limited tests; small mistakes can lead to unintended misses and matches.] - **Processing Performance Review**: Review of resource-intensive rules may be necessary if system performance degraded. Look for cases of “exponential backtracking” Some regexes are computationally expensive. ## References 1. Regular expression. (2023, June 1). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Regular_expression). 2. String-searching algorithm. (2023, April 8). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/String-searching_algorithm).
synonym: Regex
synonym: Regexp

Registry Key Deletion
type: Class
subclass of: Object Eviction
subclass of: Restriction
  on property: deletes
  some values from: Windows Registry Key
type: NamedIndividual
deletes: Windows Registry Key
kb-reference: Reference-CybersecurityIncidentandVulnerabilityResponsePlaybooks
d3fend-id: D3-RKD
definition: Delete a registry key.

Regression Analysis
type: Class
subclass of: Statistical Method
type: NamedIndividual
d3fend-id: D3A-RA
definition: Regression analysis is a set of statistical processes for estimating the relationships between a dependent variable (often called the 'outcome' or 'response' variable, or a 'label' in machine learning parlance) and one or more independent variables (often called 'predictors', 'covariates', 'explanatory variables' or 'features').
kb-article: ## References Wikipedia. (n.d.). Regression analysis. [Link](https://en.wikipedia.org/wiki/Regression_analysis)

Regression Analysis Learning
type: Class
subclass of: Supervised Learning
type: NamedIndividual
d3fend-id: D3A-RAL
definition: Regression is used to understand the relationship between dependent and independent variables which is then used to make projections, such as for sales revenue for a given business.
kb-article: ## References Supervised Learning. IBM. [Link](https://www.ibm.com/topics/supervised-learning).

Reinforcement Learning
type: Class
subclass of: Machine Learning
type: NamedIndividual
d3fend-id: D3A-RL
definition: Reinforcement Learning is a subjugate technique of machine learning that uses feedback to reinforce good or valid rules and lessen the reliance of bad or ineffective rules
kb-article: ## References Reinforcement learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Reinforcement_learning).

Reissue Credential
type: Class
subclass of: Restore Access
subclass of: Restriction
  on property: restores
  some values from: Credential
type: NamedIndividual
kb-reference: Reference-CybersecurityIncidentandVulnerabilityResponsePlaybooks
restores: Credential
d3fend-id: D3-RIC
definition: Issue a new credential to a user which supercedes their old credential.

Relational-based Transfer Learning
type: Class
subclass of: Homogenous Transfer Learning
type: NamedIndividual
d3fend-id: D3A-RBTL
definition: Relational-based Transfer Learning is a subfield of machine learning where knowledge and patterns learned from one domain, characterized by relational and structured data, are transferred to enhance the learning of another related domain. This approach leverages shared concepts, relations, and structures across domains, taking advantage of the rich semantic knowledge within relational data to improve learning performance in the target task.
kb-article: ## References V7 Labs. (n.d.). Transfer Learning Guide. [Link](https://www.v7labs.com/blog/transfer-learning-guide#:~:text=Relational%2Dbased%20transfer%20learning%20approaches,domain%20to%20the%20target%20domain).

Relay Pattern Analysis
type: Class
subclass of: Network Traffic Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Outbound Internet Network Traffic
type: NamedIndividual
analyzes: Outbound Internet Network Traffic
kb-reference: Reference-MaliciousRelayDetectionOnNetworks VECTRANETWORKSInc
d3fend-id: D3-RPA
definition: The detection of an internal host relaying traffic between the internal network and the external network.
kb-article: ## How it works A relay may use a variety of proxying, forwarding, or routing technologies to bridge a protected network with an external network. A defensive analytic to detect a relay network may compare the network sessions among multiple hosts. Hosts which have nearly similar network statistics may be part of a relay network. The statistics may include number of bytes sent to and from, time of session initiation, packet size, or packet arrival time data. ## Considerations Complex intranet VPNs or routing encapsulation may affect the detection analytics. In addition, unwanted packets might not be forwarded, and additional packets may be added at the relay, further complicating detection.
synonym: Relay Network Detection

Remote Authentication Service
type: Class
subclass of: Authentication Service
subclass of: Network Service
definition: A remote authentication service provides for the authentication of a user across a network (i.e., remotely).

Remote Authorization Service
type: Class
subclass of: Authorization Service
definition: A remote authorization service provides for the authorization of a user across a network (i.e., remotely).

Remote Command
type: Class
subclass of: Command
definition: A remote command is a command sent from one computer to another to be executed on the remote computer. One example of this, is through a command-line interface (CLI) like using Invoke-Command from PowerShell or a command sent through an ssh session. This class generalizes to all means of sending a command through an established protocol to control capabilities on a remote computer.

Remote Database Query
type: Class
subclass of: Database Query
subclass of: Remote Command
definition: A remote query session enabling a user to make an SQL, SPARQL, or similar query over the network from one host to another.

Remote File Access Mediation
type: Class
subclass of: Network Resource Access Mediation
subclass of: Restriction
  on property: isolates
  some values from: File
type: NamedIndividual
isolates: File
kb-reference: Reference-NIST-Special-Publication-800-53-Revision-5
d3fend-id: D3-RFAM
definition: Remote file access mediation is the process of managing and securing access to file systems over a network to ensure that only authorized users or processes can interact with remote files.
kb-article: ## How it works Remote File Access Mediation focuses on controlling how users or processes access file systems from remote locations. This involves ensuring secure connections, often through protocols like SFTP or SMB, and enforcing permissions to prevent unauthorized access or data breaches. Examples of enforcement areas include accessing shared drives or cloud storage from remote offices or home networks.
synonym: File Share Access Mediation

Remote Login Session
type: Class
subclass of: Network Session
definition: A remote login session is a login session where a client has logged in from their local host machine to a server via a network.

Remote Procedure Call
type: Class
subclass of: Remote Command
definition: In distributed computing a remote procedure call (RPC) is when a computer program causes a procedure (subroutine) to execute in another address space (commonly on another computer on a shared network), which is coded as if it were a normal (local) procedure call, without the programmer explicitly coding the details for the remote interaction. That is, the programmer writes essentially the same code whether the subroutine is local to the executing program, or remote. This is a form of client-server interaction (caller is client, executor is server), typically implemented via a request-response message-passing system. The object-oriented programming analog is remote method invocation (RMI). The RPC model implies a level of location transparency.

Remote Resource
type: Class
subclass of: Resource
definition: In computing, a remote resource is a computer resource made available from one host to other hosts on a computer network. It is a device or piece of information on a computer that can be remotely accessed from another computer, typically via a local area network or an enterprise intranet.

Remote Session
type: Class
subclass of: Network Session
type: NamedIndividual
definition: A remote login session is a login session where a client has logged in from their local host machine to a server via a network.

Remote Terminal Session
type: Class
subclass of: Network Session
definition: A remote terminal session is a session that provides a user access from one host to another host via a terminal.

Remote Terminal Session Detection
type: Class
subclass of: Network Traffic Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Network Traffic
type: NamedIndividual
analyzes: Network Traffic
kb-reference: Reference-MethodAndSystemForDetectingExternalControlOfCompromisedHosts VECTRANETWORKSInc
kb-reference: Reference-RDPConnectionDetection MITRE
kb-reference: Reference-RemoteDesktopLogon MITRE
d3fend-id: D3-RTSD
definition: Detection of an unauthorized remote live terminal console session by examining network traffic to a network host.
kb-article: ## How it works An external attacker takes remote control of a host inside a company or organization's network and manually directs offensive techniques. Nonstandard terminal sessions and abnormal behaviors are analyzed in this technique. Abnormal behavior detection includes analysis of user input patterns in the real-time session, keyboard output and packet inspection. ### Network Traffic Inspection Network traffic from internal hosts is the main concern and focus for the traffic inspection. The network traffic is collected into inspection groups. The groups of traffic are assembled into distinct pair flows (outbound/inbound) and the pair flows are further divided into sessions. Only sessions originated inside of the network are considered for the inspection. Traffic inspection includes analysis to determine if a human is involved in the session exchanges. Time-based statistics are captured for each session being analyzed by the detection engine. ### Algorithm Analysis Description Analysis algorithms look for patterns in the network traffic captured from the session data. A detection engine groups the session traffic data, between the hosts, into rapid exchange instances. Analysis of rapid exchange traffic patterns can lead to the discovery of abnormal behavior which is indicative of a compromised internal host. The analysis algorithms look for patterns in the traffic which correlate to known activity (e.g., relay attacks, bot activity, bitcoin mining). Some metrics used during inspection include the following. * Number of rapid-exchange instances * Time interval between packets * Fixed cadence of traffic * Rhythm and direction of the initiation of instances * Volume of data flowing from internal to external controlling host * Data transfer characteristics * Variability in length of silent periods ## Considerations * Full packet capture is required which can be process intensive to analyze * Attackers that move low and slow may blend in with existing traffic result…

Removable Media Device
type: Class
subclass of: Hardware Device
type: NamedIndividual
definition: A removable media device is a hardware device used for computer storage and that is designed to be inserted and removed from the system. It is distinct from other removable media in that all the hardware required to read the data are built into the device. So USB flash drives and external hard drives are removable media devices, whereas tapes and disks are not, as they require additional hardware to perform read/write operations.

Remove User from Group Event
type: Class
subclass of: Group Management Event
definition: An event where a user is removed from a group, revoking the permissions and privileges associated with the group from the user.

Repository
type: Class
subclass of: Digital Information Bearer
definition: A centralized digital storage location where code, files, and related resources are systematically organized, managed, and maintained.

Resampling Ensemble
type: Class
subclass of: Ensemble Learning
type: NamedIndividual
d3fend-id: D3A-RE
definition: In the method, the small classes are oversampled and large classes are undersampled. The resampling scale is determined by the ratio of the min class number and max class number. And multiple machine learning methods are selected to construct the ensemble
kb-article: ## References Ensemble learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Ensemble_learning). Torgo, L. (2014). A resampling ensemble algorithm for improved accuracy. *Neurocomputing*, 134, 55-66. [Link](https://www.sciencedirect.com/science/article/pii/S0925231214007644#:~:text=A%20resampling%20ensemble%20algorithm%20is,and%20undersampling%20are%20empirically%20analyzed).

Residual Neural Network
type: Class
subclass of: Convolutional Neural Network
type: NamedIndividual
d3fend-id: D3A-RNN
definition: A residual neural network (ResNet) is an artificial neural network (ANN). It is a gateless or open-gated variant of the HighwayNet, the first working very deep feedforward neural network with hundreds of layers, much deeper than previous neural networks.
kb-article: ## References Wikipedia contributors. (2021, August 23). Residual neural network. In Wikipedia, The Free Encyclopedia. [Link](https://en.wikipedia.org/wiki/Residual_neural_network)

Resource
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: In computing, a system resource, or simply resource, is any physical or virtual component of limited availability within a computer system. Every device connected to a computer system is a resource. Every internal system component is a resource. Virtual system resources include files (concretely file handles), network connections (concretely network sockets), and memory areas. Managing resources is referred to as resource management, and includes both preventing resource leaks (releasing a resource when a process has finished using it) and dealing with resource contention (when multiple processes wish to access a limited resource).

Resource Access
type: Class
subclass of: User Action
type: NamedIndividual
definition: Ephemeral digital artifact comprising a request of a resource and any response from that resource.

Resource Access Pattern Analysis
type: Class
subclass of: User Behavior Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Authentication
subclass of: Restriction
  on property: analyzes
  some values from: Authorization
type: NamedIndividual
analyzes: Authentication
analyzes: Authorization
kb-reference: Reference-HostIntrusionPreventionSystemUsingSoftwareAndUserBehaviorAnalysis SophosLtd
kb-reference: Reference-MethodAndApparatusForNetworkFraudDetectionAndRemediationThroughAnalytics IdaptiveLLC
kb-reference: Reference-ModelingUserAccessToComputerResources DaedalusGroupLLC
kb-reference: Reference-SystemAndMethodThereofForIdentifyingAndRespondingToSecurityIncidentsBasedOnPreemptiveForensics PaloAltoNetworksInc
kb-reference: Reference-System,Method,AndComputerProgramProductForDetectingAndAssessingSecurityRisksInANetwork ExabeamInc
d3fend-id: D3-RAPA
definition: Analyzing the resources accessed by a user to identify unauthorized activity.
kb-article: ## How it works This technique analyzes a user's resource accesses by comparing the user's recent activity against a baseline activity model. Major differences between the current activity and the baseline model might indicate unauthorized activity if they are severe enough. ## Considerations * Potential for false positives from anomalies that are not associated with malicious activity. * Attackers that move low and slow may not differentiate their resource access activity behavior enough to trigger an alert.

Resource Development Technique
type: Class
subclass of: ATTACK Enterprise Technique
subclass of: Offensive Technique
subclass of: Restriction
  on property: enables
  some values from: Resource Development
type: NamedIndividual
enables: Resource Development

Resource Fork
type: Class
subclass of: File Section
type: NamedIndividual
definition: The resource fork is a fork or section of a file on Apple's classic Mac OS operating system, which was also carried over to the modern macOS for compatibility, used to store structured data along with the unstructured data stored within the data fork.

Restoration Event
type: Class
subclass of: Security Event
type: NamedIndividual
related: Restore
definition: An event representing actions to return a compromised system or resource to a trusted operational state, such as through backup restoration, system reinstallation, or repair.

Restore
type: Class
subclass of: Defensive Tactic
type: NamedIndividual
type: Defensive Tactic
definition: The restore tactic is used to return the system to a better state.
display-order: 5
display-priority: 0

Restore Access
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Restore
type: NamedIndividual
enables: Restore
kb-reference: Reference-CybersecurityIncidentandVulnerabilityResponsePlaybooks
d3fend-id: D3-RA
definition: Restoring an entity's access to resources.

Restore Configuration
type: Class
subclass of: Restore Object
subclass of: Restriction
  on property: restores
  some values from: Configuration Resource
type: NamedIndividual
kb-reference: Reference-CybersecurityIncidentandVulnerabilityResponsePlaybooks
restores: Configuration Resource
d3fend-id: D3-RC
definition: Restoring an software configuration.

Restore Database
type: Class
subclass of: Restore Object
subclass of: Restriction
  on property: restores
  some values from: Database
type: NamedIndividual
kb-reference: Reference-CybersecurityIncidentandVulnerabilityResponsePlaybooks
restores: Database
d3fend-id: D3-RD
definition: Restoring the data in a database.

Restore Disk Image
type: Class
subclass of: Restore Object
type: NamedIndividual
kb-reference: Reference-CybersecurityIncidentandVulnerabilityResponsePlaybooks
d3fend-id: D3-RDI
definition: Restoring a previously captured disk image a hard drive.

Restore Email
type: Class
subclass of: Restore File
subclass of: Restriction
  on property: restores
  some values from: Email
type: NamedIndividual
kb-reference: Reference-CybersecurityIncidentandVulnerabilityResponsePlaybooks
restores: Email
d3fend-id: D3-RE
definition: Restoring an email for an entity to access.

Restore File
type: Class
subclass of: Restore Object
subclass of: Restriction
  on property: restores
  some values from: File
type: NamedIndividual
kb-reference: Reference-CybersecurityIncidentandVulnerabilityResponsePlaybooks
restores: File
d3fend-id: D3-RF
definition: Restoring a file for an entity to access.

Restore Network Access
type: Class
subclass of: Restore Access
subclass of: Restriction
  on property: restores
  some values from: Host
type: NamedIndividual
kb-reference: Reference-CybersecurityIncidentandVulnerabilityResponsePlaybooks
restores: Host
d3fend-id: D3-RNA
definition: Restoring a entity's access to a computer network.

Restore Object
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Restore
type: NamedIndividual
enables: Restore
d3fend-id: D3-RO
definition: Restoring an object for an entity to access. This is the broadest class for object restoral.

Restore Software
type: Class
subclass of: Restore Object
subclass of: Restriction
  on property: restores
  some values from: Software
type: NamedIndividual
kb-reference: Reference-CybersecurityIncidentandVulnerabilityResponsePlaybooks
restores: Software
d3fend-id: D3-RS
definition: Restoring software to a host.

Restore User Account Access
type: Class
subclass of: Restore Access
subclass of: Restriction
  on property: restores
  some values from: User Account
type: NamedIndividual
kb-reference: Reference-CybersecurityIncidentandVulnerabilityResponsePlaybooks
restores: User Account
d3fend-id: D3-RUAA
definition: Restoring a user account's access to resources.

Resume Process
type: Class
subclass of: System Call
subclass of: Restriction
  on property: resumes
  some values from: Process
type: NamedIndividual
resumes: Process

Resume Thread
type: Class
subclass of: System Call
subclass of: Restriction
  on property: resumes
  some values from: Thread
type: NamedIndividual
resumes: Thread

Reverse Proxy Server
type: Class
subclass of: Proxy Server
definition: In computer networks, a reverse proxy is a type of proxy server that retrieves resources on behalf of a client from one or more servers. These resources are then returned to the client, appearing as if they originated from the proxy server itself. Unlike a forward proxy, which is an intermediary for its associated clients to contact any server, a reverse proxy is an intermediary for its associated servers to be contacted by any client. In other words, a proxy acts on behalf of the client(s), while a reverse proxy acts on behalf of the server(s); a reverse proxy is usually an internal-facing proxy used as a 'front-end' to control and protect access to a server on a private network.

Reverse Resolution IP Denylisting
type: Class
subclass of: DNS Denylisting
subclass of: Restriction
  on property: blocks
  some values from: Outbound Internet DNS Lookup Traffic
type: NamedIndividual
blocks: Outbound Internet DNS Lookup Traffic
kb-reference: Reference-UseDNSPolicyForApplyingFiltersOnDNSQueries
d3fend-id: D3-RRID
definition: Blocking a reverse lookup based on the query's IP address value.
kb-article: ## How it works This technique prevents a client from learning domains deemed to be potentially malicious, which would have been delivered via reverse resolution responses over the DNS protocol. Queries for reverse resolution requests (that is, requests where IP(s) are sent and a domain is returned) are collected, and the IP address(es) included in the query are examined. If the IP address(es) are in a range included in the blacklist, then the query is dropped. ## Considerations - The blacklist will have to be maintained and will need to be kept up to date with identified maintenance cycles to ensure lists are not stale. - DNS query traffic can be transmitted over many different protocols, which presents a challenge to implementing methods to extract all DNS query IP address value(s). - DNS has historically used UDP port 53, with TCP port 53 instead used for responses over 512 bytes or after a lack of response over UDP. - Usage of new protocols to provide confidentiality for DNS traffic, such as DoH (DNS over HTTPS) and DoT (DNS over TLS), complicates collection of the IP address(es) in DNS queries. These protocols have often been enabled in browser settings transparently after a browser update, with DNS queries proxied over one of these cryptographic protocols through a specified host.
synonym: Reverse Resolution IP Blacklisting

Revoke Privileges from Group Event
type: Class
subclass of: Group Management Event
definition: An event where specific privileges or rights are removed from a group, restricting its members from performing actions or accessing resources previously allowed by those privileges.

Router
type: Class
subclass of: Computer Network Node
definition: A router is a networking device that forwards data packets between computer networks. Routers perform the traffic directing functions on the Internet. Data sent through the internet, such as a web page or email, is in the form of data packets. A packet is typically forwarded from one router to another router through the networks that constitute an internetwork (e.g. the Internet) until it reaches its destination node.

Routing Access Mediation
type: Class
subclass of: Network Access Mediation
subclass of: Restriction
  on property: isolates
  some values from: Network
type: NamedIndividual
isolates: Network
kb-reference: Reference-WhatIsNetworkAccessControl
d3fend-id: D3-RAM
definition: Routing access mediation is a network security approach that manages and controls access at the network layer using VPNs, tunneling protocols, firewall rules, and traffic inspection to ensure secure and efficient data routing.
kb-article: ## How it works Routing Access Mediation is a network security strategy focused on managing and controlling access at the network layer. It includes the use of VPNs for secure remote access, tunneling protocols for encapsulating data, firewall rules for filtering traffic, and advanced inspection techniques like Cisco's Context-Based Access Control (CBAC) to monitor and regulate data flow. This approach ensures secure and efficient routing of data across networks, protecting against unauthorized access and enhancing overall network security.

SARSA
type: Class
subclass of: Model-free Reinforcement Learning
type: NamedIndividual
d3fend-id: D3A-SAR
definition: State-action-reward-state-action (SARSA) is an algorithm for learning a Markov decision process policy, used in the reinforcement learning area of machine learning.
kb-article: ## References State-action-reward-state-action. Wikipedia. [Link](https://en.wikipedia.org/wiki/State%E2%80%93action%E2%80%93reward%E2%80%93state%E2%80%93action).

SMB Event
type: Class
subclass of: Application Layer Event
subclass of: TCP Event
subclass of: Restriction
  on property: has-participant
  some values from: File Transfer Network Traffic
definition: An event involving the Server Message Block (SMB) protocol, a network file sharing protocol that allows client-server communication for accessing files, printers, and other shared network resources. SMB supports both transactional file operations and communication over reliable transport layers.

SMB File Create Event
type: Class
subclass of: SMB Event
definition: An event where a file is created if it does not already exist, failing if the file is already present. This operation strictly enforces new file creation.

SMB File Open Event
type: Class
subclass of: SMB Event
definition: An event where a file is opened if it exists, failing otherwise. This operation is used to access or query the existing file.

SMB File Open If Event
type: Class
subclass of: SMB Event
definition: An event where a file is opened if it exists, or created if it does not. This operation merges file creation and access behavior.

SMB File Overwrite Event
type: Class
subclass of: SMB Event
definition: An event where a file is opened and truncated if it exists, failing if the file does not already exist. This operation is destructive and focuses on replacing the file's contents.

SMB File Overwrite If Event
type: Class
subclass of: SMB Event
definition: An event where a file is opened and truncated if it exists, or created otherwise. This operation combines destructive overwrite and creation behaviors.

SMB File Supersede Event
type: Class
subclass of: SMB Event
definition: An event where a file is overwritten if it exists or created if it does not. This operation combines file creation and modification semantics.

SPARTA Thing
type: Class
subclass of: External Threat Model Thing

SSH Connection Close Event
type: Class
subclass of: Network Connection Close Event
subclass of: SSH Event
definition: An event indicating the termination of an SSH connection, signaling the end of a secure session.

SSH Connection Fail Event
type: Class
subclass of: Network Connection Fail Event
subclass of: SSH Event
definition: An event indicating a failure to establish an SSH connection, often due to issues such as authentication errors, network timeouts, or server unavailability.

SSH Connection Open Event
type: Class
subclass of: Network Connection Open Event
subclass of: SSH Event
definition: An event indicating the successful establishment of an SSH connection between a client and a server, marking the initiation of a secure session.

SSH Connection Refuse Event
type: Class
subclass of: Network Connection Refuse Event
subclass of: SSH Event
definition: An event indicating that an SSH connection attempt was refused, typically due to server-side restrictions or closed ports.

SSH Connection Reset Event
type: Class
subclass of: Network Connection Reset Event
subclass of: SSH Event
definition: An event indicating the abrupt termination of an SSH connection due to protocol errors, network disruptions, or administrative actions.

SSH Event
type: Class
subclass of: Application Layer Event
subclass of: TCP Event
subclass of: Restriction
  on property: has-participant
  some values from: SSH Session
definition: An event involving the Secure Shell (SSH) protocol, a cryptographic network protocol designed to provide secure remote login, command execution, and data transfer. SSH facilitates encrypted communication between clients and servers, ensuring confidentiality, integrity, and authenticity.

SSH Listen Event
type: Class
subclass of: Network Connection Listen Event
subclass of: SSH Event
definition: An event indicating that an SSH server has started listening for incoming connection requests, enabling potential clients to initiate secure sessions.

SSH Session
type: Class
subclass of: Remote Session
type: NamedIndividual
definition: A Secure Shell Protocol (SSH) session is a session over a secure channel established using SSH to connect a client to a server and establish the remote session.

Save Registers
type: Class
subclass of: System Call
subclass of: Restriction
  on property: copies
  some values from: Processor Register
type: NamedIndividual
copies: Processor Register

Saved Instruction Pointer
type: Class
subclass of: Pointer
subclass of: Stack Component
definition: A saved instruction pointer points to the instruction that generated an exception (trap or fault).

Scheduled Job
type: Class
subclass of: Operating System Process
subclass of: Restriction
  on property: contained-by
  some values from: Job Schedule
subclass of: Restriction
  on property: created-by
  some values from: Job Scheduler Software
subclass of: Restriction
  on property: modified-by
  some values from: Job Scheduler Software
type: NamedIndividual
contained-by: Job Schedule
created-by: Job Scheduler Software
modified-by: Job Scheduler Software
definition: A task scheduler process is an operating system process that executes scheduled tasks (time-scheduling in the sense of wall clock time; not operating system scheduling of processes for multitasking).
synonym: Scheduled Task
synonym: Task Scheduler Process

Scheduled Job Analysis
type: Class
subclass of: Operating System Monitoring
subclass of: Restriction
  on property: analyzes
  some values from: Job Schedule
type: NamedIndividual
analyzes: Job Schedule
kb-reference: Reference-ExecutionWithAT MITRE
kb-reference: Reference-ExecutionWithSchtasks MITRE
kb-reference: Reference-PreventingExecutionOfTaskScheduledMalware McAfeeLLC
d3fend-id: D3-SJA
definition: Analysis of source files, processes, destination files, or destination servers associated with a scheduled job to detect unauthorized use of job scheduling.
kb-article: ## How it works Scheduled job execution can be utilized by adversaries for the purpose of persistence, conducting remote execution, or gaining privileges. Details of a scheduled job such as associated source files, processes, destination files, or destination servers are first identified and analyzed and then compared against an anti-malware signature database, whitelist, or reputation server. For example, a file associated with a scheduled job to be executed at a specified time or a remote server that is accessed as part of a scheduled task is compared against an anti-malware signature database, whitelist, or reputation server, and if a match is found, execution is denied and an alert is generated. In addition to traditional scheduled jobs, triggers can be set to execute a specific command after detecting a specific event in the system, such as with WMI Event Subscriptions in Windows. ## Considerations Jobs can be scheduled in many different and sometimes creative ways through operating system capabilities.
synonym: Scheduled Job Execution

Scheduled Job Creation Event
type: Class
subclass of: Scheduled Job Event
definition: An event representing the addition of a new task to the system's scheduler, defining its execution criteria and associated actions.

Scheduled Job Deletion Event
type: Class
subclass of: Scheduled Job Event
definition: An event marking the removal of a scheduled task from the system, terminating its execution schedule.

Scheduled Job Disable Event
type: Class
subclass of: Scheduled Job Event
definition: An event where a scheduled task is deactivated, preventing further execution until re-enabled.

Scheduled Job Enable Event
type: Class
subclass of: Scheduled Job Event
definition: An event where a scheduled task is activated, allowing it to execute according to its defined parameters.

Scheduled Job Event
type: Class
subclass of: Digital Event
subclass of: Restriction
  on property: has-participant
  some values from: Scheduled Job
definition: An event capturing the lifecycle or management of scheduled tasks within a system, including creation, modification, execution, or removal.

Scheduled Job Start Event
type: Class
subclass of: Scheduled Job Event
definition: An event indicating the execution of a scheduled task, triggered either automatically by the scheduler or manually by a user.

Scheduled Job Update Event
type: Class
subclass of: Scheduled Job Event
definition: An event where an existing scheduled task is updated, altering parameters such as timing, conditions, or actions.

Scheduling
type: Class
subclass of: Planning

Script Application Process
type: Class
subclass of: Application Process
subclass of: Restriction
  on property: interprets
  some values from: Executable Script
type: NamedIndividual
interprets: Executable Script
definition: A script application process is an application process interpreting an executable script.
alternative label: Script Process

Script Execution Analysis
type: Class
subclass of: Process Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Script Application Process
type: NamedIndividual
analyzes: Script Application Process
kb-reference: Reference-DetectingScript-basedMalware CrowdstrikeInc
d3fend-id: D3-SEA
definition: Analyzing the execution of a script to detect unauthorized user activity.
kb-article: ## How it works Software installed on the host system hooks into a scripting engine to intercept commands before they are executed and block commands if they are determined to be harmful. Pattern matching is used to identify unauthorized commands or in the case of script files, a hash of the file is compared against hashes of known unauthorized script files. ## Considerations List of known unauthorized script files or regular expression patterns must be kept up to date to ensure detection of new threats.

Second-stage Boot Loader
type: Class
subclass of: Boot Loader
definition: An optional, often feature rich, second stage set of routines run in order to load the operating system.

Secondary Storage
type: Class
subclass of: Hardware Device
subclass of: Storage
type: NamedIndividual
definition: Secondary memory (storage, hard disk) is the computer component holding information that does not need to be accessed quickly and that needs to be retained long-term.

Security Event
type: Class
subclass of: Digital Event
subclass of: Restriction
  on property: caused-by
  some values from: Defensive Action
definition: An event describing occurrences related to cybersecurity, including detection, remediation, or enforcement actions. Security events provide critical insights into the state, behavior, and resilience of digital systems.

Security Token
type: Class
subclass of: Hardware Device
subclass of: Restriction
  on property: contains
  some values from: Access Token
type: NamedIndividual
contains: Access Token
definition: Security tokens are peripheral devices used to prove one's identity electronically (as in the case of a customer trying to access their bank account). The token is used in addition to or in place of a password to prove that the customer is who they claim to be. The token acts like an electronic key to access something.

Segment Address Offset Randomization
type: Class
subclass of: Application Hardening
subclass of: Restriction
  on property: obfuscates
  some values from: Process Segment
type: NamedIndividual
kb-reference: Reference-DYNAMICBASE UseAddressSpaceLayoutRandomization MicrosoftDocs
kb-reference: Reference-HowASLRProtectsLinuxSystemsFromBufferOverflowAttacks NetworkWorld
obfuscates: Process Segment
d3fend-id: D3-SAOR
definition: Randomizing the base (start) address of one or more segments of memory during the initialization of a process.
kb-article: ## How it works Many application exploits rely on an attacker specifying a location in memory, which points to data or code used by the attacker. If the addresses are changed each time the program is run, then it becomes more difficult for the attacker to determine the location that will contain the code they wish to run. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as "rebasing." Just as not all code is built for participation in ASLR, not all modules can be rebased; instead, modules must indicate whether they implement support for rebasing. Such information to relocate the executable is typically stored in the ".reloc" segment -- each of the addresses pointed to in this segment has its address increased by the amount of the offset. (An alternative method for relocation would be to add an amount to a global variable each time -- leading to less overhead in the module load, but more for each access. Still another implementation could instead contain code to deference each changeable memory location on the fly, so that each of the references do not need to be updated. ## Considerations As the offset for each segment is constant, it is possible to guess at the value of the address given the address of another variable. Alternatively, memory pointers may be kept around, which contain the address of another variable. Another bypass technique is known as an "egg hunt," whereby the attacker searches for a rather unique piece of the data or code in memory to determine its likely address. The program needs to store these addresses for the functions somewhere. In Linux, the PLT contains a "trampoline" to these addresses. If an attacker desires to jump to the start of an existing function, they can jump directly to the trampoline anyway, and may have the opportunity to provide their own stack frame to the function with a write to the stack. If they overwrite a saved stack pointer which is loaded …
synonym: ASLR
synonym: Address Space Layout Randomization

Self-organizing Map
type: Class
subclass of: ANN-based Clustering
type: NamedIndividual
d3fend-id: D3A-SOM
definition: A Self-Organizing Map (SOM) is a unsupervised learning model in Artificial Neural Network where the feature maps are the generated two-dimensional discretized form of an input space during the model training (based on competitive learning)
kb-article: ## References GeeksforGeeks. (n.d.). ANN - Self Organizing Neural Network (SONN). [Link](https://www.geeksforgeeks.org/ann-self-organizing-neural-network-sonn/)

Semi-Supervised Learning
type: Class
subclass of: Machine Learning
type: NamedIndividual
d3fend-id: D3A-SSL
definition: Semi-supervised learning is a branch of machine learning that combines a small amount of labeled data with a large amount of unlabeled data during training.
kb-article: ## References Semi-Supervised Learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Semi-Supervised_Learning).

Semi-supervised Boosting
type: Class
subclass of: Semi-supervised Wrapper Method
type: NamedIndividual
d3fend-id: D3A-SSB
definition: Boosting methods can be readily extended to the semi-supervised setting, by introducing pseudo-labeled data after each learning step; which gives rise to the idea of semi-supervised boosting methods. The pseudo-labeling approach of self- training and co-training can be easily extended to boosting methods. Several boosting methods such as SSMBoost, ASSEMBLE, SemiBoost, RegBoost, etc can be found which can be applied for utilizing unlabeled datasets for supervised classifiers.
kb-article: ## References Jashish Shrestha. (n.d.). Beginner's Guide to Semi-Supervised Learning. [Link](http://jashish.com.np/blog/posts/beginners-guide-to-semi-supervised-learning/)

Semi-supervised Cluster-then-label
type: Class
subclass of: Unsupervised Preprocessing
type: NamedIndividual
d3fend-id: D3A-SSCTL
definition: Pre-training methods are aimed to guide the parameters of a network towards interesting regions in model space using unlabeled data, before fine-tuning the parameters with the labeled data.
kb-article: ## References Jashish Shrestha. (n.d.). Beginner's Guide to Semi-Supervised Learning. [Link](http://jashish.com.np/blog/posts/beginners-guide-to-semi-supervised-learning/)

Semi-supervised Co-training
type: Class
subclass of: Semi-supervised Wrapper Method
type: NamedIndividual
d3fend-id: D3A-SSCT
definition: Multi-view co-training involves training the classifiers in completely different views of training data. On the other hand, single-view co-training methods are generally applied as ensemble methods.
kb-article: ## References Jashish Shrestha. (n.d.). Beginner's Guide to Semi-Supervised Learning. [Link](http://jashish.com.np/blog/posts/beginners-guide-to-semi-supervised-learning/)

Semi-supervised Feature Extraction
type: Class
subclass of: Unsupervised Preprocessing
type: NamedIndividual
d3fend-id: D3A-SSFE
definition: Feature extraction refers to reducing the number of dimensions in a data point so that it is computationally feasible and effective to learn a model.
kb-article: ## References Jashish Shrestha. (n.d.). Beginner's Guide to Semi-Supervised Learning. [Link](http://jashish.com.np/blog/posts/beginners-guide-to-semi-supervised-learning/)

Semi-supervised Generative Model Learning
type: Class
subclass of: Intrinsically Semi-supervised Learning
type: NamedIndividual
d3fend-id: D3A-SSGML
definition: A Semi Supervised Machine Learning model which assume that the distributions take some particular form p(x|y,theta) parameterized by the vector. If these assumptions are incorrect, the unlabeled data may actually decrease the accuracy of the solution relative to what would have been obtained from labeled data alone. However, if the assumptions are correct, then the unlabeled data necessarily improves performance.
kb-article: ## References Weak supervision. Wikipedia. [Link](https://en.wikipedia.org/wiki/Weak_supervision#Generative_models).

Semi-supervised Inductive Learning
type: Class
subclass of: Semi-Supervised Learning
type: NamedIndividual
d3fend-id: D3A-SSIL
definition: The goal of inductive learning is to infer the correct mapping from X to Y
kb-article: ## References Semi-Supervised Learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Semi-Supervised_Learning#Semi-supervised_learning). Zhou, D., & Li, M. (2005). Semi-supervised learning by higher order regularization. In Proceedings of the 43rd Annual Meeting of the Association for Computational Linguistics (ACL) (pp. 1-9). [Link](https://www.cs.sfu.ca/~anoop/papers/pdf/semisup_naacl.pdf).

Semi-supervised Manifold Learning
type: Class
subclass of: Intrinsically Semi-supervised Learning
type: NamedIndividual
d3fend-id: D3A-SSML
definition: A version of Semi-Supervised Learning that applies the Manifold assumption that the data like approximately on a manifold of much lower dimension than the input space.
kb-article: ## References Weak supervision. Wikipedia. [Link](https://en.wikipedia.org/wiki/Weak_supervision#Generative_models).

Semi-supervised Pre-training
type: Class
subclass of: Unsupervised Preprocessing
type: NamedIndividual
d3fend-id: D3A-SSPT
definition: Pre-training methods are aimed to guide the parameters of a network towards interesting regions in model space using unlabeled data, before fine-tuning the parameters with the labeled data
kb-article: ## References Jashish Shrestha. (n.d.). Beginner's Guide to Semi-Supervised Learning. [Link](http://jashish.com.np/blog/posts/beginners-guide-to-semi-supervised-learning/)

Semi-supervised Self-training
type: Class
subclass of: Semi-supervised Wrapper Method
type: NamedIndividual
d3fend-id: D3A-SSST
definition: Self-training is the procedure in which a supervised method for classification or regression is modified it to work in a semi-supervised manner, taking advantage of labeled and unlabeled data
kb-article: ## References AltexSoft. (n.d.). Semi-Supervised Learning: A Technical Guide with Python Examples. [Link](https://www.altexsoft.com/blog/semi-supervised-learning/#:~:text=One%20of%20the%20simplest%20examples,of%20labeled%20and%20unlabeled%20data.)

Semi-supervised Transductive Learning
type: Class
subclass of: Semi-Supervised Learning
type: NamedIndividual
d3fend-id: D3A-SSTL
definition: The goal of transductive learning is to infer the correct labels for the given unlabeled data x_{l+1},... ,x_{l+u} only
kb-article: ## References Semi-Supervised Learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Semi-Supervised_Learning#Semi-supervised_learning). Zhou, D., & Li, M. (2005). Semi-supervised learning by higher order regularization. In Proceedings of the 43rd Annual Meeting of the Association for Computational Linguistics (ACL) (pp. 1-9). [Link](https://www.cs.sfu.ca/~anoop/papers/pdf/semisup_naacl.pdf).

Semi-supervised Wrapper Method
type: Class
subclass of: Semi-Supervised Learning
type: NamedIndividual
d3fend-id: D3A-SSWM
definition: The principle behind wrapper methods is that we train a model with labeled data and then generate pseudo-labels for the unlabeled data using the trained model iteratively.
kb-article: ## References Jashish, M. (n.d.). Beginner's Guide to Semi-Supervised Learning. Jashish Blog. [Link](http://jashish.com.np/blog/posts/beginners-guide-to-semi-supervised-learning/).

Sender MTA Reputation Analysis
type: Class
subclass of: Message Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Email
type: NamedIndividual
analyzes: Email
kb-reference: Reference-SystemsAndMethodsForDetectingAnd orHandlingTargetedAttacksInTheEmailChannel GraphusInc
d3fend-id: D3-SMRA
definition: Characterizing the reputation of mail transfer agents (MTA) to determine the security risk in emails.
kb-article: ## How it works The sender message transfer agent (MTA) trust rating can be considered an indicator of the level of security risk and/or a trust level associated with sender MTAs in an email header. The features considered in determining the trust rating may include: * Length of time MTA has interacted with the enterprise * Number of sender domains sending emails from the MTA * Number of recipients in the enterprise the MTA sends emails to * Number of emails received from this MTA * Number of email replies received from this MTA For example, higher values for the length of time an MTA has interacted with the enterprise, or number of emails received from an MTA can result in a higher trust rating. The trust rating categorizes the sender MTA as unrated, neutral, trusted, suspicious, or malicious. ## Considerations Legitimate emails from a sender MTA may receive a lower trust rating over time if the sender's domain gets spoofed and is used to send unauthorized emails.

Sender Reputation Analysis
type: Class
subclass of: Message Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Email
type: NamedIndividual
analyzes: Email
kb-reference: Reference-SystemsAndMethodsForDetectingAnd orHandlingTargetedAttacksInTheEmailChannel GraphusInc
d3fend-id: D3-SRA
definition: Ascertaining sender reputation based on information associated with a message (e.g. email/instant messaging).
kb-article: ## How it works Sender trust rating can be considered an indicator of the level of security risk and/or a trust level associated with a sender. The features considered in determining the trust rating include: * Length of time sender has sent emails to the enterprise * Number of recipients in the enterprise the sender interacts with * Sender vs. enterprise originated message ratio * Sender messages opened vs. not-opened ratio * Number of emails received from this sender * Number of emails replied to this sender * Number of emails from this sender not opened * Number of emails from this sender not opened that contain an attachment * Number of emails from this sender not opened that contain a URL * Number of emails sent to this sender * Number of email replies received from this sender. Higher values for the number of recipients the sender has interacted with or the number of emails received from the sender, for example, results in a higher trust rating. The trust rating can categorize the sender as unrated, neutral, trusted, suspicious, or malicious. ## Considerations Legitimate emails from a sender may receive a lower trust rating over time if the sender's domain gets spoofed and is used to send unauthorized emails.

Sensor
type: Class
subclass of: D3FEND Core
subclass of: Digital Information Bearer
definition: In the broadest definition, a sensor is a device, module, machine, or subsystem that detects events or changes in its environment and sends the information to other electronics, frequently a computer.

SeqGAN
type: Class
subclass of: Generative Adversarial Network
type: NamedIndividual
d3fend-id: D3A-SEQ
definition: Sequence Generation Framework (SeqGAN) models the data generator as a stochastic policy in reinforcement learning (RL), SeqGAN bypasses the generator differentiation problem by directly performing gradient policy update.
kb-article: ## References Yu, L., Zhang, W., Wang, J., & Yu, Y. (2017). SeqGAN: Sequence Generative Adversarial Nets with Policy Gradient. ArXiv preprint ArXiv:1609.05473. [Link](https://arxiv.org/abs/1609.05473)
synonym: Sequence GAN

Serialization Function
type: Class
subclass of: Subroutine
definition: A function which has an operation that serializes data.

Server
type: Class
subclass of: Host
subclass of: Restriction
  on property: manages
  some values from: Service Application Process
subclass of: Restriction
  on property: runs
  some values from: Service Application
type: NamedIndividual
manages: Service Application Process
runs: Service Application
definition: In computing, a server is a piece of computer hardware or software (computer program) that provides functionality for other programs or devices, called "clients". This architecture is called the client-server model. Servers can provide various functionalities, often called "services", such as sharing data or resources among multiple clients, or performing computation for a client. A single server can serve multiple clients, and a single client can use multiple servers. A client process may run on the same device or may connect over a network to a server on a different device. Typical servers are database servers, file servers, mail servers, print servers, web servers, game servers, and application servers.

Service Account
type: Class
subclass of: User Account
definition: A service account is a type of account used by an application or service to interact with the operating system.
synonym: System Account

Service Application
type: Class
subclass of: Application
type: NamedIndividual
definition: An application that provides a set of software functionalities so that multiple clients who can reuse the functionality, provided they are authorized for use of the service.

Service Application Process
type: Class
subclass of: Application Process
type: NamedIndividual

Service Binary Verification
type: Class
subclass of: System File Analysis
subclass of: Restriction
  on property: verifies
  some values from: Service Application
type: NamedIndividual
kb-reference: Reference-ServiceBinaryModifications MITRE
verifies: Service Application
d3fend-id: D3-SBV
definition: Analyzing changes in service binary files by comparing to a source of truth.
kb-article: ## How it works System service applications may originate from the operating system installation or third-party applications installed with administrative privileges. These services have an entry point of some executable file-- a binary or a script. Attackers sometimes modify these executables to launch their own code. Analyzing changes in these files may uncover unauthorized activity. ## Considerations * These files change for legitimate reasons when the system or software updates. * The source of truth must not be corrupted in order for this method to work.

Service Deletion Event
type: Class
subclass of: Application Deletion Event
subclass of: Service Event
definition: An event capturing the uninstallation or deregistration of a service application, ensuring it is no longer operational or available to clients.

Service Dependency
type: Class
subclass of: Dependency
type: NamedIndividual
definition: A service dependency indicates a service has an activity, agent, or another service which relies on it in order to be functional.

Service Dependency Mapping
type: Class
subclass of: System Mapping
subclass of: Restriction
  on property: maps
  some values from: Service Dependency
type: NamedIndividual
kb-reference: Reference-CatiaUAFPlugin
kb-reference: Reference-UnifiedArchitectureFrameworkUAF
maps: Service Dependency
d3fend-id: D3-SVCDM
definition: Service dependency mapping determines the services on which each given service relies.
kb-article: ## How it works The organization collects and models architectural information about the services and consumers of services and maps the dependencies between the services. ## Considerations * Architectural design artifacts and SMEs may need to be consulted to determine if dependencies are intended or otherwise essential. * Service dependencies for critical systems--those supporting critical organizational activities--should be prioritized for supply chain risk analysis. * Service dependencies in cloud or microservice architectures may be discovered using distributed tracing capabilities
synonym: Distributed Tracing

Service Disable Event
type: Class
subclass of: Application Disable Event
subclass of: Service Event
definition: An event capturing the deactivation of a service application, preventing it from being started or accessed until re-enabled.

Service Enable Event
type: Class
subclass of: Application Enable Event
subclass of: Service Event
definition: An event representing the activation of a service application, allowing it to start and provide its background or networked functionality.

Service Event
type: Class
subclass of: Application Event
subclass of: Restriction
  on property: has-participant
  some values from: Service Application
definition: An event capturing the operation, configuration, or lifecycle of a service application. Services are specialized applications designed to provide reusable functionality to clients, systems, or other applications, often operating in the background or across networks.

Service Installation Event
type: Class
subclass of: Application Installation Event
subclass of: Service Event
definition: An event representing the installation or registration of a service application within the system, enabling it to provide background or reusable functionality.

Service Provider
type: Class
subclass of: Provider

Service Restart Event
type: Class
subclass of: Application Restart Event
subclass of: Service Event
definition: An event describing the sequential stopping and starting of a service application to refresh its state, apply updates, or resolve operational issues.

Service Start Event
type: Class
subclass of: Application Start Event
subclass of: Service Event
definition: An event representing the initiation of a service application, transitioning it from an inactive state to an active state, enabling its background or networked operations.

Service Stop Event
type: Class
subclass of: Application Stop Event
subclass of: Service Event
definition: An event capturing the cessation of a service application’s operations, transitioning it to an inactive state while ceasing its functionality to clients or dependent systems.

Service Update Event
type: Class
subclass of: Application Update Event
subclass of: Service Event
definition: An event describing changes made to a service application, such as updates, reconfigurations, or patch installations, ensuring its continued availability and functionality.

Session
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: In computer science, in particular networking, a session is a semi-permanent interactive information interchange, also known as a dialogue, a conversation or a meeting, between two or more communicating devices, or between a computer and user (see Login session). A session is set up or established at a certain point in time, and then torn down at some later point. An established communication session may involve more than one message in each direction. A session is typically, but not always, stateful, meaning that at least one of the communicating parts needs to save information about the session history in order to be able to communicate, as opposed to stateless communication, where the communication consists of independent requests with responses.

Session Cookie
type: Class
subclass of: Credential
type: NamedIndividual
definition: A session cookie, also known as an in-memory cookie, transient cookie or non-persistent cookie, exists only in temporary memory while the user navigates the website. Web browsers normally delete session cookies when the user closes the browser. Unlike other cookies, session cookies do not have an expiration date assigned to them, which is how the browser knows to treat them as session cookies.
alternative label: In-memory Cookie
alternative label: Non-persistent Cookie
alternative label: Transient Cookie
alternative label: Web Session Cookie

Session Duration Analysis
type: Class
subclass of: User Behavior Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Authentication
subclass of: Restriction
  on property: analyzes
  some values from: Authorization
type: NamedIndividual
analyzes: Authentication
analyzes: Authorization
kb-reference: Reference-MethodAndApparatusForNetworkFraudDetectionAndRemediationThroughAnalytics IdaptiveLLC
kb-reference: Reference-System,Method,AndComputerProgramProductForDetectingAndAssessingSecurityRisksInANetwork ExabeamInc
d3fend-id: D3-SDA
definition: Analyzing the duration of user sessions in order to detect unauthorized activity.
kb-article: ## How it works Detecting unauthorized user sessions by comparing the duration of a user logon session with a baseline behavior model. The behavior model comprises historical user session duration times. Abnormalities between session duration and the behavior model may indicate suspicious activity. ## Considerations * Potential for false positives from anomalies that are not associated with malicious activity. * Attackers may not differentiate their session duration enough to trigger an alert.

Session Termination
type: Class
subclass of: Process Eviction
subclass of: Restriction
  on property: deletes
  some values from: Session
type: NamedIndividual
deletes: Session
kb-reference: Reference-NIST-Special-Publication-800-53A-Revision-5
d3fend-id: D3-ST
definition: Forcefully end all active sessions associated with compromised accounts or devices.
kb-article: Defined in NIST 800-53 as AC-12.

Session Token
type: Class
subclass of: Access Token
type: NamedIndividual
definition: In computer science, a session identifier, session ID or session token is a piece of data that is used in network communications (often over HTTPS) to identify a session, a series of related message exchanges.
kb-article: ## How it works Session identifiers become necessary in cases where the communications infrastructure uses a stateless protocol such as HTTP. For example, a buyer who visits a seller's website wants to collect a number of articles in a virtual shopping cart and then finalize the shopping by going to the site's checkout page. This typically involves an ongoing communication where several webpages are requested by the client and sent back to them by the server. In such a situation, it is vital to keep track of the current state of the shopper's cart, and a session ID is one way to achieve that goal.
synonym: Session ID
synonym: Session Identifier
synonym: Session Token

Set Registers
type: Class
subclass of: System Call
subclass of: Restriction
  on property: modifies
  some values from: Processor Register
type: NamedIndividual
modifies: Processor Register

Set System Config Value
type: Class
subclass of: System Config System Call
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database Record
type: NamedIndividual
modifies: System Configuration Database Record

Set Thread Context
type: Class
subclass of: System Call
subclass of: Restriction
  on property: modifies
  some values from: Thread
type: NamedIndividual
modifies: Thread

Shadow Stack
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: copy-of
  some values from: Call Stack
type: NamedIndividual
copy-of: Call Stack
definition: A shadow stack is a mechanism for protecting a procedure's stored return address, such as from a stack buffer overflow. The shadow stack itself is a second, separate stack that "shadows" the program call stack. In the function prologue, a function stores its return address to both the call stack and the shadow stack. In the function epilogue, a function loads the return address from both the call stack and the shadow stack, and then compares them. If the two records of the return address differ, then an attack is detected.

Shadow Stack Comparisons
type: Class
subclass of: Process Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Stack Frame
type: NamedIndividual
analyzes: Stack Frame
kb-reference: Reference-ThreatDetectionForReturnOrientedProgramming CrowdstrikeInc
d3fend-id: D3-SSC
definition: Comparing a call stack in system memory with a shadow call stack maintained by the processor to determine unauthorized shellcode activity.
kb-article: ## How it works This technique compares the call stack stored in system memory with the shadow call stack maintained in the cache memory of the processor. Mismatches between the two are compared since a return oriented programming attack may only be able to control or spoof the call stack and not the shadow call stack. Mismatches are counted and if the number of mismatches exceeds a certain threshold it is an indication of unauthorized activity and a security response action is performed. ## Considerations If the threshold for detecting a stack anomaly is low, it may not detect a return-oriented attack with just one gadget, such as a return-to-libc or return-to-plt attack. Additionally, this technique may not detect JOP (Jump-oriented programming), as the return instruction is not executed.

Shared Computer
type: Class
subclass of: Client Computer
definition: A computer whose resources are intended to be shared widely.

Shared Library File
type: Class
subclass of: Object File
type: NamedIndividual
definition: A shared library file is a file that is intended to be shared by executable files and further shared library (object) files. Modules used by a program are loaded from individual shared objects into memory at load time or runtime, rather than being copied by a linker when it creates a single monolithic executable file for the program
alternative label: Shared Library
alternative label: Shared Object

Shared Resource Access Function
type: Class
subclass of: Subroutine
subclass of: Restriction
  on property: accesses
  some values from: Resource
type: NamedIndividual
accesses: Resource
definition: A function which access a shared resource.

Shim
type: Class
subclass of: Software
type: NamedIndividual
definition: In computer programming, a shim is a small library that transparently intercepts API calls and changes the arguments passed, handles the operation itself, or redirects the operation elsewhere. Shims can be used to support an old API in a newer environment, or a new API in an older environment. Shims can also be used for running programs on different software platforms than those for which they were developed.

Shim Database
type: Class
subclass of: Application Configuration Database
type: NamedIndividual
definition: A application configuration database that contains or points to software shims (e.g., for backward compatibility, patches, etc.)

Shortcut File
type: Class
subclass of: File
definition: A shortcut file, or shortcut, is a handle that allows the user to find a file or resource located in a different directory or folder from the place where the shortcut is located. Shortcuts, which are supported by the graphical file browsers of some operating systems, may resemble symbolic links but differ in a number of important ways. One difference is what type of software is able to follow them: - Symbolic links are automatically resolved by the file system. Any software program, upon accessing a symbolic link, will see the target instead, whether the program is aware of symbolic links or not. - Shortcuts are treated like ordinary files by the file system and by software programs that are not aware of them. Only software programs that understand shortcuts (such as the Windows shell and file browsers) treat them as references to other files. Another difference are the capabilities of the mechanism: - Microsoft Windows shortcuts normally refer to a destination by an absolute path (starting from the root directory), whereas POSIX symbolic links can refer to destinations via either an absolute or a relative path. The latter is useful if both the location and destination of the symbolic link share a common path prefix[clarification needed], but that prefix is not yet known when the symbolic link is created (e.g., in an archive file that can be unpacked anywhere). - Microsoft Windows application shortcuts contain additional metadata that can be associated with the destination, whereas POSIX symbolic links are just strings that will be interpreted as absolute or relative pathnames. - Unlike symbolic links, Windows shortcuts maintain their references to their targets even when the target is moved or renamed. Windows domain clients may subscribe to a Windows service called Distributed Link Tracking to track the changes in files and folders to which they are interested. The service maintains the integrity of shortcuts, even when files and folders are moved across the netwo…

Simulation
type: Class
subclass of: Media Generation

Singular Value Decomposition
type: Class
subclass of: Dimension Reduction
type: NamedIndividual
d3fend-id: D3A-SVD
definition: Singular Value Decomposition (SVD) is an algorithm that represents a matrix as a linear series of data and to find the set of factors that will best predict an outcome
kb-article: ## References Wikipedia. (n.d.). Singular value decomposition. [Link](https://en.wikipedia.org/wiki/Singular_value_decomposition)

Skewness
type: Class
subclass of: Distribution Properties
type: NamedIndividual
d3fend-id: D3A-SKE
definition: Skewness is a measure of the asymmetry of the probability distribution of a real-valued random variable about its mean. The standardized moment of a probability distribution function.
kb-article: ## References Wikipedia. (n.d.). Skewness. [Link](https://en.wikipedia.org/wiki/Skewness)

Slow Symbolic Link
type: Class
subclass of: Symbolic Link
subclass of: Unix Link
definition: A slow symbolic link is any symbolic link on a Unix filesystem that is not a fast symbolic link; slow symlink is thus retroactively termed from fast symlink. Slow symbolic links stored the symbolic link information as data in regular files.
alternative label: Slow Symlink

Software
type: Class
subclass of: Digital Information
subclass of: Restriction
  on property: contains
  some values from: Executable File
subclass of: Restriction
  on property: implements
  some values from: Subroutine
subclass of: Restriction
  on property: instructs
  some values from: Process
type: NamedIndividual
contains: Executable File
implements: Subroutine
instructs: Process
definition: Computer software, or simply software, is that part of a computer system that consists of encoded information or computer instructions, in contrast to the physical hardware from which the system is built.

Software Artifact Server
type: Class
subclass of: Artifact Server
definition: A software artifact server provides access to the software artifacts in a software repository. A software repository, or "repo" for short, is a storage location for software packages. Often a table of contents is stored, as well as metadata. Repositories group packages. Sometimes the grouping is for a programming language, such as CPAN for the Perl programming language, sometimes for an entire operating system, sometimes the license of the contents is the criteria. At client side, a package manager helps installing from and updating the repositories.

Software Deployment Tool
type: Class
subclass of: Service Application
type: NamedIndividual
definition: Software that coordinates the deployment process of software to systems, typically remotely.

Software Inventory
type: Class
subclass of: Asset Inventory
subclass of: Restriction
  on property: inventories
  some values from: Software
type: NamedIndividual
inventories: Software
kb-reference: Reference-Web-BasedEnterpriseManagement
kb-reference: Reference-Windows-Management-Infrastructure
kb-reference: Reference-Windows-Management-Instrumentation
d3fend-id: D3-SWI
definition: Software inventorying identifies and records the software items in the organization's architecture.
kb-article: ## How it works Administrators collect information on software items in their architecture using a variety of administrative and management tools that query network nodes for information. In limited cases, where such queries are not supported or provide specific information of interest, an administrator may also collect this information through network enumeration methods to determine services responding on network nodes. ## Considerations * Scanning and probing techniques using mapping tools can result in side effects to information technology (IT) and operational technology (OT) systems. * An adversary conducting network enumeration may engage in activities that parallel normal software inventorying activities, but would require escalating to admin privileges for most of the operations requiting administrative tools. ## Examples Application-layer discovery: * Simple Network Management Protocol (SNMP) collects MIB information * Web-based Enterprise Management (WBEM) collects CIM information * Windows Management Instrumentation (WMI) * Windows Management Infrastructure (MI)
synonym: Software Discovery
synonym: Software Inventorying

Software Library
type: Class
subclass of: Software
subclass of: Restriction
  on property: contains
  some values from: Software Library File
type: NamedIndividual
contains: Software Library File
definition: A software library is a collection of software components that are used to build a software product.

Software Library File
type: Class
subclass of: File
subclass of: Restriction
  on property: contains
  some values from: Subroutine
subclass of: Restriction
  on property: may-contain
  some values from: Executable Binary
subclass of: Restriction
  on property: may-contain
  some values from: Executable Script
type: NamedIndividual
contains: Subroutine
may-contain: Executable Binary
may-contain: Executable Script
definition: A software library is a collection of software components that are used to build a software product.

Software Package
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual

Software Packaging Tool
type: Class
subclass of: Build Tool
definition: A tool that automates the process of packaging either or both binary code and source code for use on one or more target platforms.

Software Patch
type: Class
subclass of: Software
definition: A patch is a piece of software designed to update a computer program or its supporting data, to fix or improve it. This includes fixing security vulnerabilities and other bugs, with such patches usually called bugfixes or bug fixes, and improving the usability or performance. Although meant to fix problems, poorly designed patches can sometimes introduce new problems (see software regressions). In some special cases updates may knowingly break the functionality, for instance, by removing components for which the update provider is no longer licensed or disabling a device.
alternative label: Patch

Software Repository
type: Class
subclass of: Repository
subclass of: Restriction
  on property: contains
  some values from: Software Package
type: NamedIndividual
contains: Software Package
definition: A software repository, or repo for short, is a storage location for software packages. Often a table of contents is also stored, along with metadata. A software repository is typically managed by source or version control, or repository managers. Package managers allow automatically installing and updating repositories, sometimes called 'packages'.
alternative label: Package Repository

Software Update
type: Class
subclass of: Platform Hardening
subclass of: Restriction
  on property: updates
  some values from: Software
type: NamedIndividual
kb-reference: Reference-MethodAndSystemForProvidingSoftwareUpdatesToLocalMachines
updates: Software
d3fend-id: D3-SU
definition: Replacing old software on a computer system component.

Somers' D
type: Class
subclass of: Rank Correlation
type: NamedIndividual
d3fend-id: D3A-SD

Soundex Matching
type: Class
subclass of: Partial Matching
type: NamedIndividual
d3fend-id: D3A-SM
definition: Soundex is a phonetic algorithm for indexing names by sound, as pronounced in English.
kb-article: ## How it works The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling. The algorithm mainly encodes consonants; a vowel will not be encoded unless it is the first letter. Soundex is the most widely known of all phonetic algorithms (in part because it is a standard feature of popular database software. Improvements to Soundex are the basis for many modern phonetic algorithms. ## References 1. Soundex. (2023, April 19). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Soundex)

Source Code Analyzer Tool
type: Class
subclass of: Static Analysis Tool
definition: A source code analyzer tool is a static analysis tool that operates specifically on source code, but not object code.

Source Code Hardening
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Harden
type: NamedIndividual
enables: Harden
d3fend-id: D3-SCH
definition: Hardening source code with the intention of making it more difficult to exploit and less error prone.

Source Code Reference
type: Class
subclass of: Technique Reference
pref-label: Source Code

Spearman's Rank Correlation Coefficient
type: Class
subclass of: Rank Correlation
type: NamedIndividual
d3fend-id: D3A-SRCC
synonym: Spearman's Rho

Specification Reference
type: Class
subclass of: Technique Reference
pref-label: Specification

Spectral Clustering
type: Class
subclass of: Graph-based Clustering
type: NamedIndividual
d3fend-id: D3A-SC
definition: Spectral clustering is a technique that identifies communities of nodes in a graph based on the edges connecting them.
kb-article: ## References Towards Data Science. (n.d.). Spectral Clustering. [Link](https://towardsdatascience.com/spectral-clustering-aba2640c0d5b)

Stack Component
type: Class
subclass of: Digital Information Bearer
definition: A stack component is any component of a call stack used for stack-based memory allocation in a running process. Examples include saved instruction pointers, stack frames, and stack frame canaries.

Stack Frame
type: Class
subclass of: Stack Component
subclass of: Restriction
  on property: may-contain
  some values from: Pointer
subclass of: Restriction
  on property: may-contain
  some values from: Stack Frame Canary
type: NamedIndividual
may-contain: Pointer
may-contain: Stack Frame Canary
definition: A machine-dependent and application-binary-dependent (ABI-dependent) data structure containing subroutine state information including the arguments passed into the routine, the return address back to the routine's caller, and space for local variables of the routine.
alternative label: Activation Frame
alternative label: Activation Record

Stack Frame Canary
type: Class
subclass of: Stack Component
type: NamedIndividual
definition: Stack canaries, named for their analogy to a canary in a coal mine, are used to detect a stack buffer overflow before execution of malicious code can occur. This method works by placing a small integer, the value of which is randomly chosen at program start, in memory just before the stack return pointer. Most buffer overflows overwrite memory from lower to higher memory addresses, so in order to overwrite the return pointer (and thus take control of the process) the canary value must also be overwritten. This value is checked to make sure it has not changed before a routine uses the return pointer on the stack. This technique can greatly increase the difficulty of exploiting a stack buffer overflow because it forces the attacker to gain control of the instruction pointer by some non-traditional means such as corrupting other important variables on the stack.
alternative label: Stack Canary

Stack Frame Canary Validation
type: Class
subclass of: Application Hardening
subclass of: Restriction
  on property: validates
  some values from: Stack Frame
type: NamedIndividual
kb-reference: Reference-GS BufferSecurityCheck MicrosoftDocs
kb-reference: Reference-StackSmashingProtection StackGuard RedHat
validates: Stack Frame
d3fend-id: D3-SFCV
definition: Comparing a value stored in a stack frame with a known good value in order to prevent or detect a memory segment overwrite.
kb-article: ## How it works This defense must be applied at compile-time, or via a patch to the program binary. Stack Frame Canary Verification inserts instructions at the prologue and epilogue of desired functions. In the prologue, a canary value, typically with the same size as the register size, is stored in the system of record and on the stack. Typically, the canary is loaded to where it has a memory address just below that of the saved instruction pointer and base pointer. In the epilogue, the canary value stored on the stack and, is compared to the canary value in the system of record. If the values are different, other techniques such as those in Process Eviction might be invoked, such as Process Termination to end the current process, or Executable Blacklisting to blacklist the potentially vulnerable or malfunctioning executable. Stack Frame Canary Verification is commonly used to detect potential tampering of a saved register value on the stack before it has been restored. Examples of registers with values commonly saved to the stack include the instruction pointer and the base pointer. The canary should be stored between where the start of a buffer overrun is likely, and the data to protect, in cases where the buffer size increases it will overwrite the data to be protected. On most processor architectures, including x86, x64, and ARM, a "push" operation to store data to the stack grows the stack towards a lower memory address. As in these architectures, saved register values are stored to the stack at a point in time just before space is made for the local function variables, the saved register values have a higher address than that of the local function variables. Values at increasing indexes of a buffer are written to increasing memory addresses; therefore, an overwrite in the local variable buffer could overwrite saved register values, and a stack canary between these two would be useful in detecting an overwrite. On some other processor architectures such as the…

Stack Segment
type: Class
subclass of: Process Segment
subclass of: Restriction
  on property: contains
  some values from: Stack Frame
type: NamedIndividual
contains: Stack Frame
definition: The stack segment contains the program stack, a last-in-first-out structure, typically allocated in the higher parts of memory for the process.

Stacking
type: Class
subclass of: Ensemble Learning
type: NamedIndividual
d3fend-id: D3A-STA
definition: Stacking is a method of using the results and predictions from one layer of ML models as inputs to another layer of ML models. Stacking (sometimes called stacked generalization) involves training a model to combine the predictions of several other learning algorithms.
kb-article: ## References Ensemble learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Ensemble_learning).

Standalone Honeynet
type: Class
subclass of: Decoy Environment
subclass of: Restriction
  on property: spoofs
  some values from: Intranet Network
type: NamedIndividual
kb-reference: Reference-DynamicSelectionAndGenerationOfAVirtualCloneForDetonationOfSuspiciousContentWithinAHoneyNetwork PaloAltoNetworksInc
spoofs: Intranet Network
d3fend-id: D3-SHN
definition: An environment created for the purpose of attracting attackers and eliciting their behaviors that is not connected to any production enterprise systems.
kb-article: ## How it works A standalone honeynet does not directly interact with the real enterprise environment. It may be located near or in some portion of the enterprise address space, but it does not interact with enterprise resources. ## Considerations A standalone honeynet is a lower risk to deploy compared to connected or integrated honeynets due to its isolation from the enterprise network. However, this comes at cost in loss of fidelity and realism. Significant extra effort must be made in order to make the environment look realistic.

Standard Deviation
type: Class
subclass of: Variability
type: NamedIndividual
d3fend-id: D3A-SD
definition: The standard deviation is a measure of the amount of variation or dispersion of a set of values.
kb-article: ## References Wikipedia. (n.d.). Standard deviation. [Link](https://en.wikipedia.org/wiki/Standard_deviation)
synonym: SD

Startup Directory
type: Class
subclass of: Directory
subclass of: Local Resource
definition: A startup directory is a directory containing executable files or links to executable files which are run when a user logs in or when a system component or service is started.

Static Analysis Tool
type: Class
subclass of: Code Analyzer
definition: A static [program] analysis tool performs an automated analysis of computer software without actually executing programs, in contrast with dynamic analysis, which is analysis performed on programs while they are executing. In most cases the analysis is performed on some version of the source code, and in the other cases, some form of the object code.
alternative label: Static Program Analysis Tool

Statistical Method
type: Class
subclass of: Analytic Technique
type: NamedIndividual
d3fend-id: D3A-SM
definition: Building methods using the mathematical study of the likelihood and probability of events occurring based on known information and inferred by taking a limited number of samples.
kb-article: ## References Wolfram MathWorld. (n.d.). Statistics. [Link](https://mathworld.wolfram.com/Statistics.html)

Step
type: Class
subclass of: Plan
subclass of: Restriction
  on property: end
  some values from: Step
subclass of: Restriction
  on property: fork
  some values from: Step
subclass of: Restriction
  on property: may-be-associated-with
  some values from: Artifact
subclass of: Restriction
  on property: next
  some values from: Step

Storage
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: may-contain
  some values from: File System
type: NamedIndividual
may-contain: File System
definition: Computer data storage, often called storage or memory, is a technology consisting of computer components and recording media used to retain digital data. It is a core function and fundamental component of computers. In the Von Neumann architecture, the CPU consists of two main parts: The control unit and the arithmetic / logic unit (ALU). The former controls the flow of data between the CPU and memory, while the latter performs arithmetic and logical operations on data.
synonym: Computer data storage
synonym: Storage

Storage Device Event
type: Class
subclass of: Hardware Device Event
subclass of: Restriction
  on property: has-participant
  some values from: Secondary Storage
definition: An event describing the activity, configuration, or errors of storage devices, including physical disks, SSDs, or logical partitions. These events often pertain to data availability, integrity, and storage health.

Storage Image
type: Class
subclass of: Computing Image
subclass of: File
definition: A storage image is a complete, encapsulated representation of a storage medium or system environment. It contains all the data, files, and configurations necessary to replicate or deploy a specific system state or software setup.

Storage Snapshot
type: Class
subclass of: Computing Snapshot
definition: A storage snapshot is a copy of a storage medium or system environment at a point in time.

Stored Procedure
type: Class
subclass of: Subroutine
type: NamedIndividual
definition: A stored procedure (also termed proc, storp, sproc, StoPro, StoredProc, StoreProc, sp, or SP) is a subroutine available to applications that access a relational database management system (RDBMS). Such procedures are stored in the database data dictionary.

String Equivalence Matching
type: Class
subclass of: Equivalence Matching
subclass of: String Pattern Matching
type: NamedIndividual
d3fend-id: D3A-SEM
definition: String equivalence matching is a type of string pattern matching which is exact; that is, the strings being compared must have the same value for each character in their sequence and be of the same length.
kb-article: ## References 1. String-searching algorithm. (2023, April 8). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/String-searching_algorithm) 2. Types of Equality. (2007, March 2). In _WikiWikiWeb_. [Link](https://wiki.c2.com/?TypesOfEquality)

String Format Function
type: Class
subclass of: Subroutine
definition: A function which creates a new string based on a format specification and correspondingi specified values.

String Pattern Matching
type: Class
subclass of: Pattern Matching
type: NamedIndividual
d3fend-id: D3A-SPM
definition: String pattern-matching algorithms, also known as string-matching algorithms, are an important class of string algorithms that try to find a place where one or several strings (also called patterns) are found within a larger string or text
kb-article: ## How it works A basic example of string searching is when the pattern and the searched text are arrays of elements of an alphabet (finite set) Σ. Σ may be a human language alphabet, for example, the letters A through Z and other applications may use a binary alphabet (Σ = {0,1}) or a DNA alphabet (Σ = {A,C,G,T}) in bioinformatics. In practice, the method of feasible string-search algorithm may be affected by the string encoding. In particular, if a variable-width encoding is in use, then it may be slower to find the Nth character, perhaps requiring time proportional to N. This may significantly slow some search algorithms. One of many possible solutions is to search for the sequence of code units instead, but doing so may produce false matches unless the encoding is specifically designed to avoid it. ## References 1. String-searching algorithm. (2023, April 8). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/String-searching_algorithm)

Strong Password Policy
type: Class
subclass of: Credential Hardening
subclass of: Restriction
  on property: strengthens
  some values from: Password
type: NamedIndividual
kb-reference: Reference-DigitalIdentityGuidelines800-63-3
kb-reference: Reference-Testing Metrics for Password Creation Policies by Attacking Large Sets of Revealed Passwords
strengthens: Password
d3fend-id: D3-SPP
definition: Modifying system configuration to increase password strength.
kb-article: ## How it works Password strength guidelines include increasing password length, permitting passwords that contain ASCII or Unicode characters, and requiring systems to screen new passwords against lists of commonly used or compromised passwords. ## Considerations Extremely complex password requirements may lead users to saving passwords in text files or picking obvious passwords that meet the policy.

StyleGAN
type: Class
subclass of: Image Synthesis GAN
type: NamedIndividual
d3fend-id: D3A-STY
definition: Successor to the ProGAN.
kb-article: ## References Wikipedia. (n.d.). StyleGAN. [Link](https://en.wikipedia.org/wiki/StyleGAN)
synonym: Style GAN

Subroutine
type: Class
subclass of: Software
type: NamedIndividual
definition: In different programming languages, a subroutine may be called a procedure, a function, a routine, a method, or a subprogram. The generic term callable unit is sometimes used.
synonym: Method
synonym: Semantic Subroutine
synonym: Software Function

Subspace Clustering
type: Class
subclass of: Correlation Clustering
type: NamedIndividual
d3fend-id: D3A-SC
definition: Subspace clustering is an extension of traditional clustering that seeks to find clusters in different subspaces within a dataset.
kb-article: ## References Parsons, L., Haque, E., & Liu, H. (2004). Subspace Clustering for High Dimensional Data: A Review. [Link](https://www.kdd.org/exploration_files/parsons.pdf)

Substring Matching
type: Class
subclass of: Partial Matching
type: NamedIndividual
d3fend-id: D3A-SM
definition: String-searching algorithms, sometimes called string-matching algorithms, are an important class of string algorithms that try to find a place where one or several strings (also called patterns) are found within a larger string or text.
kb-article: ## References 1. String-searching algorithm. (2023, April 8). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/String-searching_algorithm)

Summarizing
type: Class
subclass of: Analytical Purpose

Supervised Learning
type: Class
subclass of: Machine Learning
type: NamedIndividual
d3fend-id: D3A-SL
definition: Supervised learning establishes a relationship between the known input and output variables to conduct a predictive analysis.
kb-article: ## References Supervised learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Supervised_learning).

Support Vector Machine Classification
type: Class
subclass of: Classification
type: NamedIndividual
d3fend-id: D3A-SVMC
definition: Support Vector Machine (SVM) is a robust classification and regression technique that maximizes the predictive accuracy of a model without overfitting the training data. SVM is particularly suited to analyzing data with very large numbers (for example, thousands) of predictor fields.
kb-article: ## References About Support Vector Machine (SVM). IBM SPSS Modeler SaaS Documentation. [Link](https://www.ibm.com/docs/en/spss-modeler/saas?topic=models-about-svm&mhsrc=ibmsearch_a&mhq=support%20vector%20machine).

Suspend Process
type: Class
subclass of: System Call
subclass of: Restriction
  on property: suspends
  some values from: Process
type: NamedIndividual
suspends: Process

Suspend Thread
type: Class
subclass of: System Call
subclass of: Restriction
  on property: suspends
  some values from: Thread
type: NamedIndividual
suspends: Thread
definition: Suspending a thread causes the thread to stop executing user-mode code.

Switch
type: Class
subclass of: Computer Network Node
definition: A network switch (also called switching hub, bridging hub, and by the IEEE MAC bridge) is networking hardware that connects devices on a computer network by using packet switching to receive and forward data to the destination device. A network switch is a multiport network bridge that uses MAC addresses to forward data at the data link layer (layer 2) of the OSI model. Some switches can also forward data at the network layer (layer 3) by additionally incorporating routing functionality. Such switches are commonly known as layer-3 switches or multilayer switches.
alternative label: Bridging Hub
alternative label: MAC Bridge
alternative label: Network Switch
alternative label: Switching Hub

Symbolic AI
type: Class
subclass of: Symbolic Logic
type: NamedIndividual
d3fend-id: D3A-SR
definition: Symbolic artificial intelligence is the term for the collection of all methods in artificial intelligence that are based on high-level symbolic (human-readable) representations of problems, logic, and search.
kb-article: ## How it works Symbolic artificial intelligence is used in tools such as logic programming, production rules, semantic nets and frames, and it developed applications such as knowledge-based systems (in particular, expert systems), symbolic mathematics, automated theorem provers, ontologies, the semantic web, and automated planning and scheduling systems. The Symbolic AI paradigm led to seminal ideas in search, symbolic programming languages, agents, multi-agent systems, the semantic web, and the strengths and limitations of formal knowledge and reasoning systems. ## References 1. Symbolic artifical intelligence. (2023, May 23). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Symbolic_artificial_intelligence)
synonym: Symbolic Artificial Intelligence

Symbolic Link
type: Class
subclass of: File
subclass of: File System Link
subclass of: Restriction
  on property: addresses
  some values from: File
type: NamedIndividual
addresses: File
definition: A symbolic link (also symlink or soft link) is a term for any file that contains a reference to another file or directory in the form of an absolute or relative path and that affects pathname resolution.
alternative label: Soft Link
alternative label: Softlink
alternative label: Symlink

Symbolic Logic
type: Class
subclass of: Analytic Technique
type: NamedIndividual
d3fend-id: D3A-SL
definition: Symbolic Logic, also known as formal logic, is a branch of mathematics that uses symbolic representations for logical expressions and relationships. It provides a systematic method for examining the structure of arguments and reasoning, focusing on the relationships between propositions rather than the content of those propositions.
kb-article: ## How it Works ## References 1. Symbolic Logic. (2023, June 6). In _Wolfram Mathworld_. [Link](https://mathworld.wolfram.com/SymbolicLogic.html) 2. Hughes, G. and Schagrin, M. (2023, Apr 19). Formal Logic. _Encyclopedia Brittanica_. [Link](https://www.britannica.com/topic/formal-logic) 3. Carnap, R. (1953). Introduction to Symbolic Logic and Its Applications. Dover Publications. [Link](https://archive.org/details/rudolf-carnap-introduction-to-symbolic-logic-and-its-applications/page/3/mode/2up)

Symmetric Feature-based Transfer Learning
type: Class
subclass of: Homogenous Transfer Learning
type: NamedIndividual
d3fend-id: D3A-SFTL
definition: Homogeneous symmetric transformation takes both the source feature space Xs and target feature space Xt and learns feature transformations as to project each onto a common subspace Xc for adaptation purposes. This derived subspace becomes a domain-invariant feature subspace to associate cross-domain data, and in effect, reduces marginal distribution differences.
kb-article: ## References Day, O., & Khoshgoftaar, T.M. (2017). A survey on heterogeneous transfer learning. *Journal of Big Data, 4*(1), 29. [Link](https://doi.org/10.1186/s40537-017-0089-0).

Symmetric Key
type: Class
subclass of: Cryptographic Key
definition: A symmetric key is a single key used for both encryption and decryption and used with a symmetric-key algorithm. Symmetric-key algorithms are algorithms for cryptography that use the same cryptographic keys for both encryption of plaintext and decryption of ciphertext. The keys may be identical or there may be a simple transformation to go between the two keys. The keys, in practice, represent a shared secret between two or more parties that can be used to maintain a private information link. This requirement that both parties have access to the secret key is one of the main drawbacks of symmetric key encryption, in comparison to public-key encrytption (also known as asymmetric key encryption).

System
type: Class
subclass of: Artifact
definition: An artifact (instrumentality) that combines interrelated interacting artifacts designed to work as a coherent entity. [Note that not all digital artifacts are systems nor are all systems digital artifacts.]

System Call
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: executes
  some values from: Subroutine
type: NamedIndividual
executes: Subroutine
definition: A system call is the programmatic way in which a computer program requests a service from the kernel of the operating system it is executed on. This may include hardware-related services (for example, accessing a hard disk drive), creation and execution of new processes, and communication with integral kernel services such as process scheduling. System calls provide an essential interface between a process and the operating system.
synonym: syscall

System Call Analysis
type: Class
subclass of: Process Analysis
subclass of: Restriction
  on property: analyzes
  some values from: System Call
type: NamedIndividual
analyzes: System Call
kb-reference: Reference-CredentialDumpingViaWindowsTaskManager MITRE
kb-reference: Reference-DLLInjectionViaLoadLibrary MITRE
kb-reference: Reference-Hardware-assistedSystemAndMethodForDetectingAndAnalyzingSystemCallsMadeToAnOpertingSystemKernel EndgameInc
kb-reference: Reference-MalwareDetectionInEventLoops CrowdstrikeInc
kb-reference: Reference-CAR-2020-05-001:MiniDumpOfLSASS MITRE
kb-reference: Reference-CAR-2021-05-011:CreateRemoteThreadIntoLSASS MITRE
d3fend-id: D3-SCA
definition: Analyzing system calls to determine whether a process is exhibiting unauthorized behavior.
kb-article: ## How it works System calls are APIs between a user application and the operating system [1]. By analyzing a process's use of these APIs, it is, in some cases, possible to ascertain whether a program is exhibiting unauthorized behavior, including trying to escalate its privileges. ### Gathering System Calls A common method to capture system calls is to use kernel APIs to hook [2] a process's system call invocations. The Linux system call `ptrace` tracks other system calls in a process and allows their alteration; this is made use of by GDB. `strace` utilizes `ptrace` and will print to stdout each system call invoked. Other applications record this data in local or remote databases. The log entry for each system call, which may reference additional information such as the date and time, and the process tree for the process which made the system call, is relayed, in real time or post-facto, to an analysis module which consults a catalog or model to determine whether the distribution matches a known-good or known-bad pattern. ### Analysis System calls are analyzed with a variety of methods. Some analytics look for specific sequences of instructions, others may apply statistical methods to identify abnormal behavior. Sequences of instructions can be abstracted into conceptually higher order user activities, for example: * An attacker executes many system calls in a short period of time, with several sequences which could be used to escalate privileges. * Getting the contents from a URL, writing to a new file, and then executing the same file. * A ransomware program which either uses a loop or creates many threads to: read a specified file, encrypt its contents, create an output file with a similar name to the original file, and delete the unencrypted original. ## Considerations * Duplicative or extraneous system calls may be added to malware to defeat analytics. * Malware could replace API hooking instructions to allow system calls to be made without being monitored. *…

System Call Event
type: Class
subclass of: Kernel Event
subclass of: Restriction
  on property: has-participant
  some values from: System Call
definition: An event where a user-space process requests a service or resource from the operating system kernel through a system call interface, enabling controlled interactions with hardware or kernel-level operations.

System Call Filtering
type: Class
subclass of: Access Mediation
subclass of: Restriction
  on property: filters
  some values from: System Call
subclass of: Restriction
  on property: isolates
  some values from: Process
type: NamedIndividual
filters: System Call
isolates: Process
kb-reference: Reference-AnalysisOfTheWindowsVistaSecurityModel SymantecCorporation
kb-reference: Reference-ArchitectureOfTransparentNetworkSecurityForApplicationContainers NeuvectorInc
kb-reference: Reference-OverviewOfTheSeccompSandbox
d3fend-id: D3-SCF
definition: Controlling access to local computer system resources with kernel-level capabilities.
kb-article: ## How it works System call filtering uses a mandatory access control paradigm (that is, a non-discretionary access control) system because the rules and polices that determine access is determined by a security control authority and not distributed to local users. Access determinations are based on designed access control polices and are not based on local resource owner determinations. Access is typically granted by defining sets of subjects and sets of objects. Subjects are the entities requesting access and objects are the resources that subjects are trying to access. Rules and policies are defined that associate subjects and object permissions and access controls. ### Common implementations #### Security label access control A fine-grained form control is to apply security labels to individual resources, including processes, and the access control decisions are against a particular resource and a given user attempting to gain access. This type of control requires that the file system has built-in support for security labels. Access controls are typically implemented through the use of label identifiers for every file system object. Identifier labels are applied to resources and users are assigned a similar access identifier. Users attempting to access a resource will result in the operating system performing an access control check. The access control check will compare the assigned user's credentials to that of the resource or object they are attempting to access. A security context is associated with resources and is used to determine assess. Typical basic access control elements include users, roles and types and together they form a security context which is the basis for the security labels. This type of access control is what is employed in SELinux [2]. This form of security kernel access control is considered the most flexible implementation, but it also is the most complex to deploy across the enterprise. Where multiple virtual machines (VM) are run tog…
synonym: System Call Control
alternative label: Mandatory Access Control
alternative label: System Call Mediation

System Config System Call
type: Class
subclass of: System Call

System Configuration Database
type: Class
subclass of: Database
type: NamedIndividual
definition: A database used to hold system configuration data.

System Configuration Database Record
type: Class
subclass of: Configuration Database Record
subclass of: Operating System Configuration Component
type: NamedIndividual
definition: A database record holding information used to configure the services, parameters, and initial settings for an operating system.

System Configuration Init Database Record
type: Class
subclass of: System Configuration Database Record
subclass of: System Configuration Init Resource
subclass of: System Init Configuration
type: NamedIndividual
definition: A database record holding information used to configure the services, parameters, and initial settings for an operating system at startup.
alternative label: System Configuration Startup Database Record

System Configuration Init Resource
type: Class
subclass of: Local Resource
definition: A system configuration initialization resource has information for initializing (booting) a system.
alternative label: System Init Resource

System Configuration Permissions
type: Class
subclass of: Platform Hardening
subclass of: Restriction
  on property: restricts
  some values from: System Configuration Database
type: NamedIndividual
kb-reference: Reference-HowToChangeRegistryValuesOrPermissionsFromACommandLineOrAScript
restricts: System Configuration Database
d3fend-id: D3-SCP
definition: Restricting system configuration modifications to a specific user or group of users.

System Daemon Monitoring
type: Class
subclass of: Operating System Monitoring
subclass of: Restriction
  on property: monitors
  some values from: Operating System Process
type: NamedIndividual
kb-reference: Reference-HostIntrusionPreventionSystemUsingSoftwareAndUserBehaviorAnalysis SophosLtd
kb-reference: Reference-MethodUsingKernelModeAssistanceForTheDetectionAndRemovalOfThreatsWhichAreActivelyPreventingDetectionAndRemovalFromARunningSystem SymantecCorporation
kb-reference: Reference-UserActivityFromStoppingWindowsDefensiveServices MITRE
monitors: Operating System Process
d3fend-id: D3-SDM
definition: Tracking changes to the state or configuration of critical system level processes.
kb-article: ## How it works Attackers may manipulate system settings or services to disable system logging or monitoring of security tools and events. Firewall and antivirus services are popular targets for attackers. Disabling system logs will also allow an attacker's actions to go unnoticed. Analysis of logs, registries, and process monitoring help defenders locate signs of tampering. Two possible approaches are to monitor hardened system services or to monitor registry updates for modifications to security settings.

System Dependency
type: Class
subclass of: Dependency
type: NamedIndividual
definition: A system dependency indicates a system has an activity, agent, or another system which relies on it in order to be functional.

System Dependency Mapping
type: Class
subclass of: System Mapping
subclass of: Restriction
  on property: maps
  some values from: System Dependency
type: NamedIndividual
kb-reference: Reference-CatiaUAFPlugin
kb-reference: Reference-SoftwareVulnerabilityGraphDatabase
kb-reference: Reference-UnifiedArchitectureFrameworkUAF
maps: System Dependency
d3fend-id: D3-SYSDM
definition: System dependency mapping identifies and models the dependencies of system components on each other to carry out their function.
kb-article: ## How it works The organization collects and models architectural information about the software, hardware, and products and maps the dependencies between systems, including each system's internal components and dependencies. ## Considerations * Data exchanges identified in the network mapping efforts usually indicate such dependencies, but may not be part of the intended design. * Architectural design artifacts and SMEs may need to be consulted to determine if dependencies are intended or otherwise essential. * System depedency mapping can identify internal dependencies of standard and pre-built systems that should be incorporated into a complete system dependency model. * System dependencies for critical systems--those supporting critical organizational activities--should be prioritized for supply chain risk analysis. * System dependencies should identify the integral components of a given named system and their structure to form a system. * System dependencies with a given system may be fixed by a particular product's configuration, and leveraging external knowledge bases about dependencies available (e.g., from package managers) is essential.

System File Analysis
type: Class
subclass of: Operating System Monitoring
subclass of: Restriction
  on property: analyzes
  some values from: Operating System File
type: NamedIndividual
analyzes: Operating System File
kb-reference: Reference-AccessPermissionModification MITRE
kb-reference: Reference-AutorunDifferences MITRE
kb-reference: Reference-UserActivityFromClearingEventLogs MITRE
d3fend-id: D3-SFA
definition: Monitoring system files such as authentication databases, configuration files, system logs, and system executables for modification or tampering.
kb-article: ## How it works This technique ensures the integrity of system owned file resources. System files can impact the behavior below the user level. ## Considerations * Need to manage the size of log file analysis. * False positives are a concern with this technique and filtering will need to be given additional thought. * A baseline or snapshot of file checksums should be established for future comparison.

System Firewall Configuration
type: Class
subclass of: Operating System Configuration Component
subclass of: Restriction
  on property: configures
  some values from: Host-based Firewall
type: NamedIndividual
configures: Host-based Firewall
definition: The configuration for a individual host operating system's firewall.

System Firmware
type: Class
subclass of: Firmware
type: NamedIndividual
definition: Firmware that is installed on a computer's main board which manages the initial boot process. It can also continue to run or function after the operating system boots.
alternative label: BIOS Firmware
alternative label: UEFI Firmware

System Firmware Verification
type: Class
subclass of: Firmware Verification
subclass of: Restriction
  on property: verifies
  some values from: System Firmware
type: NamedIndividual
kb-reference: Reference-FirmwareVerificationEclypsium
kb-reference: Reference-PlatformFirmwareResiliencyGuidelines NIST
verifies: System Firmware
d3fend-id: D3-SFV
definition: Cryptographically verifying installed system firmware integrity.
kb-article: ## How it works Cryptographic hash values are computed for system firmware. The hash values are compared against precomputed firmware hash values to determine if the firmware has been tampered with. When system firmware verification fails a set of predefined responses is typically invoked. The responses may direct the system to disable some devices or operations. ## Considerations * Requires the use of system provided security modules * Secure hash values will need to be computed for firmware

System Init Config Analysis
type: Class
subclass of: Operating System Monitoring
subclass of: Restriction
  on property: analyzes
  some values from: System Init Configuration
type: NamedIndividual
analyzes: System Init Configuration
kb-reference: Reference-AutorunDifferences MITRE
kb-reference: Reference-CAR-2020-09-005:AppInitDLLs MITRE
kb-reference: Reference-CAR-2020-11-001:BootOrLogonInitializationScripts MITRE
d3fend-id: D3-SICA
definition: Analysis of any system process startup configuration.
synonym: Autorun Analysis
synonym: Startup Analysis
alternative label: System Initialization Configuration Analysis

System Init Configuration
type: Class
subclass of: Operating System Configuration Component
type: NamedIndividual
definition: System initialization configuration information is configuration information used to configure the services, parameters, and initial settings for an operating system at startup.
alternative label: Autoruns

System Init Process
type: Class
subclass of: Operating System Process
definition: A system initialization process is a process that executes to initialize (boot) an operating system.
alternative label: System Initialization Process
alternative label: System Startup Process

System Init Script
type: Class
subclass of: Executable Script
subclass of: System Configuration Init Resource
subclass of: System Init Configuration
type: NamedIndividual
definition: A script used to initialize and configure elements of the system's environment, applications, services, or its operating system.

System Mapping
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Model
type: NamedIndividual
enables: Model
d3fend-id: D3-SYSM
definition: System mapping encompasses the techniques to identify the organization's systems, how they are configured and decomposed into subsystems and components, how they are dependent on one another, and where they are physically located.
display-order: 2

System Password Database
type: Class
subclass of: Password Database
type: NamedIndividual
definition: A password database used by a system service or process to authenticate users (e.g., Security Account Manager)

System Service Software
type: Class
subclass of: Software
subclass of: Restriction
  on property: contains
  some values from: Operating System File
type: NamedIndividual
contains: Operating System File
definition: Software services provided as part of the operating system, typically accessed through system calls.

System Software
type: Class
subclass of: Software
definition: Computer software which enables operating system or platform functionality.

System Startup Directory
type: Class
subclass of: Directory
subclass of: System Configuration Init Resource
subclass of: System Init Configuration
type: NamedIndividual
definition: A system startup directory is a directory containing executable files or links to executable files which are run when the system starts.

System State Image
type: Class
subclass of: Storage Image
type: NamedIndividual
definition: In computing, a system image is a serialized copy of the entire state of a computer system stored in some non-volatile form, such as a binary executable file.
alternative label: System Image

System Time Application
type: Class
subclass of: Utility Software
type: NamedIndividual
definition: A system time utility is utility software that can get the system time, such as the Unix date command or Windows' Net utility.

System Utilization Record
type: Class
subclass of: Record
definition: A system utilization record is a record for the tracking of resource utilization e.g. CPU, Disk, Network, Memory Bandwidth, GPU, or other resources for a given time period.

System Vulnerability Assessment
type: Class
subclass of: System Mapping
subclass of: Restriction
  on property: evaluates
  some values from: Digital System
subclass of: Restriction
  on property: identifies
  some values from: Vulnerability
type: NamedIndividual
evaluates: Digital System
identifies: Vulnerability
kb-reference: Reference-SoftwareVulnerabilityGraphDatabase
d3fend-id: D3-SYSVA
definition: System vulnerability assessment relates all the vulnerabilities of a system's components in the context of their configuration and internal dependencies and can also include assessing risk emerging from the system's design as a whole, not just the sum of individual component vulnerabilities.

Data Obfuscation
type: Class
subclass of: Command and Control Technique
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Network Traffic
type: NamedIndividual
produces: Outbound Internet Network Traffic
attack-id: T1001
definition: Adversaries may obfuscate command and control traffic to make it more difficult to detect.(Citation: Bitdefender FunnyDream Campaign November 2020) Command and control (C2) communications are hidden (but not necessarily encrypted) in an attempt to make the content more difficult to discover or decipher and to make the communication less conspicuous and hide commands from being seen. This encompasses many methods, such as adding junk data to protocol traffic, using steganography, or impersonating legitimate protocols.

Junk Data
type: Class
subclass of: Data Obfuscation
attack-id: T1001.001
definition: Adversaries may add junk data to protocols used for command and control to make detection more difficult.(Citation: FireEye SUNBURST Backdoor December 2020) By adding random or meaningless data to the protocols used for command and control, adversaries can prevent trivial methods for decoding, deciphering, or otherwise analyzing the traffic. Examples may include appending/prepending data with junk characters or writing junk characters between significant characters.

Steganography
type: Class
subclass of: Data Obfuscation
attack-id: T1001.002
definition: Adversaries may use steganographic techniques to hide command and control traffic to make detection efforts more difficult. Steganographic techniques can be used to hide data in digital messages that are transferred between systems. This hidden information can be used for command and control of compromised systems. In some cases, the passing of files embedded using steganography, such as image or document files, can be used for command and control.

Protocol or Service Impersonation
type: Class
subclass of: Data Obfuscation
attack-id: T1001.003
definition: Adversaries may impersonate legitimate protocols or web service traffic to disguise command and control activity and thwart analysis efforts. By impersonating legitimate protocols or web services, adversaries can make their command and control traffic blend in with legitimate network traffic.

Data Compressed
type: Class
subclass of: Exfiltration Technique
attack-id: T1002
definition: An adversary may compress data (e.g., sensitive documents) that is collected prior to exfiltration in order to make it portable and minimize the amount of data sent over the network. The compression is done separately from the exfiltration channel and is performed using a custom program or algorithm, or a more common compression library or utility such as 7zip, RAR, ZIP, or zlib.
comment: This technique has been revoked by T1560
deprecated: true

OS Credential Dumping
type: Class
subclass of: Credential Access Technique
attack-id: T1003
definition: Adversaries may attempt to dump credentials to obtain account login and credential material, normally in the form of a hash or a clear text password. Credentials can be obtained from OS caches, memory, or structures.(Citation: Brining MimiKatz to Unix) Credentials can then be used to perform [Lateral Movement](https://attack.mitre.org/tactics/TA0008) and access restricted information.

LSASS Memory
type: Class
subclass of: OS Credential Dumping
subclass of: Restriction
  on property: accesses
  some values from: Authentication Service
subclass of: Restriction
  on property: accesses
  some values from: Process
type: NamedIndividual
accesses: Authentication Service
accesses: Process
attack-id: T1003.001
definition: Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS). After a user logs on, the system generates and stores a variety of credential materials in LSASS process memory. These credential materials can be harvested by an administrative user or SYSTEM and used to conduct [Lateral Movement](https://attack.mitre.org/tactics/TA0008) using [Use Alternate Authentication Material](https://attack.mitre.org/techniques/T1550).

Security Account Manager
type: Class
subclass of: OS Credential Dumping
subclass of: Restriction
  on property: may-access
  some values from: Authentication Service
subclass of: Restriction
  on property: may-access
  some values from: Process
subclass of: Restriction
  on property: may-access
  some values from: System Password Database
type: NamedIndividual
may-access: Authentication Service
may-access: Process
may-access: System Password Database
attack-id: T1003.002
definition: Adversaries may attempt to extract credential material from the Security Account Manager (SAM) database either through in-memory techniques or through the Windows Registry where the SAM database is stored. The SAM is a database file that contains local accounts for the host, typically those found with the net user command. Enumerating the SAM database requires SYSTEM level access.

NTDS
type: Class
subclass of: OS Credential Dumping
subclass of: Restriction
  on property: accesses
  some values from: Encrypted Credential
type: NamedIndividual
accesses: Encrypted Credential
attack-id: T1003.003
definition: Adversaries may attempt to access or create a copy of the Active Directory domain database in order to steal credential information, as well as obtain other information about domain members such as devices, users, and access rights. By default, the NTDS file (NTDS.dit) is located in %SystemRoot%\NTDS\Ntds.dit of a domain controller.(Citation: Wikipedia Active Directory)

LSA Secrets
type: Class
subclass of: OS Credential Dumping
subclass of: Restriction
  on property: may-access
  some values from: Process
subclass of: Restriction
  on property: may-access
  some values from: System Password Database
type: NamedIndividual
may-access: Process
may-access: System Password Database
attack-id: T1003.004
definition: Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.(Citation: Passcape LSA Secrets)(Citation: Microsoft AD Admin Tier Model)(Citation: Tilbury Windows Credentials) LSA secrets are stored in the registry at HKEY_LOCAL_MACHINE\SECURITY\Policy\Secrets. LSA secrets can also be dumped from memory.(Citation: ired Dumping LSA Secrets)

Cached Domain Credentials
type: Class
subclass of: OS Credential Dumping
subclass of: Restriction
  on property: accesses
  some values from: Encrypted Credential
subclass of: Restriction
  on property: may-modify
  some values from: Log
type: NamedIndividual
accesses: Encrypted Credential
may-modify: Log
attack-id: T1003.005
definition: Adversaries may attempt to access cached domain credentials used to allow authentication to occur in the event a domain controller is unavailable.(Citation: Microsoft - Cached Creds)

DCSync
type: Class
subclass of: OS Credential Dumping
subclass of: Restriction
  on property: may-modify
  some values from: Event Log
subclass of: Restriction
  on property: produces
  some values from: Intranet Administrative Network Traffic
type: NamedIndividual
may-modify: Event Log
produces: Intranet Administrative Network Traffic
attack-id: T1003.006
definition: Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API)(Citation: Microsoft DRSR Dec 2017) (Citation: Microsoft GetNCCChanges) (Citation: Samba DRSUAPI) (Citation: Wine API samlib.dll) to simulate the replication process from a remote domain controller using a technique called DCSync.

Proc Filesystem
type: Class
subclass of: OS Credential Dumping
subclass of: Restriction
  on property: accesses
  some values from: Operating System File
subclass of: Restriction
  on property: accesses
  some values from: Process Image
type: NamedIndividual
accesses: Operating System File
accesses: Process Image
attack-id: T1003.007
definition: Adversaries may gather credentials from the proc filesystem or `/proc`. The proc filesystem is a pseudo-filesystem used as an interface to kernel data structures for Linux based systems managing virtual memory. For each process, the `/proc/<PID>/maps` file shows how memory is mapped within the process’s virtual address space. And `/proc/<PID>/mem`, exposed for debugging purposes, provides access to the process’s virtual address space.(Citation: Picus Labs Proc cump 2022)(Citation: baeldung Linux proc map 2022)

/etc/passwd and /etc/shadow
type: Class
subclass of: OS Credential Dumping
subclass of: Restriction
  on property: accesses
  some values from: Encrypted Credential
subclass of: Restriction
  on property: accesses
  some values from: Password File
type: NamedIndividual
accesses: Encrypted Credential
accesses: Password File
attack-id: T1003.008
definition: Adversaries may attempt to dump the contents of /etc/passwd and /etc/shadow to enable offline password cracking. Most modern Linux operating systems use a combination of /etc/passwd and /etc/shadow to store user account information including password hashes in /etc/shadow. By default, /etc/shadow is only readable by the root user.(Citation: Linux Password and Shadow File Formats)

Winlogon Helper DLL
type: Class
subclass of: Persistence Technique
attack-id: T1004
definition: Winlogon.exe is a Windows component responsible for actions at logon/logoff as well as the secure attention sequence (SAS) triggered by Ctrl-Alt-Delete. Registry entries in HKLM\Software\[Wow6432Node\]Microsoft\Windows NT\CurrentVersion\Winlogon\ and HKCU\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\ are used to manage additional helper programs and functionalities that support Winlogon. (Citation: Cylance Reg Persistence Sept 2013)
comment: This technique has been revoked by T1547.004
deprecated: true

Data from Local System
type: Class
subclass of: Collection Technique
subclass of: Restriction
  on property: accesses
  some values from: File
subclass of: Restriction
  on property: accesses
  some values from: Local Resource
type: NamedIndividual
accesses: File
accesses: Local Resource
attack-id: T1005
definition: Adversaries may search local system sources, such as file systems and configuration files or local databases, to find files of interest and sensitive data prior to Exfiltration.

Direct Volume Access
type: Class
subclass of: Defense Evasion Technique
subclass of: Restriction
  on property: accesses
  some values from: Volume
type: NamedIndividual
accesses: Volume
attack-id: T1006
definition: Adversaries may directly access a volume to bypass file access controls and file system monitoring. Windows allows programs to have direct access to logical volumes. Programs with direct access may read and write files directly from the drive by analyzing file system data structures. This technique may bypass Windows file access controls as well as file system monitoring tools. (Citation: Hakobyan 2009)

System Service Discovery
type: Class
subclass of: Discovery Technique
subclass of: Restriction
  on property: may-invoke
  some values from: Create Process
subclass of: Restriction
  on property: may-invoke
  some values from: Get Running Processes
type: NamedIndividual
may-invoke: Create Process
may-invoke: Get Running Processes
attack-id: T1007
definition: Adversaries may try to gather information about registered local system services. Adversaries may obtain information about services using tools as well as OS utility commands such as sc query, tasklist /svc, systemctl --type=service, and net start.

Fallback Channels
type: Class
subclass of: Command and Control Technique
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Network Traffic
type: NamedIndividual
produces: Outbound Internet Network Traffic
attack-id: T1008
definition: Adversaries may use fallback or alternate communication channels if the primary channel is compromised or inaccessible in order to maintain reliable command and control and to avoid data transfer thresholds.

Binary Padding
type: Class
subclass of: Defense Evasion Technique
attack-id: T1009
definition: Adversaries can use binary padding to add junk data and change the on-disk representation of malware without affecting the functionality or behavior of the binary. This will often increase the size of the binary beyond what some security tools are capable of handling due to file size limitations.
comment: This technique has been revoked by T1027.001
deprecated: true

Application Window Discovery
type: Class
subclass of: Discovery Technique
subclass of: Restriction
  on property: may-invoke
  some values from: Create Process
subclass of: Restriction
  on property: may-invoke
  some values from: Get Open Windows
type: NamedIndividual
may-invoke: Create Process
may-invoke: Get Open Windows
attack-id: T1010
definition: Adversaries may attempt to get a listing of open application windows. Window listings could convey information about how the system is used.(Citation: Prevailion DarkWatchman 2021) For example, information about application windows could be used identify potential data to collect as well as identifying security tooling ([Security Software Discovery](https://attack.mitre.org/techniques/T1518/001)) to evade.(Citation: ESET Grandoreiro April 2020)

Exfiltration Over Other Network Medium
type: Class
subclass of: Exfiltration Technique
subclass of: Restriction
  on property: produces
  some values from: Internet Network Traffic
type: NamedIndividual
produces: Internet Network Traffic
attack-id: T1011
definition: Adversaries may attempt to exfiltrate data over a different network medium than the command and control channel. If the command and control network is a wired Internet connection, the exfiltration may occur, for example, over a WiFi connection, modem, cellular data connection, Bluetooth, or another radio frequency (RF) channel.

Exfiltration Over Bluetooth
type: Class
subclass of: Exfiltration Over Other Network Medium
attack-id: T1011.001
definition: Adversaries may attempt to exfiltrate data over Bluetooth rather than the command and control channel. If the command and control network is a wired Internet connection, an adversary may opt to exfiltrate data using a Bluetooth communication channel.

Query Registry
type: Class
subclass of: Discovery Technique
subclass of: Restriction
  on property: accesses
  some values from: System Configuration Database
subclass of: Restriction
  on property: may-invoke
  some values from: Get System Config Value
type: NamedIndividual
accesses: System Configuration Database
may-invoke: Get System Config Value
attack-id: T1012
definition: Adversaries may interact with the Windows Registry to gather information about the system, configuration, and installed software.

Port Monitors
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1013
definition: A port monitor can be set through the (Citation: AddMonitor) API call to set a DLL to be loaded at startup. (Citation: AddMonitor) This DLL can be located in C:\Windows\System32 and will be loaded by the print spooler service, spoolsv.exe, on boot. The spoolsv.exe process also runs under SYSTEM level permissions. (Citation: Bloxham) Alternatively, an arbitrary DLL can be loaded if permissions allow writing a fully-qualified pathname for that DLL to HKLM\SYSTEM\CurrentControlSet\Control\Print\Monitors.
comment: This technique has been revoked by T1547.010
deprecated: true

Rootkit
type: Class
subclass of: Defense Evasion Technique
subclass of: Restriction
  on property: may-modify
  some values from: Boot Sector
subclass of: Restriction
  on property: may-modify
  some values from: Firmware
subclass of: Restriction
  on property: may-modify
  some values from: Kernel
subclass of: Restriction
  on property: may-modify
  some values from: Kernel Module
subclass of: Restriction
  on property: may-modify
  some values from: Shared Library File
type: NamedIndividual
may-modify: Boot Sector
may-modify: Firmware
may-modify: Kernel
may-modify: Kernel Module
may-modify: Shared Library File
attack-id: T1014
definition: Adversaries may use rootkits to hide the presence of programs, files, network connections, services, drivers, and other system components. Rootkits are programs that hide the existence of malware by intercepting/hooking and modifying operating system API calls that supply system information. (Citation: Symantec Windows Rootkits)

Accessibility Features
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1015
definition: Windows contains accessibility features that may be launched with a key combination before a user has logged in (for example, when the user is on the Windows logon screen). An adversary can modify the way these programs are launched to get a command prompt or backdoor without logging in to the system.
comment: This technique has been revoked by T1546.008
deprecated: true

System Network Configuration Discovery
type: Class
subclass of: Discovery Technique
subclass of: Restriction
  on property: may-execute
  some values from: Executable Script
subclass of: Restriction
  on property: may-invoke
  some values from: Create Process
subclass of: Restriction
  on property: may-invoke
  some values from: Get System Network Config Value
type: NamedIndividual
may-execute: Executable Script
may-invoke: Create Process
may-invoke: Get System Network Config Value
attack-id: T1016
definition: Adversaries may look for details about the network configuration and settings, such as IP and/or MAC addresses, of systems they access or through information discovery of remote systems. Several operating system administration utilities exist that can be used to gather this information. Examples include [Arp](https://attack.mitre.org/software/S0099), [ipconfig](https://attack.mitre.org/software/S0100)/[ifconfig](https://attack.mitre.org/software/S0101), [nbtstat](https://attack.mitre.org/software/S0102), and [route](https://attack.mitre.org/software/S0103).

Internet Connection Discovery
type: Class
subclass of: System Network Configuration Discovery
attack-id: T1016.001
definition: Adversaries may check for Internet connectivity on compromised systems. This may be performed during automated discovery and can be accomplished in numerous ways such as using [Ping](https://attack.mitre.org/software/S0097), tracert, and GET requests to websites.

Wi-Fi Discovery
type: Class
subclass of: System Network Configuration Discovery
attack-id: T1016.002
definition: Adversaries may search for information about Wi-Fi networks, such as network names and passwords, on compromised systems. Adversaries may use Wi-Fi information as part of [Account Discovery](https://attack.mitre.org/techniques/T1087), [Remote System Discovery](https://attack.mitre.org/techniques/T1018), and other discovery or [Credential Access](https://attack.mitre.org/tactics/TA0006) activity to support both ongoing and future campaigns.

Application Deployment Software
type: Class
subclass of: Lateral Movement Technique
attack-id: T1017
definition: Adversaries may deploy malicious software to systems within a network using application deployment systems employed by enterprise administrators. The permissions required for this action vary by system configuration; local credentials may be sufficient with direct access to the deployment server, or specific domain credentials may be required. However, the system may require an administrative account to log in or to perform software deployment.
comment: This technique has been revoked by T1072
deprecated: true

Remote System Discovery
type: Class
subclass of: Discovery Technique
subclass of: Restriction
  on property: may-access
  some values from: Operating System Configuration File
subclass of: Restriction
  on property: may-invoke
  some values from: Create Process
subclass of: Restriction
  on property: may-invoke
  some values from: Create Socket
subclass of: Restriction
  on property: produces
  some values from: Network Traffic
type: NamedIndividual
may-access: Operating System Configuration File
may-invoke: Create Process
may-invoke: Create Socket
produces: Network Traffic
attack-id: T1018
definition: Adversaries may attempt to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for Lateral Movement from the current system. Functionality could exist within remote access tools to enable this, but utilities available on the operating system could also be used such as [Ping](https://attack.mitre.org/software/S0097) or net view using [Net](https://attack.mitre.org/software/S0039).

System Firmware
type: Class
subclass of: Persistence Technique
attack-id: T1019
definition: The BIOS (Basic Input/Output System) and The Unified Extensible Firmware Interface (UEFI) or Extensible Firmware Interface (EFI) are examples of system firmware that operate as the software interface between the operating system and hardware of a computer. (Citation: Wikipedia BIOS) (Citation: Wikipedia UEFI) (Citation: About UEFI)
comment: This technique has been revoked by T1542.001
deprecated: true

Automated Exfiltration
type: Class
subclass of: Exfiltration Technique
subclass of: Restriction
  on property: produces
  some values from: Internet Network Traffic
type: NamedIndividual
produces: Internet Network Traffic
attack-id: T1020
definition: Adversaries may exfiltrate data, such as sensitive documents, through the use of automated processing after being gathered during Collection.(Citation: ESET Gamaredon June 2020)

Traffic Duplication
type: Class
subclass of: Automated Exfiltration
attack-id: T1020.001
definition: Adversaries may leverage traffic mirroring in order to automate data exfiltration over compromised infrastructure. Traffic mirroring is a native feature for some devices, often used for network analysis. For example, devices may be configured to forward network traffic to one or more destinations for analysis by a network analyzer or other monitoring device. (Citation: Cisco Traffic Mirroring)(Citation: Juniper Traffic Mirroring)

Remote Services
type: Class
subclass of: Lateral Movement Technique
subclass of: Restriction
  on property: produces
  some values from: Intranet Network Traffic
type: NamedIndividual
produces: Intranet Network Traffic
attack-id: T1021
definition: Adversaries may use [Valid Accounts](https://attack.mitre.org/techniques/T1078) to log into a service that accepts remote connections, such as telnet, SSH, and VNC. The adversary may then perform actions as the logged-on user.

Remote Desktop Protocol
type: Class
subclass of: Remote Services
subclass of: Restriction
  on property: creates
  some values from: RDP Session
subclass of: Restriction
  on property: produces
  some values from: Administrative Network Traffic
type: NamedIndividual
creates: RDP Session
produces: Administrative Network Traffic
attack-id: T1021.001
definition: Adversaries may use [Valid Accounts](https://attack.mitre.org/techniques/T1078) to log into a computer using the Remote Desktop Protocol (RDP). The adversary may then perform actions as the logged-on user.

SMB/Windows Admin Shares
type: Class
subclass of: Remote Services
attack-id: T1021.002
definition: Adversaries may use [Valid Accounts](https://attack.mitre.org/techniques/T1078) to interact with a remote network share using Server Message Block (SMB). The adversary may then perform actions as the logged-on user.

Distributed Component Object Model
type: Class
subclass of: Remote Services
attack-id: T1021.003
definition: Adversaries may use [Valid Accounts](https://attack.mitre.org/techniques/T1078) to interact with remote machines by taking advantage of Distributed Component Object Model (DCOM). The adversary may then perform actions as the logged-on user.

SSH
type: Class
subclass of: Remote Services
subclass of: Restriction
  on property: creates
  some values from: SSH Session
subclass of: Restriction
  on property: produces
  some values from: Administrative Network Traffic
type: NamedIndividual
creates: SSH Session
produces: Administrative Network Traffic
attack-id: T1021.004
definition: Adversaries may use [Valid Accounts](https://attack.mitre.org/techniques/T1078) to log into remote machines using Secure Shell (SSH). The adversary may then perform actions as the logged-on user.

VNC
type: Class
subclass of: Remote Services
attack-id: T1021.005
definition: Adversaries may use [Valid Accounts](https://attack.mitre.org/techniques/T1078) to remotely control machines using Virtual Network Computing (VNC). VNC is a platform-independent desktop sharing system that uses the RFB (“remote framebuffer”) protocol to enable users to remotely control another computer’s display by relaying the screen, mouse, and keyboard inputs over the network.(Citation: The Remote Framebuffer Protocol)

Windows Remote Management
type: Class
subclass of: Remote Services
attack-id: T1021.006
definition: Adversaries may use [Valid Accounts](https://attack.mitre.org/techniques/T1078) to interact with remote systems using Windows Remote Management (WinRM). The adversary may then perform actions as the logged-on user.

Cloud Services
type: Class
subclass of: Remote Services
attack-id: T1021.007
definition: Adversaries may log into accessible cloud services within a compromised environment using [Valid Accounts](https://attack.mitre.org/techniques/T1078) that are synchronized with or federated to on-premises user identities. The adversary may then perform management actions or access cloud-hosted resources as the logged-on user.

Direct Cloud VM Connections
type: Class
subclass of: Remote Services
attack-id: T1021.008
definition: Adversaries may leverage [Valid Accounts](https://attack.mitre.org/techniques/T1078) to log directly into accessible cloud hosted compute infrastructure through cloud native methods. Many cloud providers offer interactive connections to virtual infrastructure that can be accessed through the [Cloud API](https://attack.mitre.org/techniques/T1059/009), such as Azure Serial Console(Citation: Azure Serial Console), AWS EC2 Instance Connect(Citation: EC2 Instance Connect)(Citation: lucr-3: Getting SaaS-y in the cloud), and AWS System Manager.(Citation: AWS System Manager).

Data Encrypted
type: Class
subclass of: Exfiltration Technique
attack-id: T1022
definition: Data is encrypted before being exfiltrated in order to hide the information that is being exfiltrated from detection or to make the exfiltration less conspicuous upon inspection by a defender. The encryption is performed by a utility, programming library, or custom algorithm on the data itself and is considered separate from any encryption performed by the command and control or file transfer protocol. Common file archive formats that can encrypt files are RAR and zip.
comment: This technique has been revoked by T1560
deprecated: true

Shortcut Modification
type: Class
subclass of: Persistence Technique
attack-id: T1023
definition: Shortcuts or symbolic links are ways of referencing other files or programs that will be opened or executed when the shortcut is clicked or executed by a system startup process. Adversaries could use shortcuts to execute their tools for persistence. They may create a new shortcut as a means of indirection that may use [Masquerading](https://attack.mitre.org/techniques/T1036) to look like a legitimate program. Adversaries could also edit the target path or entirely replace an existing shortcut so their tools will be executed instead of the intended legitimate program.
comment: This technique has been revoked by T1547.009
deprecated: true

Custom Cryptographic Protocol
type: Class
subclass of: Command and Control Technique
attack-id: T1024
definition: Adversaries may use a custom cryptographic protocol or algorithm to hide command and control traffic. A simple scheme, such as XOR-ing the plaintext with a fixed key, will produce a very weak ciphertext.
comment: This technique has been revoked by T1573
deprecated: true

Data from Removable Media
type: Class
subclass of: Collection Technique
subclass of: Restriction
  on property: accesses
  some values from: Removable Media Device
type: NamedIndividual
accesses: Removable Media Device
attack-id: T1025
definition: Adversaries may search connected removable media on computers they have compromised to find files of interest. Sensitive data can be collected from any removable media (optical disk drive, USB memory, etc.) connected to the compromised system prior to Exfiltration. Interactive command shells may be in use, and common functionality within [cmd](https://attack.mitre.org/software/S0106) may be used to gather information.

Multiband Communication
type: Class
subclass of: Command and Control Technique
attack-id: T1026
definition: **This technique has been deprecated and should no longer be used.**
comment: **This technique has been deprecated and should no longer be used.**
deprecated: true

Obfuscated Files or Information
type: Class
subclass of: Defense Evasion Technique
attack-id: T1027
definition: Adversaries may attempt to make an executable or file difficult to discover or analyze by encrypting, encoding, or otherwise obfuscating its contents on the system or in transit. This is common behavior that can be used across different platforms and the network to evade defenses.

Binary Padding
type: Class
subclass of: Obfuscated Files or Information
subclass of: Restriction
  on property: modifies
  some values from: Executable Binary
type: NamedIndividual
modifies: Executable Binary
attack-id: T1027.001
definition: Adversaries may use binary padding to add junk data and change the on-disk representation of malware. This can be done without affecting the functionality or behavior of a binary, but can increase the size of the binary beyond what some security tools are capable of handling due to file size limitations.

Software Packing
type: Class
subclass of: Obfuscated Files or Information
subclass of: Restriction
  on property: obfuscates
  some values from: Executable File
type: NamedIndividual
obfuscates: Executable File
attack-id: T1027.002
definition: Adversaries may perform software packing or virtual machine software protection to conceal their code. Software packing is a method of compressing or encrypting an executable. Packing an executable changes the file signature in an attempt to avoid signature-based detection. Most decompression techniques decompress the executable code in memory. Virtual machine software protection translates an executable's original code into a special format that only a special virtual machine can run. A virtual machine is then called to run this code.(Citation: ESET FinFisher Jan 2018)

Steganography
type: Class
subclass of: Obfuscated Files or Information
attack-id: T1027.003
definition: Adversaries may use steganography techniques in order to prevent the detection of hidden information. Steganographic techniques can be used to hide data in digital media such as images, audio tracks, video clips, or text files.

Compile After Delivery
type: Class
subclass of: Obfuscated Files or Information
subclass of: Restriction
  on property: creates
  some values from: Executable File
type: NamedIndividual
creates: Executable File
attack-id: T1027.004
definition: Adversaries may attempt to make payloads difficult to discover and analyze by delivering files to victims as uncompiled code. Text-based source code files may subvert analysis and scrutiny from protections targeting executables/binaries. These payloads will need to be compiled before execution; typically via native utilities such as csc.exe or GCC/MinGW.(Citation: ClearSky MuddyWater Nov 2018)

Indicator Removal from Tools
type: Class
subclass of: Obfuscated Files or Information
attack-id: T1027.005
definition: Adversaries may remove indicators from tools if they believe their malicious tool was detected, quarantined, or otherwise curtailed. They can modify the tool by removing the indicator and using the updated version that is no longer detected by the target's defensive systems or subsequent targets that may use similar systems.

HTML Smuggling
type: Class
subclass of: Obfuscated Files or Information
subclass of: Restriction
  on property: creates
  some values from: JavaScript Blob
subclass of: Restriction
  on property: hides
  some values from: Digital Artifact
type: NamedIndividual
creates: JavaScript Blob
hides: Digital Artifact
attack-id: T1027.006
definition: Adversaries may smuggle data and files past content filters by hiding malicious payloads inside of seemingly benign HTML files. HTML documents can store large binary objects known as JavaScript Blobs (immutable data that represents raw bytes) that can later be constructed into file-like objects. Data may also be stored in Data URLs, which enable embedding media type or MIME files inline of HTML documents. HTML5 also introduced a download attribute that may be used to initiate file downloads.(Citation: HTML Smuggling Menlo Security 2020)(Citation: Outlflank HTML Smuggling 2018)

Dynamic API Resolution
type: Class
subclass of: Obfuscated Files or Information
attack-id: T1027.007
definition: Adversaries may obfuscate then dynamically resolve API functions called by their malware in order to conceal malicious functionalities and impair defensive analysis. Malware commonly uses various [Native API](https://attack.mitre.org/techniques/T1106) functions provided by the OS to perform various tasks such as those involving processes, files, and other system artifacts.

Stripped Payloads
type: Class
subclass of: Obfuscated Files or Information
attack-id: T1027.008
definition: Adversaries may attempt to make a payload difficult to analyze by removing symbols, strings, and other human readable information. Scripts and executables may contain variables names and other strings that help developers document code functionality. Symbols are often created by an operating system’s `linker` when executable payloads are compiled. Reverse engineers use these symbols and strings to analyze code and to identify functionality in payloads.(Citation: Mandiant golang stripped binaries explanation)(Citation: intezer stripped binaries elf files 2018)

Embedded Payloads
type: Class
subclass of: Obfuscated Files or Information
attack-id: T1027.009
definition: Adversaries may embed payloads within other files to conceal malicious content from defenses. Otherwise seemingly benign files (such as scripts and executables) may be abused to carry and obfuscate malicious payloads and content. In some cases, embedded payloads may also enable adversaries to [Subvert Trust Controls](https://attack.mitre.org/techniques/T1553) by not impacting execution controls such as digital signatures and notarization tickets.(Citation: Sentinel Labs)

Command Obfuscation
type: Class
subclass of: Obfuscated Files or Information
attack-id: T1027.010
definition: Adversaries may obfuscate content during command execution to impede detection. Command-line obfuscation is a method of making strings and patterns within commands and scripts more difficult to signature and analyze. This type of obfuscation can be included within commands executed by delivered payloads (e.g., [Phishing](https://attack.mitre.org/techniques/T1566) and [Drive-by Compromise](https://attack.mitre.org/techniques/T1189)) or interactively via [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059).(Citation: Akamai JS)(Citation: Malware Monday VBE)

Fileless Storage
type: Class
subclass of: Obfuscated Files or Information
attack-id: T1027.011
definition: Adversaries may store data in "fileless" formats to conceal malicious activity from defenses. Fileless storage can be broadly defined as any format other than a file. Common examples of non-volatile fileless storage include the Windows Registry, event logs, or WMI repository.(Citation: Microsoft Fileless)(Citation: SecureList Fileless)

LNK Icon Smuggling
type: Class
subclass of: Obfuscated Files or Information
attack-id: T1027.012
definition: Adversaries may smuggle commands to download malicious payloads past content filters by hiding them within otherwise seemingly benign windows shortcut files. Windows shortcut files (.LNK) include many metadata fields, including an icon location field (also known as the `IconEnvironmentDataBlock`) designed to specify the path to an icon file that is to be displayed for the LNK file within a host directory.

Encrypted/Encoded File
type: Class
subclass of: Obfuscated Files or Information
attack-id: T1027.013
definition: Adversaries may encrypt or encode files to obfuscate strings, bytes, and other specific patterns to impede detection. Encrypting and/or encoding file content aims to conceal malicious artifacts within a file used in an intrusion. Many other techniques, such as [Software Packing](https://attack.mitre.org/techniques/T1027/002), [Steganography](https://attack.mitre.org/techniques/T1027/003), and [Embedded Payloads](https://attack.mitre.org/techniques/T1027/009), share this same broad objective. Encrypting and/or encoding files could lead to a lapse in detection of static signatures, only for this malicious content to be revealed (i.e., [Deobfuscate/Decode Files or Information](https://attack.mitre.org/techniques/T1140)) at the time of execution/use.

Polymorphic Code
type: Class
subclass of: Obfuscated Files or Information
attack-id: T1027.014
definition: Adversaries may utilize polymorphic code (also known as metamorphic or mutating code) to evade detection. Polymorphic code is a type of software capable of changing its runtime footprint during code execution.(Citation: polymorphic-blackberry) With each execution of the software, the code is mutated into a different version of itself that achieves the same purpose or objective as the original. This functionality enables the malware to evade traditional signature-based defenses, such as antivirus and antimalware tools.(Citation: polymorphic-sentinelone)

Windows Remote Management
type: Class
subclass of: Execution Technique
subclass of: Lateral Movement Technique
attack-id: T1028
definition: Windows Remote Management (WinRM) is the name of both a Windows service and a protocol that allows a user to interact with a remote system (e.g., run an executable, modify the Registry, modify services). (Citation: Microsoft WinRM) It may be called with the winrm command or by any number of programs such as PowerShell. (Citation: Jacobsen 2014)
comment: This technique has been revoked by T1021.006
deprecated: true

Scheduled Transfer
type: Class
subclass of: Exfiltration Technique
subclass of: Restriction
  on property: produces
  some values from: Internet Network Traffic
type: NamedIndividual
produces: Internet Network Traffic
attack-id: T1029
definition: Adversaries may schedule data exfiltration to be performed only at certain times of day or at certain intervals. This could be done to blend traffic patterns with normal activity or availability.

Data Transfer Size Limits
type: Class
subclass of: Exfiltration Technique
subclass of: Restriction
  on property: produces
  some values from: Internet Network Traffic
type: NamedIndividual
produces: Internet Network Traffic
attack-id: T1030
definition: An adversary may exfiltrate data in fixed size chunks instead of whole files or limit packet sizes below certain thresholds. This approach may be used to avoid triggering network data transfer threshold alerts.

Modify Existing Service
type: Class
subclass of: Persistence Technique
attack-id: T1031
definition: Windows service configuration information, including the file path to the service's executable or recovery programs/commands, is stored in the Registry. Service configurations can be modified using utilities such as sc.exe and [Reg](https://attack.mitre.org/software/S0075).
comment: This technique has been revoked by T1543.003
deprecated: true

Standard Cryptographic Protocol
type: Class
subclass of: Command and Control Technique
attack-id: T1032
definition: Adversaries may explicitly employ a known encryption algorithm to conceal command and control traffic rather than relying on any inherent protections provided by a communication protocol. Despite the use of a secure algorithm, these implementations may be vulnerable to reverse engineering if necessary secret keys are encoded and/or generated within malware samples/configuration files.
comment: This technique has been revoked by T1573
deprecated: true

System Owner/User Discovery
type: Class
subclass of: Discovery Technique
subclass of: Restriction
  on property: may-access
  some values from: Directory Service
subclass of: Restriction
  on property: may-access
  some values from: Get System Config Value
subclass of: Restriction
  on property: may-access
  some values from: Password File
subclass of: Restriction
  on property: may-access
  some values from: Process Segment
subclass of: Restriction
  on property: may-invoke
  some values from: Copy Token
subclass of: Restriction
  on property: may-invoke
  some values from: Create Process
type: NamedIndividual
may-access: Directory Service
may-access: Get System Config Value
may-access: Password File
may-access: Process Segment
may-invoke: Copy Token
may-invoke: Create Process
attack-id: T1033
definition: Adversaries may attempt to identify the primary user, currently logged in user, set of users that commonly uses a system, or whether a user is actively using the system. They may do this, for example, by retrieving account usernames or by using [OS Credential Dumping](https://attack.mitre.org/techniques/T1003). The information may be collected in a number of different ways using other Discovery techniques, because user and username details are prevalent throughout a system and include running process ownership, file/directory ownership, session information, and system logs. Adversaries may use the information from [System Owner/User Discovery](https://attack.mitre.org/techniques/T1033) during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.

Path Interception
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1034
definition: **This technique has been deprecated. Please use [Path Interception by PATH Environment Variable](https://attack.mitre.org/techniques/T1574/007), [Path Interception by Search Order Hijacking](https://attack.mitre.org/techniques/T1574/008), and/or [Path Interception by Unquoted Path](https://attack.mitre.org/techniques/T1574/009).**
comment: **This technique has been deprecated. Please use [Path Interception by PATH Environment Variable](https://attack.mitre.org/techniques/T1574/007), [Path Interception by Search Order Hijacking](https://attack.mitre.org/techniques/T1574/008), and/or [Path Interception by Unquoted Path](https://attack.mitre.org/techniques/T1574/009).**
deprecated: true

Service Execution
type: Class
subclass of: Execution Technique
attack-id: T1035
definition: Adversaries may execute a binary, command, or script via a method that interacts with Windows services, such as the Service Control Manager. This can be done by either creating a new service or modifying an existing service. This technique is the execution used in conjunction with [New Service](https://attack.mitre.org/techniques/T1050) and [Modify Existing Service](https://attack.mitre.org/techniques/T1031) during service persistence or privilege escalation.
comment: This technique has been revoked by T1569.002
deprecated: true

Masquerading
type: Class
subclass of: Defense Evasion Technique
attack-id: T1036
definition: Adversaries may attempt to manipulate features of their artifacts to make them appear legitimate or benign to users and/or security tools. Masquerading occurs when the name or location of an object, legitimate or malicious, is manipulated or abused for the sake of evading defenses and observation. This may include manipulating file metadata, tricking users into misidentifying the file type, and giving legitimate task or service names.

Invalid Code Signature
type: Class
subclass of: Masquerading
subclass of: Restriction
  on property: creates
  some values from: Executable Binary
type: NamedIndividual
creates: Executable Binary
attack-id: T1036.001
definition: Adversaries may attempt to mimic features of valid code signatures to increase the chance of deceiving a user, analyst, or tool. Code signing provides a level of authenticity on a binary from the developer and a guarantee that the binary has not been tampered with. Adversaries can copy the metadata and signature information from a signed program, then use it as a template for an unsigned program. Files with invalid code signatures will fail digital signature validation checks, but they may appear more legitimate to users and security tools may improperly handle these files.(Citation: Threatexpress MetaTwin 2017)

Right-to-Left Override
type: Class
subclass of: Masquerading
subclass of: Restriction
  on property: modifies
  some values from: File System Metadata
type: NamedIndividual
modifies: File System Metadata
attack-id: T1036.002
definition: Adversaries may abuse the right-to-left override (RTLO or RLO) character (U+202E) to disguise a string and/or file name to make it appear benign. RTLO is a non-printing Unicode character that causes the text that follows it to be displayed in reverse. For example, a Windows screensaver executable named March 25 xcod.scr will display as March 25 rcs.docx. A JavaScript file named photo_high_regnp.js will be displayed as photo_high_resj.png.(Citation: Infosecinstitute RTLO Technique)

Rename System Utilities
type: Class
subclass of: Masquerading
subclass of: Restriction
  on property: may-create
  some values from: Executable File
subclass of: Restriction
  on property: may-modify
  some values from: Operating System Executable File
type: NamedIndividual
may-create: Executable File
may-modify: Operating System Executable File
attack-id: T1036.003
definition: Adversaries may rename legitimate system utilities to try to evade security mechanisms concerning the usage of those utilities. Security monitoring and control mechanisms may be in place for system utilities adversaries are capable of abusing. (Citation: LOLBAS Main Site) It may be possible to bypass those security mechanisms by renaming the utility prior to utilization (ex: rename rundll32.exe). (Citation: Elastic Masquerade Ball) An alternative case occurs when a legitimate utility is copied or moved to a different directory and renamed to avoid detections based on system utilities executing from non-standard paths. (Citation: F-Secure CozyDuke)

Masquerade Task or Service
type: Class
subclass of: Masquerading
subclass of: Restriction
  on property: modifies
  some values from: Job Schedule
type: NamedIndividual
modifies: Job Schedule
attack-id: T1036.004
definition: Adversaries may attempt to manipulate the name of a task or service to make it appear legitimate or benign. Tasks/services executed by the Task Scheduler or systemd will typically be given a name and/or description.(Citation: TechNet Schtasks)(Citation: Systemd Service Units) Windows services will have a service name as well as a display name. Many benign tasks and services exist that have commonly associated names. Adversaries may give tasks or services names that are similar or identical to those of legitimate ones.

Match Legitimate Name or Location
type: Class
subclass of: Masquerading
subclass of: Restriction
  on property: invokes
  some values from: Move File
subclass of: Restriction
  on property: may-create
  some values from: File
type: NamedIndividual
invokes: Move File
may-create: File
attack-id: T1036.005
definition: Adversaries may match or approximate the name or location of legitimate files or resources when naming/placing them. This is done for the sake of evading defenses and observation. This may be done by placing an executable in a commonly trusted directory (ex: under System32) or giving it the name of a legitimate, trusted program (ex: svchost.exe). In containerized environments, this may also be done by creating a resource in a namespace that matches the naming convention of a container pod or cluster. Alternatively, a file or container image name given may be a close approximation to legitimate programs/images or something innocuous.

Space after Filename
type: Class
subclass of: Masquerading
subclass of: Restriction
  on property: creates
  some values from: File
type: NamedIndividual
creates: File
attack-id: T1036.006
definition: Adversaries can hide a program's true filetype by changing the extension of a file. With certain file types (specifically this does not work with .app extensions), appending a space to the end of a filename will change how the file is processed by the operating system.

Double File Extension
type: Class
subclass of: Masquerading
subclass of: Restriction
  on property: modifies
  some values from: File System Metadata
type: NamedIndividual
modifies: File System Metadata
attack-id: T1036.007
definition: Adversaries may abuse a double extension in the filename as a means of masquerading the true file type. A file name may include a secondary file type extension that may cause only the first extension to be displayed (ex: File.txt.exe may render in some views as just File.txt). However, the second extension is the true file type that determines how the file is opened and executed. The real file extension may be hidden by the operating system in the file browser (ex: explorer.exe), as well as in any software configured using or similar to the system’s policies.(Citation: PCMag DoubleExtension)(Citation: SOCPrime DoubleExtension)

Masquerade File Type
type: Class
subclass of: Masquerading
attack-id: T1036.008
definition: Adversaries may masquerade malicious payloads as legitimate files through changes to the payload's formatting, including the file’s signature, extension, and contents. Various file types have a typical standard format, including how they are encoded and organized. For example, a file’s signature (also known as header or magic bytes) is the beginning bytes of a file and is often used to identify the file’s type. For example, the header of a JPEG file, is 0xFF 0xD8 and the file extension is either `.JPE`, `.JPEG` or `.JPG`.

Break Process Trees
type: Class
subclass of: Masquerading
attack-id: T1036.009
definition: An adversary may attempt to evade process tree-based analysis by modifying executed malware's parent process ID (PPID). If endpoint protection software leverages the “parent-child" relationship for detection, breaking this relationship could result in the adversary’s behavior not being associated with previous process tree activity. On Unix-based systems breaking this process tree is common practice for administrators to execute software using scripts and programs.(Citation: 3OHA double-fork 2022)

Masquerade Account Name
type: Class
subclass of: Masquerading
attack-id: T1036.010
definition: Adversaries may match or approximate the names of legitimate accounts to make newly created ones appear benign. This will typically occur during [Create Account](https://attack.mitre.org/techniques/T1136), although accounts may also be renamed at a later date. This may also coincide with [Account Access Removal](https://attack.mitre.org/techniques/T1531) if the actor first deletes an account before re-creating one with the same name.(Citation: Huntress MOVEit 2023)

Boot or Logon Initialization Scripts
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1037
definition: Adversaries may use scripts automatically executed at boot or logon initialization to establish persistence.(Citation: Mandiant APT29 Eye Spy Email Nov 22)(Citation: Anomali Rocke March 2019) Initialization scripts can be used to perform administrative functions, which may often execute other programs or send information to an internal logging server. These scripts can vary based on operating system and whether applied locally or remotely.

Logon Script (Windows)
type: Class
subclass of: Boot or Logon Initialization Scripts
subclass of: Restriction
  on property: modifies
  some values from: User Init Script
type: NamedIndividual
modifies: User Init Script
attack-id: T1037.001
definition: Adversaries may use Windows logon scripts automatically executed at logon initialization to establish persistence. Windows allows logon scripts to be run whenever a specific user or group of users log into a system.(Citation: TechNet Logon Scripts) This is done via adding a path to a script to the HKCU\Environment\UserInitMprLogonScript Registry key.(Citation: Hexacorn Logon Scripts)

Login Hook
type: Class
subclass of: Boot or Logon Initialization Scripts
subclass of: Restriction
  on property: modifies
  some values from: User Init Script
type: NamedIndividual
modifies: User Init Script
attack-id: T1037.002
definition: Adversaries may use a Login Hook to establish persistence executed upon user logon. A login hook is a plist file that points to a specific script to execute with root privileges upon user logon. The plist file is located in the /Library/Preferences/com.apple.loginwindow.plist file and can be modified using the defaults command-line utility. This behavior is the same for logout hooks where a script can be executed upon user logout. All hooks require administrator permissions to modify or create hooks.(Citation: Login Scripts Apple Dev)(Citation: LoginWindowScripts Apple Dev)

Network Logon Script
type: Class
subclass of: Boot or Logon Initialization Scripts
subclass of: Restriction
  on property: modifies
  some values from: Network Init Script File Resource
type: NamedIndividual
modifies: Network Init Script File Resource
attack-id: T1037.003
definition: Group Policy Object / Active Directory Users and Computers are both Active Directory-based

RC Scripts
type: Class
subclass of: Boot or Logon Initialization Scripts
subclass of: Restriction
  on property: modifies
  some values from: System Init Script
type: NamedIndividual
modifies: System Init Script
attack-id: T1037.004
definition: Adversaries may establish persistence by modifying RC scripts which are executed during a Unix-like system’s startup. These files allow system administrators to map and start custom services at startup for different run levels. RC scripts require root privileges to modify.

Startup Items
type: Class
subclass of: Boot or Logon Initialization Scripts
subclass of: Restriction
  on property: modifies
  some values from: System Startup Directory
type: NamedIndividual
modifies: System Startup Directory
attack-id: T1037.005
definition: Adversaries may use startup items automatically executed at boot initialization to establish persistence. Startup items execute during the final phase of the boot process and contain shell scripts or other executable files along with configuration information used by the system to determine the execution order for all startup items.(Citation: Startup Items)

DLL Search Order Hijacking
type: Class
subclass of: Defense Evasion Technique
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1038
definition: Windows systems use a common method to look for required DLLs to load into a program. (Citation: Microsoft DLL Search) Adversaries may take advantage of the Windows DLL search order and programs that ambiguously specify DLLs to gain privilege escalation and persistence.
comment: This technique has been revoked by T1574.001
deprecated: true

Data from Network Shared Drive
type: Class
subclass of: Collection Technique
subclass of: Restriction
  on property: accesses
  some values from: Network File Share Resource
type: NamedIndividual
accesses: Network File Share Resource
attack-id: T1039
definition: Adversaries may search network shares on computers they have compromised to find files of interest. Sensitive data can be collected from remote systems via shared network drives (host shared directory, network file server, etc.) that are accessible from the current system prior to Exfiltration. Interactive command shells may be in use, and common functionality within [cmd](https://attack.mitre.org/software/S0106) may be used to gather information.

Network Sniffing
type: Class
subclass of: Credential Access Technique
subclass of: Discovery Technique
subclass of: Restriction
  on property: may-produce
  some values from: DNS Lookup
type: NamedIndividual
may-produce: DNS Lookup
attack-id: T1040
definition: Adversaries may passively sniff network traffic to capture information about an environment, including authentication material passed over the network. Network sniffing refers to using the network interface on a system to monitor or capture information sent over a wired or wireless connection. An adversary may place a network interface into promiscuous mode to passively access data in transit over the network, or use span ports to capture a larger amount of data.

Exfiltration Over C2 Channel
type: Class
subclass of: Exfiltration Technique
subclass of: Restriction
  on property: may-transfer
  some values from: Certificate File
subclass of: Restriction
  on property: produces
  some values from: Internet Network Traffic
type: NamedIndividual
may-transfer: Certificate File
produces: Internet Network Traffic
attack-id: T1041
definition: Adversaries may steal data by exfiltrating it over an existing command and control channel. Stolen data is encoded into the normal communications channel using the same protocol as command and control communications.

Change Default File Association
type: Class
subclass of: Persistence Technique
attack-id: T1042
definition: When a file is opened, the default program used to open the file (also called the file association or handler) is checked. File association selections are stored in the Windows Registry and can be edited by users, administrators, or programs that have Registry access (Citation: Microsoft Change Default Programs) (Citation: Microsoft File Handlers) or by administrators using the built-in assoc utility. (Citation: Microsoft Assoc Oct 2017) Applications can modify the file association for a given file extension to call an arbitrary program when a file with the given extension is opened.
comment: This technique has been revoked by T1546.001
deprecated: true

Commonly Used Port
type: Class
subclass of: Command and Control Technique
attack-id: T1043
definition: **This technique has been deprecated. Please use [Non-Standard Port](https://attack.mitre.org/techniques/T1571) where appropriate.**
comment: **This technique has been deprecated. Please use [Non-Standard Port](https://attack.mitre.org/techniques/T1571) where appropriate.**
deprecated: true

File System Permissions Weakness
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1044
definition: Processes may automatically execute specific binaries as part of their functionality or to perform other actions. If the permissions on the file system directory containing a target binary, or permissions on the binary itself, are improperly set, then the target binary may be overwritten with another binary using user-level permissions and executed by the original process. If the original process and thread are running under a higher permissions level, then the replaced binary will also execute under higher-level permissions, which could include SYSTEM.
comment: This technique has been revoked by T1574.010
deprecated: true

Software Packing
type: Class
subclass of: Defense Evasion Technique
attack-id: T1045
definition: Software packing is a method of compressing or encrypting an executable. Packing an executable changes the file signature in an attempt to avoid signature-based detection. Most decompression techniques decompress the executable code in memory.
comment: This technique has been revoked by T1027.002
deprecated: true

Network Service Discovery
type: Class
subclass of: Discovery Technique
attack-id: T1046
definition: Adversaries may attempt to get a listing of services running on remote hosts and local network infrastructure devices, including those that may be vulnerable to remote software exploitation. Common methods to acquire this information include port and/or vulnerability scans using tools that are brought onto a system.(Citation: CISA AR21-126A FIVEHANDS May 2021)

Windows Management Instrumentation
type: Class
subclass of: Execution Technique
subclass of: Restriction
  on property: may-create
  some values from: Intranet Administrative Network Traffic
subclass of: Restriction
  on property: may-invoke
  some values from: Create Process
type: NamedIndividual
may-create: Intranet Administrative Network Traffic
may-invoke: Create Process
attack-id: T1047
definition: Adversaries may abuse Windows Management Instrumentation (WMI) to execute malicious commands and payloads. WMI is designed for programmers and is the infrastructure for management data and operations on Windows systems.(Citation: WMI 1-3) WMI is an administration feature that provides a uniform environment to access Windows system components.

Exfiltration Over Alternative Protocol
type: Class
subclass of: Exfiltration Technique
subclass of: Restriction
  on property: produces
  some values from: Internet Network Traffic
type: NamedIndividual
produces: Internet Network Traffic
attack-id: T1048
definition: Adversaries may steal data by exfiltrating it over a different protocol than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server.

Exfiltration Over Symmetric Encrypted Non-C2 Protocol
type: Class
subclass of: Exfiltration Over Alternative Protocol
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Encrypted Traffic
type: NamedIndividual
produces: Outbound Internet Encrypted Traffic
attack-id: T1048.001
definition: Adversaries may steal data by exfiltrating it over a symmetrically encrypted network protocol other than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server.

Exfiltration Over Asymmetric Encrypted Non-C2 Protocol
type: Class
subclass of: Exfiltration Over Alternative Protocol
subclass of: Restriction
  on property: may-transfer
  some values from: Certificate File
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Encrypted Traffic
type: NamedIndividual
may-transfer: Certificate File
produces: Outbound Internet Encrypted Traffic
attack-id: T1048.002
definition: Adversaries may steal data by exfiltrating it over an asymmetrically encrypted network protocol other than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server.

Exfiltration Over Unencrypted Non-C2 Protocol
type: Class
subclass of: Exfiltration Over Alternative Protocol
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Network Traffic
type: NamedIndividual
produces: Outbound Internet Network Traffic
attack-id: T1048.003
definition: Adversaries may steal data by exfiltrating it over an un-encrypted network protocol other than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server.(Citation: copy_cmd_cisco)

System Network Connections Discovery
type: Class
subclass of: Discovery Technique
subclass of: Restriction
  on property: may-invoke
  some values from: Get Open Sockets
type: NamedIndividual
may-invoke: Get Open Sockets
attack-id: T1049
definition: Adversaries may attempt to get a listing of network connections to or from the compromised system they are currently accessing or from remote systems by querying for information over the network.

New Service
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1050
definition: When operating systems boot up, they can start programs or applications called services that perform background system functions. (Citation: TechNet Services) A service's configuration information, including the file path to the service's executable, is stored in the Windows Registry.
comment: This technique has been revoked by T1543.003
deprecated: true

Shared Webroot
type: Class
subclass of: Lateral Movement Technique
attack-id: T1051
definition: **This technique has been deprecated and should no longer be used.**
comment: **This technique has been deprecated and should no longer be used.**
deprecated: true

Exfiltration Over Physical Medium
type: Class
subclass of: Exfiltration Technique
attack-id: T1052
definition: Adversaries may attempt to exfiltrate data via a physical medium, such as a removable drive. In certain circumstances, such as an air-gapped network compromise, exfiltration could occur via a physical medium or device introduced by a user. Such media could be an external hard drive, USB drive, cellular phone, MP3 player, or other removable storage and processing device. The physical medium or device could be used as the final exfiltration point or to hop between otherwise disconnected systems.

Exfiltration over USB
type: Class
subclass of: Exfiltration Over Physical Medium
subclass of: Restriction
  on property: modifies
  some values from: Removable Media Device
type: NamedIndividual
modifies: Removable Media Device
attack-id: T1052.001
definition: Adversaries may attempt to exfiltrate data over a USB connected physical device. In certain circumstances, such as an air-gapped network compromise, exfiltration could occur via a USB device introduced by a user. The USB device could be used as the final exfiltration point or to hop between otherwise disconnected systems.

Scheduled Task/Job
type: Class
subclass of: Execution Technique
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
subclass of: Restriction
  on property: executes
  some values from: Scheduled Job
subclass of: Restriction
  on property: invokes
  some values from: Create Process
subclass of: Restriction
  on property: modifies
  some values from: Job Schedule
type: NamedIndividual
executes: Scheduled Job
invokes: Create Process
modifies: Job Schedule
attack-id: T1053
definition: The sub-techniques of this are specific software implementations of scheduling capabilities

At (Linux) Execution
type: Class
subclass of: Scheduled Task/Job
attack-id: T1053.001
definition: Adversaries may abuse the [at](https://attack.mitre.org/software/S0110) utility to perform task scheduling for initial, recurring, or future execution of malicious code. The [at](https://attack.mitre.org/software/S0110) command within Linux operating systems enables administrators to schedule tasks.(Citation: Kifarunix - Task Scheduling in Linux)
comment: This technique has been revoked by T1053.002
deprecated: true

At
type: Class
subclass of: Scheduled Task/Job
attack-id: T1053.002
definition: Adversaries may abuse the [at](https://attack.mitre.org/software/S0110) utility to perform task scheduling for initial or recurring execution of malicious code. The [at](https://attack.mitre.org/software/S0110) utility exists as an executable within Windows, Linux, and macOS for scheduling tasks at a specified time and date. Although deprecated in favor of [Scheduled Task](https://attack.mitre.org/techniques/T1053/005)'s [schtasks](https://attack.mitre.org/software/S0111) in Windows environments, using [at](https://attack.mitre.org/software/S0110) requires that the Task Scheduler service be running, and the user to be logged on as a member of the local Administrators group.

Cron
type: Class
subclass of: Scheduled Task/Job
attack-id: T1053.003
definition: Adversaries may abuse the cron utility to perform task scheduling for initial or recurring execution of malicious code.(Citation: 20 macOS Common Tools and Techniques) The cron utility is a time-based job scheduler for Unix-like operating systems. The crontab file contains the schedule of cron entries to be run and the specified times for execution. Any crontab files are stored in operating system-specific file paths.

Launchd
type: Class
subclass of: Scheduled Task/Job
subclass of: Restriction
  on property: creates
  some values from: Property List File
type: NamedIndividual
creates: Property List File
attack-id: T1053.004
definition: This technique is deprecated due to the inaccurate usage. The report cited did not provide technical detail as to how the malware interacted directly with launchd rather than going through known services. Other system services are used to interact with launchd rather than launchd being used by itself.
comment: This technique is deprecated due to the inaccurate usage. The report cited did not provide technical detail as to how the malware interacted directly with launchd rather than going through known services. Other system services are used to interact with launchd rather than launchd being used by itself.
deprecated: true

Scheduled Task
type: Class
subclass of: Scheduled Task/Job
subclass of: Restriction
  on property: executes
  some values from: Scheduled Job
type: NamedIndividual
executes: Scheduled Job
attack-id: T1053.005
definition: Renamed from ATT&CK to be consistent with at, launchd, cron siblings; name as is looks like parent. Not sure why parent is not just Scheduled Task [Execution[.

Systemd Timers
type: Class
subclass of: Scheduled Task/Job
attack-id: T1053.006
definition: Adversaries may abuse systemd timers to perform task scheduling for initial or recurring execution of malicious code. Systemd timers are unit files with file extension .timer that control services. Timers can be set to run on a calendar event or after a time span relative to a starting point. They can be used as an alternative to [Cron](https://attack.mitre.org/techniques/T1053/003) in Linux environments.(Citation: archlinux Systemd Timers Aug 2020) Systemd timers may be activated remotely via the systemctl command line utility, which operates over [SSH](https://attack.mitre.org/techniques/T1021/004).(Citation: Systemd Remote Control)

Container Orchestration Job
type: Class
subclass of: Scheduled Task/Job
attack-id: T1053.007
definition: Adversaries may abuse task scheduling functionality provided by container orchestration tools such as Kubernetes to schedule deployment of containers configured to execute malicious code. Container orchestration jobs run these automated tasks at a specific date and time, similar to cron jobs on a Linux system. Deployments of this type can also be configured to maintain a quantity of containers over time, automating the process of maintaining persistence within a cluster.

Indicator Blocking
type: Class
subclass of: Defense Evasion Technique
attack-id: T1054
definition: An adversary may attempt to block indicators or events typically captured by sensors from being gathered and analyzed. This could include maliciously redirecting (Citation: Microsoft Lamin Sept 2017) or even disabling host-based sensors, such as Event Tracing for Windows (ETW),(Citation: Microsoft About Event Tracing 2018) by tampering settings that control the collection and flow of event telemetry. (Citation: Medium Event Tracing Tampering 2018) These settings may be stored on the system in configuration files and/or in the Registry as well as being accessible via administrative utilities such as [PowerShell](https://attack.mitre.org/techniques/T1086) or [Windows Management Instrumentation](https://attack.mitre.org/techniques/T1047).
comment: This technique has been revoked by T1562.006
deprecated: true

Process Injection
type: Class
subclass of: Defense Evasion Technique
subclass of: Privilege Escalation Technique
attack-id: T1055
definition: Adversaries may inject code into processes in order to evade process-based defenses as well as possibly elevate privileges. Process injection is a method of executing arbitrary code in the address space of a separate live process. Running code in the context of another process may allow access to the process's memory, system/network resources, and possibly elevated privileges. Execution via process injection may also evade detection from security products since the execution is masked under a legitimate process.

Dynamic-link Library Injection
type: Class
subclass of: Process Injection
subclass of: Restriction
  on property: adds
  some values from: Shared Library File
subclass of: Restriction
  on property: invokes
  some values from: System Call
subclass of: Restriction
  on property: loads
  some values from: Shared Library File
type: NamedIndividual
adds: Shared Library File
invokes: System Call
loads: Shared Library File
attack-id: T1055.001
definition: Adversaries may inject dynamic-link libraries (DLLs) into processes in order to evade process-based defenses as well as possibly elevate privileges. DLL injection is a method of executing arbitrary code in the address space of a separate live process.

Portable Executable Injection
type: Class
subclass of: Process Injection
subclass of: Restriction
  on property: may-add
  some values from: Object File
type: NamedIndividual
may-add: Object File
attack-id: T1055.002
definition: Adversaries may inject portable executables (PE) into processes in order to evade process-based defenses as well as possibly elevate privileges. PE injection is a method of executing arbitrary code in the address space of a separate live process.

Thread Execution Hijacking
type: Class
subclass of: Process Injection
subclass of: Restriction
  on property: invokes
  some values from: System Call
subclass of: Restriction
  on property: may-add
  some values from: Executable Binary
type: NamedIndividual
invokes: System Call
may-add: Executable Binary
attack-id: T1055.003
definition: Adversaries may inject malicious code into hijacked processes in order to evade process-based defenses as well as possibly elevate privileges. Thread Execution Hijacking is a method of executing arbitrary code in the address space of a separate live process.

Asynchronous Procedure Call
type: Class
subclass of: Process Injection
subclass of: Restriction
  on property: may-invoke
  some values from: Create Process
type: NamedIndividual
may-invoke: Create Process
attack-id: T1055.004
definition: Adversaries may inject malicious code into processes via the asynchronous procedure call (APC) queue in order to evade process-based defenses as well as possibly elevate privileges. APC injection is a method of executing arbitrary code in the address space of a separate live process.

Thread Local Storage
type: Class
subclass of: Process Injection
subclass of: Restriction
  on property: invokes
  some values from: System Call
type: NamedIndividual
invokes: System Call
attack-id: T1055.005
definition: Adversaries may inject malicious code into processes via thread local storage (TLS) callbacks in order to evade process-based defenses as well as possibly elevate privileges. TLS callback injection is a method of executing arbitrary code in the address space of a separate live process.

Ptrace System Calls
type: Class
subclass of: Process Injection
subclass of: Restriction
  on property: invokes
  some values from: System Call
type: NamedIndividual
invokes: System Call
attack-id: T1055.008
definition: Adversaries may inject malicious code into processes via ptrace (process trace) system calls in order to evade process-based defenses as well as possibly elevate privileges. Ptrace system call injection is a method of executing arbitrary code in the address space of a separate live process.

Proc Memory
type: Class
subclass of: Process Injection
subclass of: Restriction
  on property: accesses
  some values from: Operating System File
subclass of: Restriction
  on property: may-modify
  some values from: Operating System File
type: NamedIndividual
accesses: Operating System File
may-modify: Operating System File
attack-id: T1055.009
definition: Adversaries may inject malicious code into processes via the /proc filesystem in order to evade process-based defenses as well as possibly elevate privileges. Proc memory injection is a method of executing arbitrary code in the address space of a separate live process.

Extra Window Memory Injection
type: Class
subclass of: Process Injection
attack-id: T1055.011
definition: Adversaries may inject malicious code into process via Extra Window Memory (EWM) in order to evade process-based defenses as well as possibly elevate privileges. EWM injection is a method of executing arbitrary code in the address space of a separate live process.

Process Hollowing
type: Class
subclass of: Process Injection
subclass of: Restriction
  on property: modifies
  some values from: Process Code Segment
type: NamedIndividual
modifies: Process Code Segment
attack-id: T1055.012
definition: Adversaries may inject malicious code into suspended and hollowed processes in order to evade process-based defenses. Process hollowing is a method of executing arbitrary code in the address space of a separate live process.

Process Doppelgänging
type: Class
subclass of: Process Injection
subclass of: Restriction
  on property: invokes
  some values from: Create Process
type: NamedIndividual
invokes: Create Process
attack-id: T1055.013
definition: Adversaries may inject malicious code into process via process doppelgänging in order to evade process-based defenses as well as possibly elevate privileges. Process doppelgänging is a method of executing arbitrary code in the address space of a separate live process.

VDSO Hijacking
type: Class
subclass of: Process Injection
subclass of: Restriction
  on property: accesses
  some values from: Shared Library File
subclass of: Restriction
  on property: invokes
  some values from: System Call
type: NamedIndividual
accesses: Shared Library File
invokes: System Call
attack-id: T1055.014
definition: Adversaries may inject malicious code into processes via VDSO hijacking in order to evade process-based defenses as well as possibly elevate privileges. Virtual dynamic shared object (vdso) hijacking is a method of executing arbitrary code in the address space of a separate live process.

ListPlanting
type: Class
subclass of: Process Injection
attack-id: T1055.015
definition: Adversaries may abuse list-view controls to inject malicious code into hijacked processes in order to evade process-based defenses as well as possibly elevate privileges. ListPlanting is a method of executing arbitrary code in the address space of a separate live process. Code executed via ListPlanting may also evade detection from security products since the execution is masked under a legitimate process.

Input Capture
type: Class
subclass of: Collection Technique
subclass of: Credential Access Technique
attack-id: T1056
definition: Adversaries may use methods of capturing user input to obtain credentials or collect information. During normal system usage, users often provide credentials to various different locations, such as login pages/portals or system dialog boxes. Input capture mechanisms may be transparent to the user (e.g. [Credential API Hooking](https://attack.mitre.org/techniques/T1056/004)) or rely on deceiving the user into providing input into what they believe to be a genuine service (e.g. [Web Portal Capture](https://attack.mitre.org/techniques/T1056/003)).

Keylogging
type: Class
subclass of: Input Capture
subclass of: Restriction
  on property: accesses
  some values from: Keyboard Input Device
type: NamedIndividual
accesses: Keyboard Input Device
attack-id: T1056.001
definition: Adversaries may log user keystrokes to intercept credentials as the user types them. Keylogging is likely to be used to acquire credentials for new access opportunities when [OS Credential Dumping](https://attack.mitre.org/techniques/T1003) efforts are not effective, and may require an adversary to intercept keystrokes on a system for a substantial period of time before credentials can be successfully captured. In order to increase the likelihood of capturing credentials quickly, an adversary may also perform actions such as clearing browser cookies to force users to reauthenticate to systems.(Citation: Talos Kimsuky Nov 2021)

GUI Input Capture
type: Class
subclass of: Input Capture
subclass of: Restriction
  on property: accesses
  some values from: Graphical User Interface
type: NamedIndividual
accesses: Graphical User Interface
attack-id: T1056.002
definition: Adversaries may mimic common operating system GUI components to prompt users for credentials with a seemingly legitimate prompt. When programs are executed that need additional privileges than are present in the current user context, it is common for the operating system to prompt the user for proper credentials to authorize the elevated privileges for the task (ex: [Bypass User Account Control](https://attack.mitre.org/techniques/T1548/002)).

Web Portal Capture
type: Class
subclass of: Input Capture
subclass of: Restriction
  on property: modifies
  some values from: Web Server Application
type: NamedIndividual
modifies: Web Server Application
attack-id: T1056.003
definition: Adversaries may install code on externally facing portals, such as a VPN login page, to capture and transmit credentials of users who attempt to log into the service. For example, a compromised login page may log provided user credentials before logging the user in to the service.

Credential API Hooking
type: Class
subclass of: Input Capture
subclass of: Restriction
  on property: may-modify
  some values from: Process Code Segment
type: NamedIndividual
may-modify: Process Code Segment
attack-id: T1056.004
definition: Adversaries may hook into Windows application programming interface (API) functions to collect user credentials. Malicious hooking mechanisms may capture API calls that include parameters that reveal user authentication credentials.(Citation: Microsoft TrojanSpy:Win32/Ursnif.gen!I Sept 2017) Unlike [Keylogging](https://attack.mitre.org/techniques/T1056/001), this technique focuses specifically on API functions that include parameters that reveal user credentials. Hooking involves redirecting calls to these functions and can be implemented via:

Process Discovery
type: Class
subclass of: Discovery Technique
subclass of: Restriction
  on property: may-invoke
  some values from: Create Process
subclass of: Restriction
  on property: may-invoke
  some values from: Get Running Processes
type: NamedIndividual
may-invoke: Create Process
may-invoke: Get Running Processes
attack-id: T1057
definition: Adversaries may attempt to get information about running processes on a system. Information obtained could be used to gain an understanding of common software/applications running on systems within the network. Administrator or otherwise elevated access may provide better process details. Adversaries may use the information from [Process Discovery](https://attack.mitre.org/techniques/T1057) during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.

Service Registry Permissions Weakness
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1058
definition: Windows stores local service configuration information in the Registry under HKLM\SYSTEM\CurrentControlSet\Services. The information stored under a service's Registry keys can be manipulated to modify a service's execution parameters through tools such as the service controller, sc.exe, [PowerShell](https://attack.mitre.org/techniques/T1086), or [Reg](https://attack.mitre.org/software/S0075). Access to Registry keys is controlled through Access Control Lists and permissions. (Citation: MSDN Registry Key Security)
comment: This technique has been revoked by T1574.011
deprecated: true

Command and Scripting Interpreter
type: Class
subclass of: Execution Technique
subclass of: Restriction
  on property: executes
  some values from: Executable Script
type: NamedIndividual
executes: Executable Script
attack-id: T1059
definition: Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries. These interfaces and languages provide ways of interacting with computer systems and are a common feature across many different platforms. Most systems come with some built-in command-line interface and scripting capabilities, for example, macOS and Linux distributions include some flavor of [Unix Shell](https://attack.mitre.org/techniques/T1059/004) while Windows installations include the [Windows Command Shell](https://attack.mitre.org/techniques/T1059/003) and [PowerShell](https://attack.mitre.org/techniques/T1059/001).

PowerShell
type: Class
subclass of: Command and Scripting Interpreter
attack-id: T1059.001
definition: Adversaries may abuse PowerShell commands and scripts for execution. PowerShell is a powerful interactive command-line interface and scripting environment included in the Windows operating system.(Citation: TechNet PowerShell) Adversaries can use PowerShell to perform a number of actions, including discovery of information and execution of code. Examples include the Start-Process cmdlet which can be used to run an executable and the Invoke-Command cmdlet which runs a command locally or on a remote computer (though administrator permissions are required to use PowerShell to connect to remote systems).

AppleScript
type: Class
subclass of: Command and Scripting Interpreter
attack-id: T1059.002
definition: Adversaries may abuse AppleScript for execution. AppleScript is a macOS scripting language designed to control applications and parts of the OS via inter-application messages called AppleEvents.(Citation: Apple AppleScript) These AppleEvent messages can be sent independently or easily scripted with AppleScript. These events can locate open windows, send keystrokes, and interact with almost any open application locally or remotely.

Windows Command Shell
type: Class
subclass of: Command and Scripting Interpreter
attack-id: T1059.003
definition: Adversaries may abuse the Windows command shell for execution. The Windows command shell ([cmd](https://attack.mitre.org/software/S0106)) is the primary command prompt on Windows systems. The Windows command prompt can be used to control almost any aspect of a system, with various permission levels required for different subsets of commands. The command prompt can be invoked remotely via [Remote Services](https://attack.mitre.org/techniques/T1021) such as [SSH](https://attack.mitre.org/techniques/T1021/004).(Citation: SSH in Windows)

Unix Shell
type: Class
subclass of: Command and Scripting Interpreter
attack-id: T1059.004
definition: Adversaries may abuse Unix shell commands and scripts for execution. Unix shells are the primary command prompt on Linux and macOS systems, though many variations of the Unix shell exist (e.g. sh, bash, zsh, etc.) depending on the specific OS or distribution.(Citation: DieNet Bash)(Citation: Apple ZShell) Unix shells can control every aspect of a system, with certain commands requiring elevated privileges.
alternative label: Bash Execution

Visual Basic
type: Class
subclass of: Command and Scripting Interpreter
attack-id: T1059.005
definition: Adversaries may abuse Visual Basic (VB) for execution. VB is a programming language created by Microsoft with interoperability with many Windows technologies such as [Component Object Model](https://attack.mitre.org/techniques/T1559/001) and the [Native API](https://attack.mitre.org/techniques/T1106) through the Windows API. Although tagged as legacy with no planned future evolutions, VB is integrated and supported in the .NET Framework and cross-platform .NET Core.(Citation: VB .NET Mar 2020)(Citation: VB Microsoft)

Python
type: Class
subclass of: Command and Scripting Interpreter
attack-id: T1059.006
definition: Adversaries may abuse Python commands and scripts for execution. Python is a very popular scripting/programming language, with capabilities to perform many functions. Python can be executed interactively from the command-line (via the python.exe interpreter) or via scripts (.py) that can be written and distributed to different systems. Python code can also be compiled into binary executables.(Citation: Zscaler APT31 Covid-19 October 2020)

JavaScript
type: Class
subclass of: Command and Scripting Interpreter
attack-id: T1059.007
definition: Adversaries may abuse various implementations of JavaScript for execution. JavaScript (JS) is a platform-independent scripting language (compiled just-in-time at runtime) commonly associated with scripts in webpages, though JS can be executed in runtime environments outside the browser.(Citation: NodeJS)

Network Device CLI
type: Class
subclass of: Command and Scripting Interpreter
attack-id: T1059.008
definition: Adversaries may abuse scripting or built-in command line interpreters (CLI) on network devices to execute malicious command and payloads. The CLI is the primary means through which users and administrators interact with the device in order to view system information, modify device operations, or perform diagnostic and administrative functions. CLIs typically contain various permission levels required for different commands.

Cloud API
type: Class
subclass of: Command and Scripting Interpreter
attack-id: T1059.009
definition: Adversaries may abuse cloud APIs to execute malicious commands. APIs available in cloud environments provide various functionalities and are a feature-rich method for programmatic access to nearly all aspects of a tenant. These APIs may be utilized through various methods such as command line interpreters (CLIs), in-browser Cloud Shells, [PowerShell](https://attack.mitre.org/techniques/T1059/001) modules like Azure for PowerShell(Citation: Microsoft - Azure PowerShell), or software developer kits (SDKs) available for languages such as [Python](https://attack.mitre.org/techniques/T1059/006).

AutoHotKey & AutoIT
type: Class
subclass of: Command and Scripting Interpreter
attack-id: T1059.010
definition: Adversaries may execute commands and perform malicious tasks using AutoIT and AutoHotKey automation scripts. AutoIT and AutoHotkey (AHK) are scripting languages that enable users to automate Windows tasks. These automation scripts can be used to perform a wide variety of actions, such as clicking on buttons, entering text, and opening and closing programs.(Citation: AutoIT)(Citation: AutoHotKey)

Lua
type: Class
subclass of: Command and Scripting Interpreter
attack-id: T1059.011
definition: Adversaries may abuse Lua commands and scripts for execution. Lua is a cross-platform scripting and programming language primarily designed for embedded use in applications. Lua can be executed on the command-line (through the stand-alone lua interpreter), via scripts (.lua), or from Lua-embedded programs (through the struct lua_State).(Citation: Lua main page)(Citation: Lua state)

Registry Run Keys / Startup Folder
type: Class
subclass of: Persistence Technique
attack-id: T1060
definition: Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key. Adding an entry to the "run keys" in the Registry or startup folder will cause the program referenced to be executed when a user logs in. (Citation: Microsoft Run Key) These programs will be executed under the context of the user and will have the account's associated permissions level.
comment: This technique has been revoked by T1547.001
deprecated: true

Graphical User Interface
type: Class
subclass of: Execution Technique
attack-id: T1061
definition: **This technique has been deprecated. Please use [Remote Services](https://attack.mitre.org/techniques/T1021) where appropriate.**
comment: **This technique has been deprecated. Please use [Remote Services](https://attack.mitre.org/techniques/T1021) where appropriate.**
deprecated: true

Hypervisor
type: Class
subclass of: Persistence Technique
attack-id: T1062
definition: **This technique has been deprecated and should no longer be used.**
comment: **This technique has been deprecated and should no longer be used.**
deprecated: true

Security Software Discovery
type: Class
subclass of: Discovery Technique
attack-id: T1063
definition: Adversaries may attempt to get a listing of security software, configurations, defensive tools, and sensors that are installed on the system. This may include things such as local firewall rules and anti-virus. Adversaries may use the information from [Security Software Discovery](https://attack.mitre.org/techniques/T1063) during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.
comment: This technique has been revoked by T1518.001
deprecated: true

Scripting
type: Class
subclass of: Defense Evasion Technique
subclass of: Execution Technique
attack-id: T1064
definition: **This technique has been deprecated. Please use [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059) where appropriate.**
comment: **This technique has been deprecated. Please use [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059) where appropriate.**
deprecated: true

Uncommonly Used Port
type: Class
subclass of: Command and Control Technique
attack-id: T1065
definition: Adversaries may conduct C2 communications over a non-standard port to bypass proxies and firewalls that have been improperly configured.
comment: This technique has been revoked by T1571
deprecated: true

Indicator Removal from Tools
type: Class
subclass of: Defense Evasion Technique
attack-id: T1066
definition: If a malicious tool is detected and quarantined or otherwise curtailed, an adversary may be able to determine why the malicious tool was detected (the indicator), modify the tool by removing the indicator, and use the updated version that is no longer detected by the target's defensive systems or subsequent targets that may use similar systems.
comment: This technique has been revoked by T1027.005
deprecated: true

Bootkit
type: Class
subclass of: Persistence Technique
attack-id: T1067
definition: A bootkit is a malware variant that modifies the boot sectors of a hard drive, including the Master Boot Record (MBR) and Volume Boot Record (VBR). (Citation: MTrends 2016)
comment: This technique has been revoked by T1542.003
deprecated: true

Exploitation for Privilege Escalation
type: Class
subclass of: Privilege Escalation Technique
subclass of: Restriction
  on property: enables
  some values from: Privilege Escalation
subclass of: Restriction
  on property: may-modify
  some values from: Stack Frame
subclass of: Restriction
  on property: modifies
  some values from: Process Code Segment
type: NamedIndividual
enables: Privilege Escalation
may-modify: Stack Frame
modifies: Process Code Segment
attack-id: T1068
definition: Adversaries may exploit software vulnerabilities in an attempt to elevate privileges. Exploitation of a software vulnerability occurs when an adversary takes advantage of a programming error in a program, service, or within the operating system software or kernel itself to execute adversary-controlled code. Security constructs such as permission levels will often hinder access to information and use of certain techniques, so adversaries will likely need to perform privilege escalation to include use of software exploitation to circumvent those restrictions.

Permission Groups Discovery
type: Class
subclass of: Discovery Technique
attack-id: T1069
definition: Adversaries may attempt to discover group and permission settings. This information can help adversaries determine which user accounts and groups are available, the membership of users in particular groups, and which users and groups have elevated permissions.

Local Groups
type: Class
subclass of: Permission Groups Discovery
attack-id: T1069.001
definition: Adversaries may attempt to find local system groups and permission settings. The knowledge of local system permission groups can help adversaries determine which groups exist and which users belong to a particular group. Adversaries may use this information to determine which users have elevated permissions, such as the users found within the local administrators group.

Domain Groups
type: Class
subclass of: Permission Groups Discovery
attack-id: T1069.002
definition: Adversaries may attempt to find domain-level groups and permission settings. The knowledge of domain-level permission groups can help adversaries determine which groups exist and which users belong to a particular group. Adversaries may use this information to determine which users have elevated permissions, such as domain administrators.

Cloud Groups
type: Class
subclass of: Permission Groups Discovery
attack-id: T1069.003
definition: Adversaries may attempt to find cloud groups and permission settings. The knowledge of cloud permission groups can help adversaries determine the particular roles of users and groups within an environment, as well as which users are associated with a particular group.

Indicator Removal
type: Class
subclass of: Defense Evasion Technique
attack-id: T1070
definition: Adversaries may delete or modify artifacts generated within systems to remove evidence of their presence or hinder defenses. Various artifacts may be created by an adversary or something that can be attributed to an adversary’s actions. Typically these artifacts are used as defensive indicators related to monitored events, such as strings from downloaded files, logs that are generated from user actions, and other data analyzed by defenders. Location, format, and type of artifact (such as command or login history) are often specific to each platform.

Clear Windows Event Logs
type: Class
subclass of: Indicator Removal
subclass of: Restriction
  on property: modifies
  some values from: Event Log
type: NamedIndividual
modifies: Event Log
attack-id: T1070.001
definition: Adversaries may clear Windows Event Logs to hide the activity of an intrusion. Windows Event Logs are a record of a computer's alerts and notifications. There are three system-defined sources of events: System, Application, and Security, with five event types: Error, Warning, Information, Success Audit, and Failure Audit.

Clear Linux or Mac System Logs
type: Class
subclass of: Indicator Removal
subclass of: Restriction
  on property: modifies
  some values from: Operating System Log File
type: NamedIndividual
modifies: Operating System Log File
attack-id: T1070.002
definition: Adversaries may clear system logs to hide evidence of an intrusion. macOS and Linux both keep track of system or user-initiated actions via system logs. The majority of native system logging is stored under the /var/log/ directory. Subfolders in this directory categorize logs by their related functions, such as:(Citation: Linux Logs)

Clear Command History
type: Class
subclass of: Indicator Removal
subclass of: Restriction
  on property: modifies
  some values from: Command History Log
type: NamedIndividual
modifies: Command History Log
attack-id: T1070.003
definition: In addition to clearing system logs, an adversary may clear the command history of a compromised account to conceal the actions undertaken during an intrusion. Various command interpreters keep track of the commands users type in their terminal so that users can retrace what they've done.

File Deletion
type: Class
subclass of: Indicator Removal
subclass of: Restriction
  on property: deletes
  some values from: File
subclass of: Restriction
  on property: may-modify
  some values from: File
type: NamedIndividual
deletes: File
may-modify: File
attack-id: T1070.004
definition: Adversaries may delete files left behind by the actions of their intrusion activity. Malware, tools, or other non-native files dropped or created on a system by an adversary (ex: [Ingress Tool Transfer](https://attack.mitre.org/techniques/T1105)) may leave traces to indicate to what was done within a network and how. Removal of these files can occur during an intrusion, or as part of a post-intrusion process to minimize the adversary's footprint.

Network Share Connection Removal
type: Class
subclass of: Indicator Removal
subclass of: Restriction
  on property: unmounts
  some values from: Network File Share Resource
type: NamedIndividual
unmounts: Network File Share Resource
attack-id: T1070.005
definition: Adversaries may remove share connections that are no longer useful in order to clean up traces of their operation. Windows shared drive and [SMB/Windows Admin Shares](https://attack.mitre.org/techniques/T1021/002) connections can be removed when no longer needed. [Net](https://attack.mitre.org/software/S0039) is an example utility that can be used to remove network share connections with the net use \\system\share /delete command. (Citation: Technet Net Use)

Timestomp
type: Class
subclass of: Indicator Removal
subclass of: Restriction
  on property: forges
  some values from: File System Metadata
type: NamedIndividual
forges: File System Metadata
attack-id: T1070.006
definition: Adversaries may modify file time attributes to hide new or changes to existing files. Timestomping is a technique that modifies the timestamps of a file (the modify, access, create, and change times), often to mimic files that are in the same folder. This is done, for example, on files that have been modified or created by the adversary so that they do not appear conspicuous to forensic investigators or file analysis tools.

Clear Network Connection History and Configurations
type: Class
subclass of: Indicator Removal
attack-id: T1070.007
definition: Adversaries may clear or remove evidence of malicious network connections in order to clean up traces of their operations. Configuration settings as well as various artifacts that highlight connection history may be created on a system and/or in application logs from behaviors that require network connections, such as [Remote Services](https://attack.mitre.org/techniques/T1021) or [External Remote Services](https://attack.mitre.org/techniques/T1133). Defenders may use these artifacts to monitor or otherwise analyze network connections created by adversaries.

Clear Mailbox Data
type: Class
subclass of: Indicator Removal
attack-id: T1070.008
definition: Adversaries may modify mail and mail application data to remove evidence of their activity. Email applications allow users and other programs to export and delete mailbox data via command line tools or use of APIs. Mail application data can be emails, email metadata, or logs generated by the application or operating system, such as export requests.

Clear Persistence
type: Class
subclass of: Indicator Removal
attack-id: T1070.009
definition: Adversaries may clear artifacts associated with previously established persistence on a host system to remove evidence of their activity. This may involve various actions, such as removing services, deleting executables, [Modify Registry](https://attack.mitre.org/techniques/T1112), [Plist File Modification](https://attack.mitre.org/techniques/T1647), or other methods of cleanup to prevent defenders from collecting evidence of their persistent presence.(Citation: Cylance Dust Storm) Adversaries may also delete accounts previously created to maintain persistence (i.e. [Create Account](https://attack.mitre.org/techniques/T1136)).(Citation: Talos - Cisco Attack 2022)

Relocate Malware
type: Class
subclass of: Indicator Removal
attack-id: T1070.010
definition: Once a payload is delivered, adversaries may reproduce copies of the same malware on the victim system to remove evidence of their presence and/or avoid defenses. Copying malware payloads to new locations may also be combined with [File Deletion](https://attack.mitre.org/techniques/T1070/004) to cleanup older artifacts.

Application Layer Protocol
type: Class
subclass of: Command and Control Technique
subclass of: Restriction
  on property: may-transfer
  some values from: Certificate File
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Network Traffic
type: NamedIndividual
may-transfer: Certificate File
produces: Outbound Internet Network Traffic
attack-id: T1071
definition: Adversaries may communicate using OSI application layer protocols to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.
pref-label: Application Layer Protocol C2

Web Protocols
type: Class
subclass of: Application Layer Protocol
subclass of: Restriction
  on property: may-transfer
  some values from: Certificate File
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Web Traffic
type: NamedIndividual
may-transfer: Certificate File
produces: Outbound Internet Web Traffic
attack-id: T1071.001
definition: Adversaries may communicate using application layer protocols associated with web traffic to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.

File Transfer Protocols
type: Class
subclass of: Application Layer Protocol
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet File Transfer Traffic
type: NamedIndividual
produces: Outbound Internet File Transfer Traffic
attack-id: T1071.002
definition: Adversaries may communicate using application layer protocols associated with transferring files to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.

Mail Protocols
type: Class
subclass of: Application Layer Protocol
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Mail Traffic
type: NamedIndividual
produces: Outbound Internet Mail Traffic
attack-id: T1071.003
definition: Adversaries may communicate using application layer protocols associated with electronic mail delivery to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.

DNS
type: Class
subclass of: Application Layer Protocol
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet DNS Lookup Traffic
type: NamedIndividual
produces: Outbound Internet DNS Lookup Traffic
attack-id: T1071.004
definition: Adversaries may communicate using the Domain Name System (DNS) application layer protocol to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.

Publish/Subscribe Protocols
type: Class
subclass of: Application Layer Protocol
attack-id: T1071.005
definition: Adversaries may communicate using publish/subscribe (pub/sub) application layer protocols to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.

Software Deployment Tools
type: Class
subclass of: Execution Technique
subclass of: Lateral Movement Technique
subclass of: Restriction
  on property: adds
  some values from: File
subclass of: Restriction
  on property: executes
  some values from: Software Deployment Tool
subclass of: Restriction
  on property: installs
  some values from: Software
type: NamedIndividual
adds: File
executes: Software Deployment Tool
installs: Software
attack-id: T1072
definition: Adversaries may gain access to and use centralized software suites installed within an enterprise to execute commands and move laterally through the network. Configuration management and software deployment applications may be used in an enterprise network or cloud environment for routine administration purposes. These systems may also be integrated into CI/CD pipelines. Examples of such solutions include: SCCM, HBSS, Altiris, AWS Systems Manager, Microsoft Intune, Azure Arc, and GCP Deployment Manager.

DLL Side-Loading
type: Class
subclass of: Defense Evasion Technique
attack-id: T1073
definition: Programs may specify DLLs that are loaded at runtime. Programs that improperly or vaguely specify a required DLL may be open to a vulnerability in which an unintended DLL is loaded. Side-loading vulnerabilities specifically occur when Windows Side-by-Side (WinSxS) manifests (Citation: MSDN Manifests) are not explicit enough about characteristics of the DLL to be loaded. Adversaries may take advantage of a legitimate program that is vulnerable to side-loading to load a malicious DLL. (Citation: Stewart 2014)
comment: This technique has been revoked by T1574.002
deprecated: true

Data Staged
type: Class
subclass of: Collection Technique
subclass of: Restriction
  on property: reads
  some values from: Resource
type: NamedIndividual
reads: Resource
attack-id: T1074
definition: Adversaries may stage collected data in a central location or directory prior to Exfiltration. Data may be kept in separate files or combined into one file through techniques such as [Archive Collected Data](https://attack.mitre.org/techniques/T1560). Interactive command shells may be used, and common functionality within [cmd](https://attack.mitre.org/software/S0106) and bash may be used to copy data into a staging location.(Citation: PWC Cloud Hopper April 2017)

Local Data Staging
type: Class
subclass of: Data Staged
subclass of: Restriction
  on property: may-create
  some values from: File
subclass of: Restriction
  on property: may-invoke
  some values from: Create File
type: NamedIndividual
may-create: File
may-invoke: Create File
attack-id: T1074.001
definition: Adversaries may stage collected data in a central location or directory on the local system prior to Exfiltration. Data may be kept in separate files or combined into one file through techniques such as [Archive Collected Data](https://attack.mitre.org/techniques/T1560). Interactive command shells may be used, and common functionality within [cmd](https://attack.mitre.org/software/S0106) and bash may be used to copy data into a staging location.

Remote Data Staging
type: Class
subclass of: Data Staged
subclass of: Restriction
  on property: modifies
  some values from: Network Resource
type: NamedIndividual
modifies: Network Resource
attack-id: T1074.002
definition: Adversaries may stage data collected from multiple systems in a central location or directory on one system prior to Exfiltration. Data may be kept in separate files or combined into one file through techniques such as [Archive Collected Data](https://attack.mitre.org/techniques/T1560). Interactive command shells may be used, and common functionality within [cmd](https://attack.mitre.org/software/S0106) and bash may be used to copy data into a staging location.

Pass the Hash
type: Class
subclass of: Lateral Movement Technique
attack-id: T1075
definition: Pass the hash (PtH) is a method of authenticating as a user without having access to the user's cleartext password. This method bypasses standard authentication steps that require a cleartext password, moving directly into the portion of the authentication that uses the password hash. In this technique, valid password hashes for the account being used are captured using a Credential Access technique. Captured hashes are used with PtH to authenticate as that user. Once authenticated, PtH may be used to perform actions on local or remote systems.
comment: This technique has been revoked by T1550.002
deprecated: true

Remote Desktop Protocol
type: Class
subclass of: Lateral Movement Technique
attack-id: T1076
definition: Remote desktop is a common feature in operating systems. It allows a user to log into an interactive session with a system desktop graphical user interface on a remote system. Microsoft refers to its implementation of the Remote Desktop Protocol (RDP) as Remote Desktop Services (RDS). (Citation: TechNet Remote Desktop Services) There are other implementations and third-party tools that provide graphical access [Remote Services](https://attack.mitre.org/techniques/T1021) similar to RDS.
comment: This technique has been revoked by T1021.001
deprecated: true

Windows Admin Shares
type: Class
subclass of: Lateral Movement Technique
attack-id: T1077
definition: Windows systems have hidden network shares that are accessible only to administrators and provide the ability for remote file copy and other administrative functions. Example network shares include C$, ADMIN$, and IPC$.
comment: This technique has been revoked by T1021.002
deprecated: true

Valid Accounts
type: Class
subclass of: Defense Evasion Technique
subclass of: Initial Access Technique
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
subclass of: Restriction
  on property: produces
  some values from: Authentication
subclass of: Restriction
  on property: produces
  some values from: Authorization
subclass of: Restriction
  on property: uses
  some values from: User Account
type: NamedIndividual
produces: Authentication
produces: Authorization
uses: User Account
attack-id: T1078
definition: Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Compromised credentials may be used to bypass access controls placed on various resources on systems within the network and may even be used for persistent access to remote systems and externally available services, such as VPNs, Outlook Web Access, network devices, and remote desktop.(Citation: volexity_0day_sophos_FW) Compromised credentials may also grant an adversary increased privilege to specific systems or access to restricted areas of the network. Adversaries may choose not to use malware or tools in conjunction with the legitimate access those credentials provide to make it harder to detect their presence.

Default Accounts
type: Class
subclass of: Valid Accounts
subclass of: Restriction
  on property: uses
  some values from: Default User Account
type: NamedIndividual
uses: Default User Account
attack-id: T1078.001
definition: Adversaries may obtain and abuse credentials of a default account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Default accounts are those that are built-into an OS, such as the Guest or Administrator accounts on Windows systems. Default accounts also include default factory/provider set accounts on other types of systems, software, or devices, including the root user account in AWS and the default service account in Kubernetes.(Citation: Microsoft Local Accounts Feb 2019)(Citation: AWS Root User)(Citation: Threat Matrix for Kubernetes)

Domain Accounts
type: Class
subclass of: Valid Accounts
subclass of: Restriction
  on property: uses
  some values from: Domain User Account
type: NamedIndividual
uses: Domain User Account
attack-id: T1078.002
definition: Adversaries may obtain and abuse credentials of a domain account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.(Citation: TechNet Credential Theft) Domain accounts are those managed by Active Directory Domain Services where access and permissions are configured across systems and services that are part of that domain. Domain accounts can cover users, administrators, and services.(Citation: Microsoft AD Accounts)

Local Accounts
type: Class
subclass of: Valid Accounts
subclass of: Restriction
  on property: uses
  some values from: Local User Account
type: NamedIndividual
uses: Local User Account
attack-id: T1078.003
definition: Adversaries may obtain and abuse credentials of a local account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Local accounts are those configured by an organization for use by users, remote support, services, or for administration on a single system or service.

Cloud Accounts
type: Class
subclass of: Valid Accounts
subclass of: Restriction
  on property: uses
  some values from: Cloud User Account
type: NamedIndividual
uses: Cloud User Account
attack-id: T1078.004
definition: Valid accounts in cloud environments may allow adversaries to perform actions to achieve Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Cloud accounts are those created and configured by an organization for use by users, remote support, services, or for administration of resources within a cloud service provider or SaaS application. Cloud Accounts can exist solely in the cloud; alternatively, they may be hybrid-joined between on-premises systems and the cloud through syncing or federation with other identity sources such as Windows Active Directory. (Citation: AWS Identity Federation)(Citation: Google Federating GC)(Citation: Microsoft Deploying AD Federation)

Multilayer Encryption
type: Class
subclass of: Command and Control Technique
attack-id: T1079
definition: An adversary performs C2 communications using multiple layers of encryption, typically (but not exclusively) tunneling a custom encryption scheme within a protocol encryption scheme such as HTTPS or SMTPS.
comment: This technique has been revoked by T1573
deprecated: true

Taint Shared Content
type: Class
subclass of: Lateral Movement Technique
subclass of: Restriction
  on property: modifies
  some values from: Network Resource
type: NamedIndividual
modifies: Network Resource
attack-id: T1080

Credentials in Files
type: Class
subclass of: Credential Access Technique
attack-id: T1081
definition: Adversaries may search local file systems and remote file shares for files containing passwords. These can be files created by users to store their own credentials, shared credential stores for a group of individuals, configuration files containing passwords for a system or service, or source code/binary files containing embedded passwords.
comment: This technique has been revoked by T1552.001
deprecated: true

System Information Discovery
type: Class
subclass of: Discovery Technique
subclass of: Restriction
  on property: may-access
  some values from: Decoy Artifact
subclass of: Restriction
  on property: may-invoke
  some values from: Create Process
type: NamedIndividual
may-access: Decoy Artifact
may-invoke: Create Process
attack-id: T1082
definition: An adversary may attempt to get detailed information about the operating system and hardware, including version, patches, hotfixes, service packs, and architecture. Adversaries may use the information from [System Information Discovery](https://attack.mitre.org/techniques/T1082) during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.

File and Directory Discovery
type: Class
subclass of: Discovery Technique
subclass of: Restriction
  on property: accesses
  some values from: Directory
subclass of: Restriction
  on property: accesses
  some values from: File
type: NamedIndividual
accesses: Directory
accesses: File
attack-id: T1083
definition: Adversaries may enumerate files and directories or may search in specific locations of a host or network share for certain information within a file system. Adversaries may use the information from [File and Directory Discovery](https://attack.mitre.org/techniques/T1083) during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.

Windows Management Instrumentation Event Subscription
type: Class
subclass of: Persistence Technique
attack-id: T1084
definition: Windows Management Instrumentation (WMI) can be used to install event filters, providers, consumers, and bindings that execute code when a defined event occurs. Adversaries may use the capabilities of WMI to subscribe to an event and execute arbitrary code when that event occurs, providing persistence on a system. Adversaries may attempt to evade detection of this technique by compiling WMI scripts into Windows Management Object (MOF) files (.mof extension). (Citation: Dell WMI Persistence) Examples of events that may be subscribed to are the wall clock time or the computer's uptime. (Citation: Kazanciyan 2014) Several threat groups have reportedly used this technique to maintain persistence. (Citation: Mandiant M-Trends 2015)
comment: This technique has been revoked by T1546.003
deprecated: true

Rundll32
type: Class
subclass of: Defense Evasion Technique
subclass of: Execution Technique
attack-id: T1085
definition: The rundll32.exe program can be called to execute an arbitrary binary. Adversaries may take advantage of this functionality to proxy execution of code to avoid triggering security tools that may not monitor execution of the rundll32.exe process because of whitelists or false positives from Windows using rundll32.exe for normal operations.
comment: This technique has been revoked by T1218.011
deprecated: true

PowerShell
type: Class
subclass of: Execution Technique
attack-id: T1086
definition: PowerShell is a powerful interactive command-line interface and scripting environment included in the Windows operating system. (Citation: TechNet PowerShell) Adversaries can use PowerShell to perform a number of actions, including discovery of information and execution of code. Examples include the Start-Process cmdlet which can be used to run an executable and the Invoke-Command cmdlet which runs a command locally or on a remote computer.
comment: This technique has been revoked by T1059.001
deprecated: true

Account Discovery
type: Class
subclass of: Discovery Technique
attack-id: T1087
definition: Adversaries may attempt to get a listing of valid accounts, usernames, or email addresses on a system or within a compromised environment. This information can help adversaries determine which accounts exist, which can aid in follow-on behavior such as brute-forcing, spear-phishing attacks, or account takeovers (e.g., [Valid Accounts](https://attack.mitre.org/techniques/T1078)).

Local Account
type: Class
subclass of: Account Discovery
subclass of: Restriction
  on property: enumerates
  some values from: Local User Account
type: NamedIndividual
enumerates: Local User Account
attack-id: T1087.001
definition: Adversaries may attempt to get a listing of local system accounts. This information can help adversaries determine which local accounts exist on a system to aid in follow-on behavior.

Domain Account
type: Class
subclass of: Account Discovery
subclass of: Restriction
  on property: enumerates
  some values from: Domain User Account
type: NamedIndividual
enumerates: Domain User Account
attack-id: T1087.002
definition: Adversaries may attempt to get a listing of domain accounts. This information can help adversaries determine which domain accounts exist to aid in follow-on behavior such as targeting specific accounts which possess particular privileges.

Email Account
type: Class
subclass of: Account Discovery
attack-id: T1087.003
definition: Adversaries may attempt to get a listing of email addresses and accounts. Adversaries may try to dump Exchange address lists such as global address lists (GALs).(Citation: Microsoft Exchange Address Lists)

Cloud Account
type: Class
subclass of: Account Discovery
subclass of: Restriction
  on property: enumerates
  some values from: Cloud User Account
type: NamedIndividual
enumerates: Cloud User Account
attack-id: T1087.004
definition: Adversaries may attempt to get a listing of cloud accounts. Cloud accounts are those created and configured by an organization for use by users, remote support, services, or for administration of resources within a cloud service provider or SaaS application.

Bypass User Account Control
type: Class
subclass of: Defense Evasion Technique
subclass of: Privilege Escalation Technique
attack-id: T1088
definition: Windows User Account Control (UAC) allows a program to elevate its privileges to perform a task under administrator-level permissions by prompting the user for confirmation. The impact to the user ranges from denying the operation under high enforcement to allowing the user to perform the action if they are in the local administrators group and click through the prompt or allowing them to enter an administrator password to complete the action. (Citation: TechNet How UAC Works)
comment: This technique has been revoked by T1548.002
deprecated: true

Disabling Security Tools
type: Class
subclass of: Defense Evasion Technique
attack-id: T1089
definition: Adversaries may disable security tools to avoid possible detection of their tools and activities. This can take the form of killing security software or event logging processes, deleting Registry keys so that tools do not start at run time, or other methods to interfere with security scanning or event reporting.
comment: This technique has been revoked by T1562.001
deprecated: true

Proxy
type: Class
subclass of: Command and Control Technique
attack-id: T1090
definition: Adversaries may use a connection proxy to direct network traffic between systems or act as an intermediary for network communications to a command and control server to avoid direct connections to their infrastructure. Many tools exist that enable traffic redirection through proxies or port redirection, including [HTRAN](https://attack.mitre.org/software/S0040), ZXProxy, and ZXPortMap. (Citation: Trend Micro APT Attack Tools) Adversaries use these types of proxies to manage command and control communications, reduce the number of simultaneous outbound network connections, provide resiliency in the face of connection loss, or to ride over existing trusted communications paths between victims to avoid suspicion. Adversaries may chain together multiple proxies to further disguise the source of malicious traffic.

Internal Proxy
type: Class
subclass of: Proxy
subclass of: Restriction
  on property: produces
  some values from: Intranet Network Traffic
type: NamedIndividual
produces: Intranet Network Traffic
attack-id: T1090.001
definition: Adversaries may use an internal proxy to direct command and control traffic between two or more systems in a compromised environment. Many tools exist that enable traffic redirection through proxies or port redirection, including [HTRAN](https://attack.mitre.org/software/S0040), ZXProxy, and ZXPortMap. (Citation: Trend Micro APT Attack Tools) Adversaries use internal proxies to manage command and control communications inside a compromised environment, to reduce the number of simultaneous outbound network connections, to provide resiliency in the face of connection loss, or to ride over existing trusted communications paths between infected systems to avoid suspicion. Internal proxy connections may use common peer-to-peer (p2p) networking protocols, such as SMB, to better blend in with the environment.

External Proxy
type: Class
subclass of: Proxy
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Network Traffic
type: NamedIndividual
produces: Outbound Internet Network Traffic
attack-id: T1090.002
definition: Adversaries may use an external proxy to act as an intermediary for network communications to a command and control server to avoid direct connections to their infrastructure. Many tools exist that enable traffic redirection through proxies or port redirection, including [HTRAN](https://attack.mitre.org/software/S0040), ZXProxy, and ZXPortMap. (Citation: Trend Micro APT Attack Tools) Adversaries use these types of proxies to manage command and control communications, to provide resiliency in the face of connection loss, or to ride over existing trusted communications paths to avoid suspicion.

Multi-hop Proxy
type: Class
subclass of: Proxy
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Network Traffic
type: NamedIndividual
produces: Outbound Internet Network Traffic
attack-id: T1090.003
definition: Adversaries may chain together multiple proxies to disguise the source of malicious traffic. Typically, a defender will be able to identify the last proxy traffic traversed before it enters their network; the defender may or may not be able to identify any previous proxies before the last-hop proxy. This technique makes identifying the original source of the malicious traffic even more difficult by requiring the defender to trace malicious traffic through several proxies to identify its source.

Domain Fronting
type: Class
subclass of: Proxy
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Encrypted Web Traffic
type: NamedIndividual
produces: Outbound Internet Encrypted Web Traffic
attack-id: T1090.004
definition: Adversaries may take advantage of routing schemes in Content Delivery Networks (CDNs) and other services which host multiple domains to obfuscate the intended destination of HTTPS traffic or traffic tunneled through HTTPS. (Citation: Fifield Blocking Resistent Communication through domain fronting 2015) Domain fronting involves using different domain names in the SNI field of the TLS header and the Host field of the HTTP header. If both domains are served from the same CDN, then the CDN may route to the address specified in the HTTP header after unwrapping the TLS header. A variation of the the technique, "domainless" fronting, utilizes a SNI field that is left blank; this may allow the fronting to work even when the CDN attempts to validate that the SNI and HTTP Host fields match (if the blank SNI fields are ignored).

Replication Through Removable Media
type: Class
subclass of: Initial Access Technique
subclass of: Lateral Movement Technique
subclass of: Restriction
  on property: executes
  some values from: Removable Media Device
type: NamedIndividual
executes: Removable Media Device
attack-id: T1091
definition: Adversaries may move onto systems, possibly those on disconnected or air-gapped networks, by copying malware to removable media and taking advantage of Autorun features when the media is inserted into a system and executes. In the case of Lateral Movement, this may occur through modification of executable files stored on removable media or by copying malware and renaming it to look like a legitimate file to trick users into executing it on a separate system. In the case of Initial Access, this may occur through manual manipulation of the media, modification of systems used to initially format the media, or modification to the media's firmware itself.

Communication Through Removable Media
type: Class
subclass of: Command and Control Technique
subclass of: Restriction
  on property: modifies
  some values from: Removable Media Device
type: NamedIndividual
modifies: Removable Media Device
attack-id: T1092
definition: Adversaries can perform command and control between compromised hosts on potentially disconnected networks using removable media to transfer commands from system to system.(Citation: ESET Sednit USBStealer 2014) Both systems would need to be compromised, with the likelihood that an Internet-connected system was compromised first and the second through lateral movement by [Replication Through Removable Media](https://attack.mitre.org/techniques/T1091). Commands and files would be relayed from the disconnected system to the Internet-connected system to which the adversary has direct access.

Process Hollowing
type: Class
subclass of: Defense Evasion Technique
attack-id: T1093
definition: Process hollowing occurs when a process is created in a suspended state then its memory is unmapped and replaced with malicious code. Similar to [Process Injection](https://attack.mitre.org/techniques/T1055), execution of the malicious code is masked under a legitimate process and may evade defenses and detection analysis. (Citation: Leitch Hollowing) (Citation: Elastic Process Injection July 2017)
comment: This technique has been revoked by T1055.012
deprecated: true

Custom Command and Control Protocol
type: Class
subclass of: Command and Control Technique
attack-id: T1094
definition: Adversaries may communicate using a custom command and control protocol instead of encapsulating commands/data in an existing [Application Layer Protocol](https://attack.mitre.org/techniques/T1071). Implementations include mimicking well-known protocols or developing custom protocols (including raw sockets) on top of fundamental protocols provided by TCP/IP/another standard network stack.
comment: This technique has been revoked by T1095
deprecated: true

Non-Application Layer Protocol
type: Class
subclass of: Command and Control Technique
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Network Traffic
type: NamedIndividual
produces: Outbound Internet Network Traffic
attack-id: T1095
definition: Adversaries may use an OSI non-application layer protocol for communication between host and C2 server or among infected hosts within a network. The list of possible protocols is extensive.(Citation: Wikipedia OSI) Specific examples include use of network layer protocols, such as the Internet Control Message Protocol (ICMP), transport layer protocols, such as the User Datagram Protocol (UDP), session layer protocols, such as Socket Secure (SOCKS), as well as redirected/tunneled protocols, such as Serial over LAN (SOL).

NTFS File Attributes
type: Class
subclass of: Defense Evasion Technique
attack-id: T1096
definition: Every New Technology File System (NTFS) formatted partition contains a Master File Table (MFT) that maintains a record for every file/directory on the partition. (Citation: SpectorOps Host-Based Jul 2017) Within MFT entries are file attributes, (Citation: Microsoft NTFS File Attributes Aug 2010) such as Extended Attributes (EA) and Data [known as Alternate Data Streams (ADSs) when more than one Data attribute is present], that can be used to store arbitrary data (and even complete files). (Citation: SpectorOps Host-Based Jul 2017) (Citation: Microsoft File Streams) (Citation: MalwareBytes ADS July 2015) (Citation: Microsoft ADS Mar 2014)
comment: This technique has been revoked by T1564.004
deprecated: true

Pass the Ticket
type: Class
subclass of: Lateral Movement Technique
attack-id: T1097
definition: Pass the ticket (PtT) is a method of authenticating to a system using Kerberos tickets without having access to an account's password. Kerberos authentication can be used as the first step to lateral movement to a remote system.
comment: This technique has been revoked by T1550.003
deprecated: true

Account Manipulation
type: Class
subclass of: Persistence Technique
subclass of: Restriction
  on property: modifies
  some values from: User Account
type: NamedIndividual
modifies: User Account
attack-id: T1098
definition: Adversaries may manipulate accounts to maintain and/or elevate access to victim systems. Account manipulation may consist of any action that preserves or modifies adversary access to a compromised account, such as modifying credentials or permission groups.(Citation: FireEye SMOKEDHAM June 2021) These actions could also include account activity designed to subvert security policies, such as performing iterative password updates to bypass password duration policies and preserve the life of compromised credentials.

Additional Cloud Credentials
type: Class
subclass of: Account Manipulation
subclass of: Restriction
  on property: creates
  some values from: Credential
subclass of: Restriction
  on property: produces
  some values from: Intranet Administrative Network Traffic
type: NamedIndividual
creates: Credential
produces: Intranet Administrative Network Traffic
attack-id: T1098.001
definition: Adversaries may add adversary-controlled credentials to a cloud account to maintain persistent access to victim accounts and instances within the environment.

Additional Email Delegate Permissions
type: Class
subclass of: Account Manipulation
subclass of: Restriction
  on property: modifies
  some values from: Domain User Account
type: NamedIndividual
modifies: Domain User Account
attack-id: T1098.002
definition: Adversaries may grant additional permission levels to maintain persistent access to an adversary-controlled email account.

Additional Cloud Roles
type: Class
subclass of: Account Manipulation
subclass of: Restriction
  on property: modifies
  some values from: Global User Account
type: NamedIndividual
modifies: Global User Account
attack-id: T1098.003
definition: An adversary may add additional roles or permissions to an adversary-controlled cloud account to maintain persistent access to a tenant. For example, adversaries may update IAM policies in cloud-based environments or add a new global administrator in Office 365 environments.(Citation: AWS IAM Policies and Permissions)(Citation: Google Cloud IAM Policies)(Citation: Microsoft Support O365 Add Another Admin, October 2019)(Citation: Microsoft O365 Admin Roles) With sufficient permissions, a compromised account can gain almost unlimited access to data and settings (including the ability to reset the passwords of other admins).(Citation: Expel AWS Attacker)

SSH Authorized Keys
type: Class
subclass of: Account Manipulation
attack-id: T1098.004
definition: Adversaries may modify the SSH authorized_keys file to maintain persistence on a victim host. Linux distributions and macOS commonly use key-based authentication to secure the authentication process of SSH sessions for remote management. The authorized_keys file in SSH specifies the SSH keys that can be used for logging into the user account for which the file is configured. This file is usually found in the user's home directory under <user-home>/.ssh/authorized_keys.(Citation: SSH Authorized Keys) Users may edit the system’s SSH config file to modify the directives PubkeyAuthentication and RSAAuthentication to the value “yes” to ensure public key and RSA authentication are enabled. The SSH config file is usually located under /etc/ssh/sshd_config.

Device Registration
type: Class
subclass of: Account Manipulation
attack-id: T1098.005
definition: Adversaries may register a device to an adversary-controlled account. Devices may be registered in a multifactor authentication (MFA) system, which handles authentication to the network, or in a device management system, which handles device access and compliance.

Additional Container Cluster Roles
type: Class
subclass of: Account Manipulation
attack-id: T1098.006
definition: An adversary may add additional roles or permissions to an adversary-controlled user or service account to maintain persistent access to a container orchestration system. For example, an adversary with sufficient permissions may create a RoleBinding or a ClusterRoleBinding to bind a Role or ClusterRole to a Kubernetes account.(Citation: Kubernetes RBAC)(Citation: Aquasec Kubernetes Attack 2023) Where attribute-based access control (ABAC) is in use, an adversary with sufficient permissions may modify a Kubernetes ABAC policy to give the target account additional permissions.(Citation: Kuberentes ABAC)

Additional Local or Domain Groups
type: Class
subclass of: Account Manipulation
attack-id: T1098.007
definition: An adversary may add additional local or domain groups to an adversary-controlled account to maintain persistent access to a system or domain.

Timestomp
type: Class
subclass of: Defense Evasion Technique
attack-id: T1099
definition: Adversaries may take actions to hide the deployment of new, or modification of existing files to obfuscate their activities. Timestomping is a technique that modifies the timestamps of a file (the modify, access, create, and change times), often to mimic files that are in the same folder. This is done, for example, on files that have been modified or created by the adversary so that they do not appear conspicuous to forensic investigators or file analysis tools. Timestomping may be used along with file name [Masquerading](https://attack.mitre.org/techniques/T1036) to hide malware and tools. (Citation: WindowsIR Anti-Forensic Techniques)
comment: This technique has been revoked by T1070.006
deprecated: true

Web Shell
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1100
definition: A Web shell is a Web script that is placed on an openly accessible Web server to allow an adversary to use the Web server as a gateway into a network. A Web shell may provide a set of functions to execute or a command-line interface on the system that hosts the Web server. In addition to a server-side script, a Web shell may have a client interface program that is used to talk to the Web server (see, for example, China Chopper Web shell client). (Citation: Lee 2013)
comment: This technique has been revoked by T1505.003
deprecated: true

Security Support Provider
type: Class
subclass of: Persistence Technique
attack-id: T1101
definition: Windows Security Support Provider (SSP) DLLs are loaded into the Local Security Authority (LSA) process at system start. Once loaded into the LSA, SSP DLLs have access to encrypted and plaintext passwords that are stored in Windows, such as any logged-on user's Domain password or smart card PINs. The SSP configuration is stored in two Registry keys: HKLM\SYSTEM\CurrentControlSet\Control\Lsa\Security Packages and HKLM\SYSTEM\CurrentControlSet\Control\Lsa\OSConfig\Security Packages. An adversary may modify these Registry keys to add new SSPs, which will be loaded the next time the system boots, or when the AddSecurityPackage Windows API function is called.
comment: This technique has been revoked by T1547.005
deprecated: true

Web Service
type: Class
subclass of: Command and Control Technique
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Web Traffic
type: NamedIndividual
produces: Outbound Internet Web Traffic
attack-id: T1102
definition: Adversaries may use an existing, legitimate external Web service as a means for relaying data to/from a compromised system. Popular websites and social media acting as a mechanism for C2 may give a significant amount of cover due to the likelihood that hosts within a network are already communicating with them prior to a compromise. Using common services, such as those offered by Google or Twitter, makes it easier for adversaries to hide in expected noise. Web service providers commonly use SSL/TLS encryption, giving adversaries an added level of protection.

Dead Drop Resolver
type: Class
subclass of: Web Service
attack-id: T1102.001
definition: Adversaries may use an existing, legitimate external Web service to host information that points to additional command and control (C2) infrastructure. Adversaries may post content, known as a dead drop resolver, on Web services with embedded (and often obfuscated/encoded) domains or IP addresses. Once infected, victims will reach out to and be redirected by these resolvers.

Bidirectional Communication
type: Class
subclass of: Web Service
attack-id: T1102.002
definition: Adversaries may use an existing, legitimate external Web service as a means for sending commands to and receiving output from a compromised system over the Web service channel. Compromised systems may leverage popular websites and social media to host command and control (C2) instructions. Those infected systems can then send the output from those commands back over that Web service channel. The return traffic may occur in a variety of ways, depending on the Web service being utilized. For example, the return traffic may take the form of the compromised system posting a comment on a forum, issuing a pull request to development project, updating a document hosted on a Web service, or by sending a Tweet.

One-Way Communication
type: Class
subclass of: Web Service
attack-id: T1102.003
definition: Adversaries may use an existing, legitimate external Web service as a means for sending commands to a compromised system without receiving return output over the Web service channel. Compromised systems may leverage popular websites and social media to host command and control (C2) instructions. Those infected systems may opt to send the output from those commands back over a different C2 channel, including to another distinct Web service. Alternatively, compromised systems may return no output at all in cases where adversaries want to send instructions to systems and do not want a response.

AppInit DLLs
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1103
definition: Dynamic-link libraries (DLLs) that are specified in the AppInit_DLLs value in the Registry keys HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Windows or HKEY_LOCAL_MACHINE\Software\Wow6432Node\Microsoft\Windows NT\CurrentVersion\Windows are loaded by user32.dll into every process that loads user32.dll. In practice this is nearly every program, since user32.dll is a very common library. (Citation: Elastic Process Injection July 2017) Similar to [Process Injection](https://attack.mitre.org/techniques/T1055), these values can be abused to obtain persistence and privilege escalation by causing a malicious DLL to be loaded and run in the context of separate processes on the computer. (Citation: AppInit Registry)
comment: This technique has been revoked by T1546.010
deprecated: true

Multi-Stage Channels
type: Class
subclass of: Command and Control Technique
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Network Traffic
type: NamedIndividual
produces: Outbound Internet Network Traffic
attack-id: T1104
definition: Adversaries may create multiple stages for command and control that are employed under different conditions or for certain functions. Use of multiple stages may obfuscate the command and control channel to make detection more difficult.

Ingress Tool Transfer
type: Class
subclass of: Command and Control Technique
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Network Traffic
type: NamedIndividual
produces: Outbound Internet Network Traffic
attack-id: T1105
definition: Session is initiated by the client, and may be a custom protocol which is why it is related to generic network traffic instead of file transfer network traffic.

Native API
type: Class
subclass of: Execution Technique
subclass of: Restriction
  on property: invokes
  some values from: System Call
type: NamedIndividual
invokes: System Call
attack-id: T1106
definition: Adversaries may interact with the native OS application programming interface (API) to execute behaviors. Native APIs provide a controlled means of calling low-level OS services within the kernel, such as those involving hardware/devices, memory, and processes.(Citation: NT API Windows)(Citation: Linux Kernel API) These native APIs are leveraged by the OS during system boot (when other system components are not yet initialized) as well as carrying out tasks and requests during routine operations.

File Deletion
type: Class
subclass of: Defense Evasion Technique
attack-id: T1107
definition: Adversaries may delete files left behind by the actions of their intrusion activity. Malware, tools, or other non-native files dropped or created on a system by an adversary may leave traces to indicate to what was done within a network and how. Removal of these files can occur during an intrusion, or as part of a post-intrusion process to minimize the adversary's footprint.
comment: This technique has been revoked by T1070.004
deprecated: true

Redundant Access
type: Class
subclass of: Defense Evasion Technique
subclass of: Persistence Technique
attack-id: T1108
definition: **This technique has been deprecated. Please use [Create Account](https://attack.mitre.org/techniques/T1136), [Web Shell](https://attack.mitre.org/techniques/T1505/003), and [External Remote Services](https://attack.mitre.org/techniques/T1133) where appropriate.**
comment: **This technique has been deprecated. Please use [Create Account](https://attack.mitre.org/techniques/T1136), [Web Shell](https://attack.mitre.org/techniques/T1505/003), and [External Remote Services](https://attack.mitre.org/techniques/T1133) where appropriate.**
deprecated: true

Component Firmware
type: Class
subclass of: Defense Evasion Technique
subclass of: Persistence Technique
attack-id: T1109
definition: Some adversaries may employ sophisticated means to compromise computer components and install malicious firmware that will execute adversary code outside of the operating system and main system firmware or BIOS. This technique may be similar to [System Firmware](https://attack.mitre.org/techniques/T1019) but conducted upon other system components that may not have the same capability or level of integrity checking. Malicious device firmware could provide both a persistent level of access to systems despite potential typical failures to maintain access and hard disk re-images, as well as a way to evade host software-based defenses and integrity checks.
comment: This technique has been revoked by T1542.002
deprecated: true

Brute Force
type: Class
subclass of: Credential Access Technique
attack-id: T1110
definition: Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained.(Citation: TrendMicro Pawn Storm Dec 2020) Without knowledge of the password for an account or set of accounts, an adversary may systematically guess the password using a repetitive or iterative mechanism.(Citation: Dragos Crashoverride 2018) Brute forcing passwords can take place via interaction with a service that will check the validity of those credentials or offline against previously acquired credential data, such as password hashes.

Password Guessing
type: Class
subclass of: Brute Force
subclass of: Restriction
  on property: accesses
  some values from: Password
subclass of: Restriction
  on property: modifies
  some values from: Authentication Log
subclass of: Restriction
  on property: produces
  some values from: Authentication
type: NamedIndividual
accesses: Password
modifies: Authentication Log
produces: Authentication
attack-id: T1110.001
definition: Adversaries with no prior knowledge of legitimate credentials within the system or environment may guess passwords to attempt access to accounts. Without knowledge of the password for an account, an adversary may opt to systematically guess the password using a repetitive or iterative mechanism. An adversary may guess login credentials without prior knowledge of system or environment passwords during an operation by using a list of common passwords. Password guessing may or may not take into account the target's policies on password complexity or use policies that may lock accounts out after a number of failed attempts.

Password Cracking
type: Class
subclass of: Brute Force
subclass of: Restriction
  on property: accesses
  some values from: Password
type: NamedIndividual
accesses: Password
attack-id: T1110.002
definition: Adversaries may use password cracking to attempt to recover usable credentials, such as plaintext passwords, when credential material such as password hashes are obtained. [OS Credential Dumping](https://attack.mitre.org/techniques/T1003) can be used to obtain password hashes, this may only get an adversary so far when [Pass the Hash](https://attack.mitre.org/techniques/T1550/002) is not an option. Further, adversaries may leverage [Data from Configuration Repository](https://attack.mitre.org/techniques/T1602) in order to obtain hashed credentials for network devices.(Citation: US-CERT-TA18-106A)

Password Spraying
type: Class
subclass of: Brute Force
subclass of: Restriction
  on property: accesses
  some values from: Password
subclass of: Restriction
  on property: may-create
  some values from: Intranet Administrative Network Traffic
subclass of: Restriction
  on property: modifies
  some values from: Authentication Log
subclass of: Restriction
  on property: produces
  some values from: Authentication
type: NamedIndividual
accesses: Password
may-create: Intranet Administrative Network Traffic
modifies: Authentication Log
produces: Authentication
attack-id: T1110.003
definition: Adversaries may use a single or small list of commonly used passwords against many different accounts to attempt to acquire valid account credentials. Password spraying uses one password (e.g. 'Password01'), or a small list of commonly used passwords, that may match the complexity policy of the domain. Logins are attempted with that password against many different accounts on a network to avoid account lockouts that would normally occur when brute forcing a single account with many passwords. (Citation: BlackHillsInfosec Password Spraying)

Credential Stuffing
type: Class
subclass of: Brute Force
subclass of: Restriction
  on property: may-create
  some values from: Intranet Administrative Network Traffic
subclass of: Restriction
  on property: modifies
  some values from: Authentication Log
subclass of: Restriction
  on property: produces
  some values from: Authentication
type: NamedIndividual
may-create: Intranet Administrative Network Traffic
modifies: Authentication Log
produces: Authentication
attack-id: T1110.004
definition: Adversaries may use credentials obtained from breach dumps of unrelated accounts to gain access to target accounts through credential overlap. Occasionally, large numbers of username and password pairs are dumped online when a website or service is compromised and the user account credentials accessed. The information may be useful to an adversary attempting to compromise accounts by taking advantage of the tendency for users to use the same passwords across personal and business accounts.

Multi-Factor Authentication Interception
type: Class
subclass of: Credential Access Technique
subclass of: Restriction
  on property: may-access
  some values from: Security Token
type: NamedIndividual
may-access: Security Token
attack-id: T1111
definition: Adversaries may target multi-factor authentication (MFA) mechanisms, (i.e., smart cards, token generators, etc.) to gain access to credentials that can be used to access systems, services, and network resources. Use of MFA is recommended and provides a higher level of security than usernames and passwords alone, but organizations should be aware of techniques that could be used to intercept and bypass these security mechanisms.

Modify Registry
type: Class
subclass of: Defense Evasion Technique
subclass of: Restriction
  on property: modifies
  some values from: Windows Registry
type: NamedIndividual
modifies: Windows Registry
attack-id: T1112
definition: Adversaries may interact with the Windows Registry to hide configuration information within Registry keys, remove information as part of cleaning up, or as part of other techniques to aid in persistence and execution.

Screen Capture
type: Class
subclass of: Collection Technique
subclass of: Restriction
  on property: may-access
  some values from: Display Server
subclass of: Restriction
  on property: may-invoke
  some values from: Get Screen Capture
type: NamedIndividual
may-access: Display Server
may-invoke: Get Screen Capture
attack-id: T1113
definition: Adversaries may attempt to take screen captures of the desktop to gather information over the course of an operation. Screen capturing functionality may be included as a feature of a remote access tool used in post-compromise operations. Taking a screenshot is also typically possible through native utilities or API calls, such as CopyFromScreen, xwd, or screencapture.(Citation: CopyFromScreen .NET)(Citation: Antiquated Mac Malware)

Email Collection
type: Class
subclass of: Collection Technique
subclass of: Restriction
  on property: accesses
  some values from: Resource
type: NamedIndividual
accesses: Resource
attack-id: T1114
definition: Adversaries may target user email to collect sensitive information. Emails may contain sensitive data, including trade secrets or personal information, that can prove valuable to adversaries. Adversaries can collect or forward email from mail servers or clients.

Local Email Collection
type: Class
subclass of: Email Collection
subclass of: Restriction
  on property: reads
  some values from: Email
type: NamedIndividual
reads: Email
attack-id: T1114.001
definition: Adversaries may target user email on local systems to collect sensitive information. Files containing email data can be acquired from a user’s local system, such as Outlook storage or cache files.

Remote Email Collection
type: Class
subclass of: Email Collection
subclass of: Restriction
  on property: accesses
  some values from: Mail Server
type: NamedIndividual
accesses: Mail Server
attack-id: T1114.002
definition: Adversaries may target an Exchange server, Office 365, or Google Workspace to collect sensitive information. Adversaries may leverage a user's credentials and interact directly with the Exchange server to acquire information from within a network. Adversaries may also access externally facing Exchange services, Office 365, or Google Workspace to access email using credentials or access tokens. Tools such as [MailSniper](https://attack.mitre.org/software/S0413) can be used to automate searches for specific keywords.

Email Forwarding Rule
type: Class
subclass of: Email Collection
subclass of: Restriction
  on property: modifies
  some values from: Application Configuration
type: NamedIndividual
modifies: Application Configuration
attack-id: T1114.003
definition: Adversaries may setup email forwarding rules to collect sensitive information. Adversaries may abuse email forwarding rules to monitor the activities of a victim, steal information, and further gain intelligence on the victim or the victim’s organization to use as part of further exploits or operations.(Citation: US-CERT TA18-068A 2018) Furthermore, email forwarding rules can allow adversaries to maintain persistent access to victim's emails even after compromised credentials are reset by administrators.(Citation: Pfammatter - Hidden Inbox Rules) Most email clients allow users to create inbox rules for various email functions, including forwarding to a different recipient. These rules may be created through a local email application, a web interface, or by command-line interface. Messages can be forwarded to internal or external recipients, and there are no restrictions limiting the extent of this rule. Administrators may also create forwarding rules for user accounts with the same considerations and outcomes.(Citation: Microsoft Tim McMichael Exchange Mail Forwarding 2)(Citation: Mac Forwarding Rules)

Clipboard Data
type: Class
subclass of: Collection Technique
subclass of: Restriction
  on property: reads
  some values from: Clipboard
type: NamedIndividual
reads: Clipboard
attack-id: T1115
definition: Adversaries may collect data stored in the clipboard from users copying information within or between applications.

Code Signing
type: Class
subclass of: Defense Evasion Technique
attack-id: T1116
definition: Code signing provides a level of authenticity on a binary from the developer and a guarantee that the binary has not been tampered with. (Citation: Wikipedia Code Signing) However, adversaries are known to use code signing certificates to masquerade malware and tools as legitimate binaries (Citation: Janicab). The certificates used during an operation may be created, forged, or stolen by the adversary. (Citation: Securelist Digital Certificates) (Citation: Symantec Digital Certificates)
comment: This technique has been revoked by T1553.002
deprecated: true

Regsvr32
type: Class
subclass of: Defense Evasion Technique
subclass of: Execution Technique
attack-id: T1117
definition: Regsvr32.exe is a command-line program used to register and unregister object linking and embedding controls, including dynamic link libraries (DLLs), on Windows systems. Regsvr32.exe can be used to execute arbitrary binaries. (Citation: Microsoft Regsvr32)
comment: This technique has been revoked by T1218.010
deprecated: true

InstallUtil
type: Class
subclass of: Defense Evasion Technique
subclass of: Execution Technique
attack-id: T1118
definition: InstallUtil is a command-line utility that allows for installation and uninstallation of resources by executing specific installer components specified in .NET binaries. (Citation: MSDN InstallUtil) InstallUtil is located in the .NET directories on a Windows system: C:\Windows\Microsoft.NET\Framework\v<version>\InstallUtil.exe and C:\Windows\Microsoft.NET\Framework64\v<version>\InstallUtil.exe. InstallUtil.exe is digitally signed by Microsoft.
comment: This technique has been revoked by T1218.004
deprecated: true

Automated Collection
type: Class
subclass of: Collection Technique
subclass of: Restriction
  on property: accesses
  some values from: File
type: NamedIndividual
accesses: File
attack-id: T1119
definition: Once established within a system or network, an adversary may use automated techniques for collecting internal data. Methods for performing this technique could include use of a [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059) to search for and copy information fitting set criteria such as file type, location, or name at specific time intervals.

Peripheral Device Discovery
type: Class
subclass of: Discovery Technique
attack-id: T1120
definition: Adversaries may attempt to gather information about attached peripheral devices and components connected to a computer system.(Citation: Peripheral Discovery Linux)(Citation: Peripheral Discovery macOS) Peripheral devices could include auxiliary resources that support a variety of functionalities such as keyboards, printers, cameras, smart card readers, or removable storage. The information may be used to enhance their awareness of the system and network environment or may be used for further actions.

Regsvcs/Regasm
type: Class
subclass of: Defense Evasion Technique
subclass of: Execution Technique
attack-id: T1121
definition: Regsvcs and Regasm are Windows command-line utilities that are used to register .NET Component Object Model (COM) assemblies. Both are digitally signed by Microsoft. (Citation: MSDN Regsvcs) (Citation: MSDN Regasm)
comment: This technique has been revoked by T1218.009
deprecated: true

Component Object Model Hijacking
type: Class
subclass of: Defense Evasion Technique
subclass of: Persistence Technique
attack-id: T1122
definition: The Component Object Model (COM) is a system within Windows to enable interaction between software components through the operating system. (Citation: Microsoft Component Object Model) Adversaries can use this system to insert malicious code that can be executed in place of legitimate software through hijacking the COM references and relationships as a means for persistence. Hijacking a COM object requires a change in the Windows Registry to replace a reference to a legitimate system component which may cause that component to not work when executed. When that system component is executed through normal system operation the adversary's code will be executed instead. (Citation: GDATA COM Hijacking) An adversary is likely to hijack objects that are used frequently enough to maintain a consistent level of persistence, but are unlikely to break noticeable functionality within the system as to avoid system instability that could lead to detection.
comment: This technique has been revoked by T1546.015
deprecated: true

Audio Capture
type: Class
subclass of: Collection Technique
subclass of: Restriction
  on property: accesses
  some values from: Audio Input Device
type: NamedIndividual
accesses: Audio Input Device
attack-id: T1123
definition: An adversary can leverage a computer's peripheral devices (e.g., microphones and webcams) or applications (e.g., voice and video call services) to capture audio recordings for the purpose of listening into sensitive conversations to gather information.(Citation: ESET Attor Oct 2019)

System Time Discovery
type: Class
subclass of: Discovery Technique
subclass of: Restriction
  on property: may-invoke
  some values from: Create Process
subclass of: Restriction
  on property: may-invoke
  some values from: Get System Time
type: NamedIndividual
may-invoke: Create Process
may-invoke: Get System Time
attack-id: T1124
definition: An adversary may gather the system time and/or time zone settings from a local or remote system. The system time is set and stored by services, such as the Windows Time Service on Windows or systemsetup on macOS.(Citation: MSDN System Time)(Citation: Technet Windows Time Service)(Citation: systemsetup mac time) These time settings may also be synchronized between systems and services in an enterprise network, typically accomplished with a network time server within a domain.(Citation: Mac Time Sync)(Citation: linux system time)

Video Capture
type: Class
subclass of: Collection Technique
subclass of: Restriction
  on property: accesses
  some values from: Video Input Device
type: NamedIndividual
accesses: Video Input Device
attack-id: T1125
definition: An adversary can leverage a computer's peripheral devices (e.g., integrated cameras or webcams) or applications (e.g., video call services) to capture video recordings for the purpose of gathering information. Images may also be captured from devices or applications, potentially in specified intervals, in lieu of video files.

Network Share Connection Removal
type: Class
subclass of: Defense Evasion Technique
attack-id: T1126
definition: Adversaries may remove share connections that are no longer useful in order to clean up traces of their operation. Windows shared drive and [Windows Admin Shares](https://attack.mitre.org/techniques/T1077) connections can be removed when no longer needed. [Net](https://attack.mitre.org/software/S0039) is an example utility that can be used to remove network share connections with the net use \\system\share /delete command. (Citation: Technet Net Use)
comment: This technique has been revoked by T1070.005
deprecated: true

Trusted Developer Utilities Proxy Execution
type: Class
subclass of: Defense Evasion Technique
attack-id: T1127
definition: Adversaries may take advantage of trusted developer utilities to proxy execution of malicious payloads. There are many utilities used for software development related tasks that can be used to execute code in various forms to assist in development, debugging, and reverse engineering.(Citation: engima0x3 DNX Bypass)(Citation: engima0x3 RCSI Bypass)(Citation: Exploit Monday WinDbg)(Citation: LOLBAS Tracker) These utilities may often be signed with legitimate certificates that allow them to execute on a system and proxy execution of malicious code through a trusted process that effectively bypasses application control solutions.

MSBuild
type: Class
subclass of: Trusted Developer Utilities Proxy Execution
subclass of: Restriction
  on property: modifies
  some values from: Compiler Configuration File
subclass of: Restriction
  on property: runs
  some values from: Compiler
type: NamedIndividual
modifies: Compiler Configuration File
runs: Compiler
attack-id: T1127.001
definition: Adversaries may use MSBuild to proxy execution of code through a trusted Windows utility. MSBuild.exe (Microsoft Build Engine) is a software build platform used by Visual Studio. It handles XML formatted project files that define requirements for loading and building various platforms and configurations.(Citation: MSDN MSBuild)

ClickOnce
type: Class
subclass of: Trusted Developer Utilities Proxy Execution
attack-id: T1127.002
definition: Adversaries may use ClickOnce applications (.appref-ms and .application files) to proxy execution of code through a trusted Windows utility.(Citation: Burke/CISA ClickOnce BlackHat) ClickOnce is a deployment that enables a user to create self-updating Windows-based .NET applications (i.e, .XBAP, .EXE, or .DLL) that install and run from a file share or web page with minimal user interaction. The application launches as a child process of DFSVC.EXE, which is responsible for installing, launching, and updating the application.(Citation: SpectorOps Medium ClickOnce)

Netsh Helper DLL
type: Class
subclass of: Persistence Technique
attack-id: T1128
definition: Netsh.exe (also referred to as Netshell) is a command-line scripting utility used to interact with the network configuration of a system. It contains functionality to add helper DLLs for extending functionality of the utility. (Citation: TechNet Netsh) The paths to registered netsh.exe helper DLLs are entered into the Windows Registry at HKLM\SOFTWARE\Microsoft\Netsh.
comment: This technique has been revoked by T1546.007
deprecated: true

Shared Modules
type: Class
subclass of: Execution Technique
attack-id: T1129
definition: Adversaries may execute malicious payloads via loading shared modules. Shared modules are executable files that are loaded into processes to provide access to reusable code, such as specific custom functions or invoking OS API functions (i.e., [Native API](https://attack.mitre.org/techniques/T1106)).

Install Root Certificate
type: Class
subclass of: Defense Evasion Technique
attack-id: T1130
definition: Root certificates are used in public key cryptography to identify a root certificate authority (CA). When a root certificate is installed, the system or application will trust certificates in the root's chain of trust that have been signed by the root certificate. (Citation: Wikipedia Root Certificate) Certificates are commonly used for establishing secure TLS/SSL communications within a web browser. When a user attempts to browse a website that presents a certificate that is not trusted an error message will be displayed to warn the user of the security risk. Depending on the security settings, the browser may not allow the user to establish a connection to the website.
comment: This technique has been revoked by T1553.004
deprecated: true

Authentication Package
type: Class
subclass of: Persistence Technique
attack-id: T1131
definition: Windows Authentication Package DLLs are loaded by the Local Security Authority (LSA) process at system start. They provide support for multiple logon processes and multiple security protocols to the operating system. (Citation: MSDN Authentication Packages)
comment: This technique has been revoked by T1547.002
deprecated: true

Data Encoding
type: Class
subclass of: Command and Control Technique
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Network Traffic
type: NamedIndividual
produces: Outbound Internet Network Traffic
attack-id: T1132
definition: Adversaries may encode data to make the content of command and control traffic more difficult to detect. Command and control (C2) information can be encoded using a standard data encoding system. Use of data encoding may adhere to existing protocol specifications and includes use of ASCII, Unicode, Base64, MIME, or other binary-to-text and character encoding systems.(Citation: Wikipedia Binary-to-text Encoding) (Citation: Wikipedia Character Encoding) Some data encoding systems may also result in data compression, such as gzip.

Standard Encoding
type: Class
subclass of: Data Encoding
attack-id: T1132.001
definition: Adversaries may encode data with a standard data encoding system to make the content of command and control traffic more difficult to detect. Command and control (C2) information can be encoded using a standard data encoding system that adheres to existing protocol specifications. Common data encoding schemes include ASCII, Unicode, hexadecimal, Base64, and MIME.(Citation: Wikipedia Binary-to-text Encoding)(Citation: Wikipedia Character Encoding) Some data encoding systems may also result in data compression, such as gzip.

Non-Standard Encoding
type: Class
subclass of: Data Encoding
attack-id: T1132.002
definition: Adversaries may encode data with a non-standard data encoding system to make the content of command and control traffic more difficult to detect. Command and control (C2) information can be encoded using a non-standard data encoding system that diverges from existing protocol specifications. Non-standard data encoding schemes may be based on or related to standard data encoding schemes, such as a modified Base64 encoding for the message body of an HTTP request.(Citation: Wikipedia Binary-to-text Encoding) (Citation: Wikipedia Character Encoding)

External Remote Services
type: Class
subclass of: Initial Access Technique
subclass of: Persistence Technique
subclass of: Restriction
  on property: produces
  some values from: Authentication
subclass of: Restriction
  on property: produces
  some values from: Authorization
subclass of: Restriction
  on property: produces
  some values from: Network Session
type: NamedIndividual
produces: Authentication
produces: Authorization
produces: Network Session
attack-id: T1133
definition: Adversaries may leverage external-facing remote services to initially access and/or persist within a network. Remote services such as VPNs, Citrix, and other access mechanisms allow users to connect to internal enterprise network resources from external locations. There are often remote service gateways that manage connections and credential authentication for these services. Services such as [Windows Remote Management](https://attack.mitre.org/techniques/T1021/006) and [VNC](https://attack.mitre.org/techniques/T1021/005) can also be used externally.(Citation: MacOS VNC software for Remote Desktop)

Access Token Manipulation
type: Class
subclass of: Defense Evasion Technique
subclass of: Privilege Escalation Technique
attack-id: T1134
definition: Adversaries may modify access tokens to operate under a different user or system security context to perform actions and bypass access controls. Windows uses access tokens to determine the ownership of a running process. A user can manipulate access tokens to make a running process appear as though it is the child of a different process or belongs to someone other than the user that started the process. When this occurs, the process also takes on the security context associated with the new token.

Token Impersonation/Theft
type: Class
subclass of: Access Token Manipulation
subclass of: Restriction
  on property: copies
  some values from: Access Token
type: NamedIndividual
copies: Access Token
attack-id: T1134.001
definition: Adversaries may duplicate then impersonate another user's existing token to escalate privileges and bypass access controls. For example, an adversary can duplicate an existing token using `DuplicateToken` or `DuplicateTokenEx`.(Citation: DuplicateToken function) The token can then be used with `ImpersonateLoggedOnUser` to allow the calling thread to impersonate a logged on user's security context, or with `SetThreadToken` to assign the impersonated token to a thread.

Create Process with Token
type: Class
subclass of: Access Token Manipulation
subclass of: Restriction
  on property: copies
  some values from: Access Token
subclass of: Restriction
  on property: may-modify
  some values from: Event Log
type: NamedIndividual
copies: Access Token
may-modify: Event Log
attack-id: T1134.002
definition: Adversaries may create a new process with an existing token to escalate privileges and bypass access controls. Processes can be created with the token and resulting security context of another user using features such as CreateProcessWithTokenW and runas.(Citation: Microsoft RunAs)

Make and Impersonate Token
type: Class
subclass of: Access Token Manipulation
subclass of: Restriction
  on property: copies
  some values from: Access Token
subclass of: Restriction
  on property: creates
  some values from: Login Session
subclass of: Restriction
  on property: may-modify
  some values from: Event Log
type: NamedIndividual
copies: Access Token
creates: Login Session
may-modify: Event Log
attack-id: T1134.003
definition: Adversaries may make new tokens and impersonate users to escalate privileges and bypass access controls. For example, if an adversary has a username and password but the user is not logged onto the system the adversary can then create a logon session for the user using the `LogonUser` function.(Citation: LogonUserW function) The function will return a copy of the new session's access token and the adversary can use `SetThreadToken` to assign the token to a thread.

Parent PID Spoofing
type: Class
subclass of: Access Token Manipulation
subclass of: Restriction
  on property: invokes
  some values from: Create Process
type: NamedIndividual
invokes: Create Process
attack-id: T1134.004
definition: Adversaries may spoof the parent process identifier (PPID) of a new process to evade process-monitoring defenses or to elevate privileges. New processes are typically spawned directly from their parent, or calling, process unless explicitly specified. One way of explicitly assigning the PPID of a new process is via the CreateProcess API call, which supports a parameter that defines the PPID to use.(Citation: DidierStevens SelectMyParent Nov 2009) This functionality is used by Windows features such as User Account Control (UAC) to correctly set the PPID after a requested elevated process is spawned by SYSTEM (typically via svchost.exe or consent.exe) rather than the current user context.(Citation: Microsoft UAC Nov 2018)

SID-History Injection
type: Class
subclass of: Access Token Manipulation
subclass of: Restriction
  on property: modifies
  some values from: Access Control Configuration
type: NamedIndividual
modifies: Access Control Configuration
attack-id: T1134.005
definition: Adversaries may use SID-History Injection to escalate privileges and bypass access controls. The Windows security identifier (SID) is a unique value that identifies a user or group account. SIDs are used by Windows security in both security descriptors and access tokens. (Citation: Microsoft SID) An account can hold additional SIDs in the SID-History Active Directory attribute (Citation: Microsoft SID-History Attribute), allowing inter-operable account migration between domains (e.g., all values in SID-History are included in access tokens).

Network Share Discovery
type: Class
subclass of: Discovery Technique
attack-id: T1135
definition: Adversaries may look for folders and drives shared on remote systems as a means of identifying sources of information to gather as a precursor for Collection and to identify potential systems of interest for Lateral Movement. Networks often contain shared network drives and folders that enable users to access file directories on various systems across a network.

Create Account
type: Class
subclass of: Persistence Technique
subclass of: Restriction
  on property: creates
  some values from: User Account
type: NamedIndividual
creates: User Account
attack-id: T1136
definition: Adversaries may create an account to maintain access to victim systems.(Citation: Symantec WastedLocker June 2020) With a sufficient level of access, creating such accounts may be used to establish secondary credentialed access that do not require persistent remote access tools to be deployed on the system.

Local Account
type: Class
subclass of: Create Account
subclass of: Restriction
  on property: creates
  some values from: Local User Account
type: NamedIndividual
creates: Local User Account
attack-id: T1136.001
definition: Adversaries may create a local account to maintain access to victim systems. Local accounts are those configured by an organization for use by users, remote support, services, or for administration on a single system or service.

Domain Account
type: Class
subclass of: Create Account
subclass of: Restriction
  on property: creates
  some values from: Domain User Account
type: NamedIndividual
creates: Domain User Account
attack-id: T1136.002
definition: Adversaries may create a domain account to maintain access to victim systems. Domain accounts are those managed by Active Directory Domain Services where access and permissions are configured across systems and services that are part of that domain. Domain accounts can cover user, administrator, and service accounts. With a sufficient level of access, the net user /add /domain command can be used to create a domain account.(Citation: Savill 1999)

Cloud Account
type: Class
subclass of: Create Account
subclass of: Restriction
  on property: creates
  some values from: Cloud User Account
type: NamedIndividual
creates: Cloud User Account
attack-id: T1136.003
definition: Adversaries may create a cloud account to maintain access to victim systems. With a sufficient level of access, such accounts may be used to establish secondary credentialed access that does not require persistent remote access tools to be deployed on the system.(Citation: Microsoft O365 Admin Roles)(Citation: Microsoft Support O365 Add Another Admin, October 2019)(Citation: AWS Create IAM User)(Citation: GCP Create Cloud Identity Users)(Citation: Microsoft Azure AD Users)

Office Application Startup
type: Class
subclass of: Persistence Technique
attack-id: T1137
definition: Adversaries may leverage Microsoft Office-based applications for persistence between startups. Microsoft Office is a fairly common application suite on Windows-based operating systems within an enterprise network. There are multiple mechanisms that can be used with Office for persistence when an Office-based application is started; this can include the use of Office Template Macros and add-ins.

Office Template Macros
type: Class
subclass of: Office Application Startup
subclass of: Restriction
  on property: may-add
  some values from: Executable Script
subclass of: Restriction
  on property: may-modify
  some values from: Executable Script
subclass of: Restriction
  on property: may-modify
  some values from: System Configuration Database Record
type: NamedIndividual
may-add: Executable Script
may-modify: Executable Script
may-modify: System Configuration Database Record
attack-id: T1137.001
definition: Adversaries may abuse Microsoft Office templates to obtain persistence on a compromised system. Microsoft Office contains templates that are part of common Office applications and are used to customize styles. The base templates within the application are used each time an application starts. (Citation: Microsoft Change Normal Template)

Office Test
type: Class
subclass of: Office Application Startup
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database Record
type: NamedIndividual
modifies: System Configuration Database Record
attack-id: T1137.002
definition: Adversaries may abuse the Microsoft Office "Office Test" Registry key to obtain persistence on a compromised system. An Office Test Registry location exists that allows a user to specify an arbitrary DLL that will be executed every time an Office application is started. This Registry key is thought to be used by Microsoft to load DLLs for testing and debugging purposes while developing Office applications. This Registry key is not created by default during an Office installation.(Citation: Hexacorn Office Test)(Citation: Palo Alto Office Test Sofacy)

Outlook Forms
type: Class
subclass of: Office Application Startup
subclass of: Restriction
  on property: adds
  some values from: Office Application File
type: NamedIndividual
adds: Office Application File
attack-id: T1137.003
definition: Adversaries may abuse Microsoft Outlook forms to obtain persistence on a compromised system. Outlook forms are used as templates for presentation and functionality in Outlook messages. Custom Outlook forms can be created that will execute code when a specifically crafted email is sent by an adversary utilizing the same custom Outlook form.(Citation: SensePost Outlook Forms)

Outlook Home Page
type: Class
subclass of: Office Application Startup
subclass of: Restriction
  on property: modifies
  some values from: Application Configuration Database
type: NamedIndividual
modifies: Application Configuration Database
attack-id: T1137.004
definition: Adversaries may abuse Microsoft Outlook's Home Page feature to obtain persistence on a compromised system. Outlook Home Page is a legacy feature used to customize the presentation of Outlook folders. This feature allows for an internal or external URL to be loaded and presented whenever a folder is opened. A malicious HTML page can be crafted that will execute code when loaded by Outlook Home Page.(Citation: SensePost Outlook Home Page)

Outlook Rules
type: Class
subclass of: Office Application Startup
subclass of: Restriction
  on property: modifies
  some values from: Application Configuration Database
type: NamedIndividual
modifies: Application Configuration Database
attack-id: T1137.005
definition: Adversaries may abuse Microsoft Outlook rules to obtain persistence on a compromised system. Outlook rules allow a user to define automated behavior to manage email messages. A benign rule might, for example, automatically move an email to a particular folder in Outlook if it contains specific words from a specific sender. Malicious Outlook rules can be created that can trigger code execution when an adversary sends a specifically crafted email to that user.(Citation: SilentBreak Outlook Rules)

Add-ins
type: Class
subclass of: Office Application Startup
subclass of: Restriction
  on property: adds
  some values from: Software
subclass of: Restriction
  on property: may-modify
  some values from: System Configuration Database
subclass of: Restriction
  on property: modifies
  some values from: Office Application
type: NamedIndividual
adds: Software
may-modify: System Configuration Database
modifies: Office Application
attack-id: T1137.006
definition: Adversaries may abuse Microsoft Office add-ins to obtain persistence on a compromised system. Office add-ins can be used to add functionality to Office programs. (Citation: Microsoft Office Add-ins) There are different types of add-ins that can be used by the various Office products; including Word/Excel add-in Libraries (WLL/XLL), VBA add-ins, Office Component Object Model (COM) add-ins, automation add-ins, VBA Editor (VBE), Visual Studio Tools for Office (VSTO) add-ins, and Outlook add-ins. (Citation: MRWLabs Office Persistence Add-ins)(Citation: FireEye Mail CDS 2018)

Application Shimming
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1138
definition: The Microsoft Windows Application Compatibility Infrastructure/Framework (Application Shim) was created to allow for backward compatibility of software as the operating system codebase changes over time. For example, the application shimming feature allows developers to apply fixes to applications (without rewriting code) that were created for Windows XP so that it will work with Windows 10. (Citation: Elastic Process Injection July 2017) Within the framework, shims are created to act as a buffer between the program (or more specifically, the Import Address Table) and the Windows OS. When a program is executed, the shim cache is referenced to determine if the program requires the use of the shim database (.sdb). If so, the shim database uses [Hooking](https://attack.mitre.org/techniques/T1179) to redirect the code as necessary in order to communicate with the OS.
comment: This technique has been revoked by T1546.011
deprecated: true

Bash History
type: Class
subclass of: Credential Access Technique
attack-id: T1139
definition: Bash keeps track of the commands users type on the command-line with the "history" utility. Once a user logs out, the history is flushed to the user’s .bash_history file. For each user, this file resides at the same location: ~/.bash_history. Typically, this file keeps track of the user’s last 500 commands. Users often type usernames and passwords on the command-line as parameters to programs, which then get saved to this file when they log out. Attackers can abuse this by looking through the file for potential credentials. (Citation: External to DA, the OS X Way)
comment: This technique has been revoked by T1552.003
deprecated: true

Deobfuscate/Decode Files or Information
type: Class
subclass of: Defense Evasion Technique
subclass of: Restriction
  on property: invokes
  some values from: Create Process
subclass of: Restriction
  on property: may-add
  some values from: Executable File
subclass of: Restriction
  on property: may-modify
  some values from: Event Log
type: NamedIndividual
invokes: Create Process
may-add: Executable File
may-modify: Event Log
attack-id: T1140
definition: Adversaries may use [Obfuscated Files or Information](https://attack.mitre.org/techniques/T1027) to hide artifacts of an intrusion from analysis. They may require separate mechanisms to decode or deobfuscate that information depending on how they intend to use it. Methods for doing that include built-in functionality of malware or by using utilities present on the system.

Input Prompt
type: Class
subclass of: Credential Access Technique
attack-id: T1141
definition: When programs are executed that need additional privileges than are present in the current user context, it is common for the operating system to prompt the user for proper credentials to authorize the elevated privileges for the task (ex: [Bypass User Account Control](https://attack.mitre.org/techniques/T1088)).
comment: This technique has been revoked by T1056.002
deprecated: true

Keychain
type: Class
subclass of: Credential Access Technique
subclass of: Restriction
  on property: accesses
  some values from: Encrypted Credential
type: NamedIndividual
accesses: Encrypted Credential
attack-id: T1142
definition: Keychains are the built-in way for macOS to keep track of users' passwords and credentials for many services and features such as WiFi passwords, websites, secure notes, certificates, and Kerberos. Keychain files are located in ~/Library/Keychains/,/Library/Keychains/, and /Network/Library/Keychains/. (Citation: Wikipedia keychain) The security command-line utility, which is built into macOS by default, provides a useful way to manage these credentials.
comment: This technique has been revoked by T1555.001
deprecated: true

Hidden Window
type: Class
subclass of: Defense Evasion Technique
attack-id: T1143
definition: Adversaries may implement hidden windows to conceal malicious activity from the plain sight of users. In some cases, windows that would typically be displayed when an application carries out an operation can be hidden. This may be utilized by system administrators to avoid disrupting user work environments when carrying out administrative tasks. Adversaries may abuse operating system functionality to hide otherwise visible windows from users so as not to alert the user to adversary activity on the system.
comment: This technique has been revoked by T1564.003
deprecated: true

Gatekeeper Bypass
type: Class
subclass of: Defense Evasion Technique
attack-id: T1144
definition: In macOS and OS X, when applications or programs are downloaded from the internet, there is a special attribute set on the file called com.apple.quarantine. This attribute is read by Apple's Gatekeeper defense program at execution time and provides a prompt to the user to allow or deny execution.
comment: This technique has been revoked by T1553.001
deprecated: true

Private Keys
type: Class
subclass of: Credential Access Technique
attack-id: T1145
definition: Private cryptographic keys and certificates are used for authentication, encryption/decryption, and digital signatures. (Citation: Wikipedia Public Key Crypto)
comment: This technique has been revoked by T1552.004
deprecated: true

Clear Command History
type: Class
subclass of: Defense Evasion Technique
attack-id: T1146
definition: In addition to clearing system logs, an adversary may clear the command history of a compromised account to conceal the actions undertaken during an intrusion. macOS and Linux both keep track of the commands users type in their terminal so that users can retrace what they've done. These logs can be accessed in a few different ways. While logged in, this command history is tracked in a file pointed to by the environment variable HISTFILE. When a user logs off a system, this information is flushed to a file in the user's home directory called ~/.bash_history. The benefit of this is that it allows users to go back to commands they've used before in different sessions. Since everything typed on the command-line is saved, passwords passed in on the command line are also saved. Adversaries can abuse this by searching these files for cleartext passwords. Additionally, adversaries can use a variety of methods to prevent their own commands from appear in these logs such as unset HISTFILE, export HISTFILESIZE=0, history -c, rm ~/.bash_history.
comment: This technique has been revoked by T1070.003
deprecated: true

Hidden Users
type: Class
subclass of: Defense Evasion Technique
attack-id: T1147
definition: Every user account in macOS has a userID associated with it. When creating a user, you can specify the userID for that account. There is a property value in /Library/Preferences/com.apple.loginwindow called Hide500Users that prevents users with userIDs 500 and lower from appearing at the login screen. By using the [Create Account](https://attack.mitre.org/techniques/T1136) technique with a userID under 500 and enabling this property (setting it to Yes), an adversary can hide their user accounts much more easily: sudo dscl . -create /Users/username UniqueID 401 (Citation: Cybereason OSX Pirrit).
comment: This technique has been revoked by T1564.002
deprecated: true

HISTCONTROL
type: Class
subclass of: Defense Evasion Technique
attack-id: T1148
definition: The HISTCONTROL environment variable keeps track of what should be saved by the history command and eventually into the ~/.bash_history file when a user logs out. This setting can be configured to ignore commands that start with a space by simply setting it to "ignorespace". HISTCONTROL can also be set to ignore duplicate commands by setting it to "ignoredups". In some Linux systems, this is set by default to "ignoreboth" which covers both of the previous examples. This means that “ ls” will not be saved, but “ls” would be saved by history. HISTCONTROL does not exist by default on macOS, but can be set by the user and will be respected. Adversaries can use this to operate without leaving traces by simply prepending a space to all of their terminal commands.
comment: This technique has been revoked by T1562.003
deprecated: true

LC_MAIN Hijacking
type: Class
subclass of: Defense Evasion Technique
attack-id: T1149
definition: **This technique has been deprecated and should no longer be used.**
comment: **This technique has been deprecated and should no longer be used.**
deprecated: true

Plist Modification
type: Class
subclass of: Defense Evasion Technique
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1150
definition: Property list (plist) files contain all of the information that macOS and OS X uses to configure applications and services. These files are UTF-8 encoded and formatted like XML documents via a series of keys surrounded by < >. They detail when programs should execute, file paths to the executables, program arguments, required OS permissions, and many others. plists are located in certain locations depending on their purpose such as /Library/Preferences (which execute with elevated privileges) and ~/Library/Preferences (which execute with a user's privileges).
comment: This technique has been revoked by T1547.011
deprecated: true

Space after Filename
type: Class
subclass of: Defense Evasion Technique
subclass of: Execution Technique
attack-id: T1151
definition: Adversaries can hide a program's true filetype by changing the extension of a file. With certain file types (specifically this does not work with .app extensions), appending a space to the end of a filename will change how the file is processed by the operating system. For example, if there is a Mach-O executable file called evil.bin, when it is double clicked by a user, it will launch Terminal.app and execute. If this file is renamed to evil.txt, then when double clicked by a user, it will launch with the default text editing application (not executing the binary). However, if the file is renamed to "evil.txt " (note the space at the end), then when double clicked by a user, the true file type is determined by the OS and handled appropriately and the binary will be executed (Citation: Mac Backdoors are back).
comment: This technique has been revoked by T1036.006
deprecated: true

Launchctl
type: Class
subclass of: Defense Evasion Technique
subclass of: Execution Technique
subclass of: Persistence Technique
attack-id: T1152
definition: Launchctl controls the macOS launchd process which handles things like launch agents and launch daemons, but can execute other commands or programs itself. Launchctl supports taking subcommands on the command-line, interactively, or even redirected from standard input. By loading or reloading launch agents or launch daemons, adversaries can install persistence or execute changes they made (Citation: Sofacy Komplex Trojan). Running a command from launchctl is as simple as launchctl submit -l <labelName> -- /Path/to/thing/to/execute "arg" "arg" "arg". Loading, unloading, or reloading launch agents or launch daemons can require elevated privileges.
comment: This technique has been revoked by T1569.001
deprecated: true

Source
type: Class
subclass of: Execution Technique
attack-id: T1153
definition: **This technique has been deprecated and should no longer be used.**
comment: **This technique has been deprecated and should no longer be used.**
deprecated: true

Trap
type: Class
subclass of: Execution Technique
subclass of: Persistence Technique
attack-id: T1154
definition: The trap command allows programs and shells to specify commands that will be executed upon receiving interrupt signals. A common situation is a script allowing for graceful termination and handling of common keyboard interrupts like ctrl+c and ctrl+d. Adversaries can use this to register code to be executed when the shell encounters specific interrupts either to gain execution or as a persistence mechanism. Trap commands are of the following format trap 'command list' signals where "command list" will be executed when "signals" are received.(Citation: Trap Manual)(Citation: Cyberciti Trap Statements)
comment: This technique has been revoked by T1546.005
deprecated: true

AppleScript
type: Class
subclass of: Execution Technique
attack-id: T1155
definition: macOS and OS X applications send AppleEvent messages to each other for interprocess communications (IPC). These messages can be easily scripted with AppleScript for local or remote IPC. Osascript executes AppleScript and any other Open Scripting Architecture (OSA) language scripts. A list of OSA languages installed on a system can be found by using the osalang program.
comment: This technique has been revoked by T1059.002
deprecated: true

Malicious Shell Modification
type: Class
subclass of: Persistence Technique
attack-id: T1156
definition: Adversaries may establish persistence through executing malicious commands triggered by a user’s shell. User shells execute several configuration scripts at different points throughout the session based on events. For example, when a user opens a command line interface or remotely logs in (such as SSH) a login shell is initiated. The login shell executes scripts from the system (/etc) and the user’s home directory (~/) to configure the environment. All login shells on a system use /etc/profile when initiated. These configuration scripts run at the permission level of their directory and are often used to set environment variables, create aliases, and customize the user’s environment. When the shell exits or terminates, additional shell scripts are executed to ensure the shell exits appropriately.
comment: This technique has been revoked by T1546.004
deprecated: true

Dylib Hijacking
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1157
definition: macOS and OS X use a common method to look for required dynamic libraries (dylib) to load into a program based on search paths. Adversaries can take advantage of ambiguous paths to plant dylibs to gain privilege escalation or persistence.
comment: This technique has been revoked by T1574.004
deprecated: true

Hidden Files and Directories
type: Class
subclass of: Defense Evasion Technique
subclass of: Persistence Technique
attack-id: T1158
definition: To prevent normal users from accidentally changing special files on a system, most operating systems have the concept of a ‘hidden’ file. These files don’t show up when a user browses the file system with a GUI or when using normal commands on the command line. Users must explicitly ask to show the hidden files either via a series of Graphical User Interface (GUI) prompts or with command line switches (dir /a for Windows and ls –a for Linux and macOS).
comment: This technique has been revoked by T1564.001
deprecated: true

Launch Agent
type: Class
subclass of: Persistence Technique
attack-id: T1159
definition: Per Apple’s developer documentation, when a user logs in, a per-user launchd process is started which loads the parameters for each launch-on-demand user agent from the property list (plist) files found in /System/Library/LaunchAgents, /Library/LaunchAgents, and $HOME/Library/LaunchAgents (Citation: AppleDocs Launch Agent Daemons) (Citation: OSX Keydnap malware) (Citation: Antiquated Mac Malware). These launch agents have property list files which point to the executables that will be launched (Citation: OSX.Dok Malware).
comment: This technique has been revoked by T1543.001
deprecated: true

Launch Daemon
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1160
definition: Per Apple’s developer documentation, when macOS and OS X boot up, launchd is run to finish system initialization. This process loads the parameters for each launch-on-demand system-level daemon from the property list (plist) files found in /System/Library/LaunchDaemons and /Library/LaunchDaemons (Citation: AppleDocs Launch Agent Daemons). These LaunchDaemons have property list files which point to the executables that will be launched (Citation: Methods of Mac Malware Persistence).
comment: This technique has been revoked by T1543.004
deprecated: true

LC_LOAD_DYLIB Addition
type: Class
subclass of: Persistence Technique
attack-id: T1161
definition: Mach-O binaries have a series of headers that are used to perform certain operations when a binary is loaded. The LC_LOAD_DYLIB header in a Mach-O binary tells macOS and OS X which dynamic libraries (dylibs) to load during execution time. These can be added ad-hoc to the compiled binary as long adjustments are made to the rest of the fields and dependencies (Citation: Writing Bad Malware for OSX). There are tools available to perform these changes. Any changes will invalidate digital signatures on binaries because the binary is being modified. Adversaries can remediate this issue by simply removing the LC_CODE_SIGNATURE command from the binary so that the signature isn’t checked at load time (Citation: Malware Persistence on OS X).
comment: This technique has been revoked by T1546.006
deprecated: true

Login Item
type: Class
subclass of: Persistence Technique
attack-id: T1162
definition: MacOS provides the option to list specific applications to run when a user logs in. These applications run under the logged in user's context, and will be started every time the user logs in. Login items installed using the Service Management Framework are not visible in the System Preferences and can only be removed by the application that created them (Citation: Adding Login Items). Users have direct control over login items installed using a shared file list which are also visible in System Preferences (Citation: Adding Login Items). These login items are stored in the user's ~/Library/Preferences/ directory in a plist file called com.apple.loginitems.plist (Citation: Methods of Mac Malware Persistence). Some of these applications can open visible dialogs to the user, but they don’t all have to since there is an option to ‘Hide’ the window. If an adversary can register their own login item or modified an existing one, then they can use it to execute their code for a persistence mechanism each time the user logs in (Citation: Malware Persistence on OS X) (Citation: OSX.Dok Malware). The API method SMLoginItemSetEnabled can be used to set Login Items, but scripting languages like [AppleScript](https://attack.mitre.org/techniques/T1155) can do this as well (Citation: Adding Login Items).
comment: This technique has been revoked by T1547.011
deprecated: true

Rc.common
type: Class
subclass of: Persistence Technique
attack-id: T1163
definition: During the boot process, macOS executes source /etc/rc.common, which is a shell script containing various utility functions. This file also defines routines for processing command-line arguments and for gathering system settings, and is thus recommended to include in the start of Startup Item Scripts (Citation: Startup Items). In macOS and OS X, this is now a deprecated technique in favor of launch agents and launch daemons, but is currently still used.
comment: This technique has been revoked by T1037.004
deprecated: true

Re-opened Applications
type: Class
subclass of: Persistence Technique
attack-id: T1164
definition: Starting in Mac OS X 10.7 (Lion), users can specify certain applications to be re-opened when a user reboots their machine. While this is usually done via a Graphical User Interface (GUI) on an app-by-app basis, there are property list files (plist) that contain this information as well located at ~/Library/Preferences/com.apple.loginwindow.plist and ~/Library/Preferences/ByHost/com.apple.loginwindow.* .plist.
comment: This technique has been revoked by T1547.007
deprecated: true

Startup Items
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1165
definition: Per Apple’s documentation, startup items execute during the final phase of the boot process and contain shell scripts or other executable files along with configuration information used by the system to determine the execution order for all startup items (Citation: Startup Items). This is technically a deprecated version (superseded by Launch Daemons), and thus the appropriate folder, /Library/StartupItems isn’t guaranteed to exist on the system by default, but does appear to exist by default on macOS Sierra. A startup item is a directory whose executable and configuration property list (plist), StartupParameters.plist, reside in the top-level directory.
comment: This technique has been revoked by T1037.005
deprecated: true

Setuid and Setgid
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1166
definition: When the setuid or setgid bits are set on Linux or macOS for an application, this means that the application will run with the privileges of the owning user or group respectively (Citation: setuid man page). Normally an application is run in the current user’s context, regardless of which user or group owns the application. There are instances where programs need to be executed in an elevated context to function properly, but the user running them doesn’t need the elevated privileges. Instead of creating an entry in the sudoers file, which must be done by root, any user can specify the setuid or setgid flag to be set for their own applications. These bits are indicated with an "s" instead of an "x" when viewing a file's attributes via ls -l. The chmod program can set these bits with via bitmasking, chmod 4777 [file] or via shorthand naming, chmod u+s [file].
comment: This technique has been revoked by T1548.001
deprecated: true

Securityd Memory
type: Class
subclass of: Credential Access Technique
attack-id: T1167
definition: In OS X prior to El Capitan, users with root access can read plaintext keychain passwords of logged-in users because Apple’s keychain implementation allows these credentials to be cached so that users are not repeatedly prompted for passwords. (Citation: OS X Keychain) (Citation: External to DA, the OS X Way) Apple’s securityd utility takes the user’s logon password, encrypts it with PBKDF2, and stores this master key in memory. Apple also uses a set of keys and algorithms to encrypt the user’s password, but once the master key is found, an attacker need only iterate over the other values to unlock the final password. (Citation: OS X Keychain)
comment: This technique has been revoked by T1555.002
deprecated: true

Local Job Scheduling
type: Class
subclass of: Execution Technique
subclass of: Persistence Technique
attack-id: T1168
definition: On Linux and macOS systems, multiple methods are supported for creating pre-scheduled and periodic background jobs: cron, (Citation: Die.net Linux crontab Man Page) at, (Citation: Die.net Linux at Man Page) and launchd. (Citation: AppleDocs Scheduling Timed Jobs) Unlike [Scheduled Task/Job](https://attack.mitre.org/techniques/T1053) on Windows systems, job scheduling on Linux-based systems cannot be done remotely unless used in conjunction within an established remote session, like secure shell (SSH).
comment: This technique has been revoked by T1053
deprecated: true

Sudo
type: Class
subclass of: Privilege Escalation Technique
attack-id: T1169
definition: The sudoers file, /etc/sudoers, describes which users can run which commands and from which terminals. This also describes which commands users can run as other users or groups. This provides the idea of least privilege such that users are running in their lowest possible permissions for most of the time and only elevate to other users or permissions as needed, typically by prompting for a password. However, the sudoers file can also specify when to not prompt users for passwords with a line like user1 ALL=(ALL) NOPASSWD: ALL (Citation: OSX.Dok Malware).
comment: This technique has been revoked by T1548.003
deprecated: true

Mshta
type: Class
subclass of: Defense Evasion Technique
subclass of: Execution Technique
attack-id: T1170
definition: Mshta.exe is a utility that executes Microsoft HTML Applications (HTA). HTA files have the file extension .hta. (Citation: Wikipedia HTML Application) HTAs are standalone applications that execute using the same models and technologies of Internet Explorer, but outside of the browser. (Citation: MSDN HTML Applications)
comment: This technique has been revoked by T1218.005
deprecated: true

LLMNR/NBT-NS Poisoning and Relay
type: Class
subclass of: Credential Access Technique
attack-id: T1171
definition: Link-Local Multicast Name Resolution (LLMNR) and NetBIOS Name Service (NBT-NS) are Microsoft Windows components that serve as alternate methods of host identification. LLMNR is based upon the Domain Name System (DNS) format and allows hosts on the same local link to perform name resolution for other hosts. NBT-NS identifies systems on a local network by their NetBIOS name. (Citation: Wikipedia LLMNR) (Citation: TechNet NetBIOS)
comment: This technique has been revoked by T1557.001
deprecated: true

Domain Fronting
type: Class
subclass of: Command and Control Technique
attack-id: T1172
definition: Domain fronting takes advantage of routing schemes in Content Delivery Networks (CDNs) and other services which host multiple domains to obfuscate the intended destination of HTTPS traffic or traffic tunneled through HTTPS. (Citation: Fifield Blocking Resistent Communication through domain fronting 2015) The technique involves using different domain names in the SNI field of the TLS header and the Host field of the HTTP header. If both domains are served from the same CDN, then the CDN may route to the address specified in the HTTP header after unwrapping the TLS header. A variation of the the technique, "domainless" fronting, utilizes a SNI field that is left blank; this may allow the fronting to work even when the CDN attempts to validate that the SNI and HTTP Host fields match (if the blank SNI fields are ignored).
comment: This technique has been revoked by T1090.004
deprecated: true

Dynamic Data Exchange
type: Class
subclass of: Execution Technique
attack-id: T1173
definition: Windows Dynamic Data Exchange (DDE) is a client-server protocol for one-time and/or continuous inter-process communication (IPC) between applications. Once a link is established, applications can autonomously exchange transactions consisting of strings, warm data links (notifications when a data item changes), hot data links (duplications of changes to a data item), and requests for command execution.
comment: This technique has been revoked by T1559.002
deprecated: true

Password Filter DLL
type: Class
subclass of: Credential Access Technique
attack-id: T1174
definition: Windows password filters are password policy enforcement mechanisms for both domain and local accounts. Filters are implemented as dynamic link libraries (DLLs) containing a method to validate potential passwords against password policies. Filter DLLs can be positioned on local computers for local accounts and/or domain controllers for domain accounts.
comment: This technique has been revoked by T1556.002
deprecated: true

Component Object Model and Distributed COM
type: Class
subclass of: Execution Technique
subclass of: Lateral Movement Technique
attack-id: T1175
definition: **This technique has been deprecated. Please use [Distributed Component Object Model](https://attack.mitre.org/techniques/T1021/003) and [Component Object Model](https://attack.mitre.org/techniques/T1559/001).**
comment: **This technique has been deprecated. Please use [Distributed Component Object Model](https://attack.mitre.org/techniques/T1021/003) and [Component Object Model](https://attack.mitre.org/techniques/T1559/001).**
deprecated: true

Browser Extensions
type: Class
subclass of: Persistence Technique
subclass of: Restriction
  on property: modifies
  some values from: Browser Extension
type: NamedIndividual
modifies: Browser Extension
attack-id: T1176
definition: Adversaries may abuse Internet browser extensions to establish persistent access to victim systems. Browser extensions or plugins are small programs that can add functionality and customize aspects of Internet browsers. They can be installed directly or through a browser's app store and generally have access and permissions to everything that the browser can access.(Citation: Wikipedia Browser Extension)(Citation: Chrome Extensions Definition)

LSASS Driver
type: Class
subclass of: Execution Technique
subclass of: Persistence Technique
attack-id: T1177
definition: The Windows security subsystem is a set of components that manage and enforce the security policy for a computer or domain. The Local Security Authority (LSA) is the main component responsible for local security policy and user authentication. The LSA includes multiple dynamic link libraries (DLLs) associated with various other security functions, all of which run in the context of the LSA Subsystem Service (LSASS) lsass.exe process. (Citation: Microsoft Security Subsystem)
comment: This technique has been revoked by T1547.008
deprecated: true

SID-History Injection
type: Class
subclass of: Privilege Escalation Technique
attack-id: T1178
definition: The Windows security identifier (SID) is a unique value that identifies a user or group account. SIDs are used by Windows security in both security descriptors and access tokens. (Citation: Microsoft SID) An account can hold additional SIDs in the SID-History Active Directory attribute (Citation: Microsoft SID-History Attribute), allowing inter-operable account migration between domains (e.g., all values in SID-History are included in access tokens).
comment: This technique has been revoked by T1134.005
deprecated: true

Hooking
type: Class
subclass of: Credential Access Technique
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1179
definition: Windows processes often leverage application programming interface (API) functions to perform tasks that require reusable system resources. Windows API functions are typically stored in dynamic-link libraries (DLLs) as exported functions.
comment: This technique has been revoked by T1056.004
deprecated: true

Screensaver
type: Class
subclass of: Persistence Technique
attack-id: T1180
definition: Screensavers are programs that execute after a configurable time of user inactivity and consist of Portable Executable (PE) files with a .scr file extension.(Citation: Wikipedia Screensaver) The Windows screensaver application scrnsave.scr is located in C:\Windows\System32\, and C:\Windows\sysWOW64\ on 64-bit Windows systems, along with screensavers included with base Windows installations.
comment: This technique has been revoked by T1546.002
deprecated: true

Extra Window Memory Injection
type: Class
subclass of: Defense Evasion Technique
subclass of: Privilege Escalation Technique
attack-id: T1181
definition: Before creating a window, graphical Windows-based processes must prescribe to or register a windows class, which stipulate appearance and behavior (via windows procedures, which are functions that handle input/output of data). (Citation: Microsoft Window Classes) Registration of new windows classes can include a request for up to 40 bytes of extra window memory (EWM) to be appended to the allocated memory of each instance of that class. This EWM is intended to store data specific to that window and has specific application programming interface (API) functions to set and get its value. (Citation: Microsoft GetWindowLong function) (Citation: Microsoft SetWindowLong function)
comment: This technique has been revoked by T1055.011
deprecated: true

AppCert DLLs
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1182
definition: Dynamic-link libraries (DLLs) that are specified in the AppCertDLLs Registry key under HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager are loaded into every process that calls the ubiquitously used application programming interface (API) functions CreateProcess, CreateProcessAsUser, CreateProcessWithLoginW, CreateProcessWithTokenW, or WinExec. (Citation: Elastic Process Injection July 2017)
comment: This technique has been revoked by T1546.009
deprecated: true

Image File Execution Options Injection
type: Class
subclass of: Defense Evasion Technique
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1183
definition: Image File Execution Options (IFEO) enable a developer to attach a debugger to an application. When a process is created, a debugger present in an application’s IFEO will be prepended to the application’s name, effectively launching the new process under the debugger (e.g., “C:\dbg\ntsd.exe -g notepad.exe”). (Citation: Microsoft Dev Blog IFEO Mar 2010)
comment: This technique has been revoked by T1546.012
deprecated: true

SSH Hijacking
type: Class
subclass of: Lateral Movement Technique
attack-id: T1184
definition: Secure Shell (SSH) is a standard means of remote access on Linux and macOS systems. It allows a user to connect to another system via an encrypted tunnel, commonly authenticating through a password, certificate or the use of an asymmetric encryption key pair.
comment: This technique has been revoked by T1563.001
deprecated: true

Browser Session Hijacking
type: Class
subclass of: Collection Technique
subclass of: Restriction
  on property: produces
  some values from: Web Network Traffic
type: NamedIndividual
produces: Web Network Traffic
attack-id: T1185
definition: Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.(Citation: Wikipedia Man in the Browser)

Process Doppelgänging
type: Class
subclass of: Defense Evasion Technique
attack-id: T1186
definition: Windows Transactional NTFS (TxF) was introduced in Vista as a method to perform safe file operations. (Citation: Microsoft TxF) To ensure data integrity, TxF enables only one transacted handle to write to a file at a given time. Until the write handle transaction is terminated, all other handles are isolated from the writer and may only read the committed version of the file that existed at the time the handle was opened. (Citation: Microsoft Basic TxF Concepts) To avoid corruption, TxF performs an automatic rollback if the system or application fails during a write transaction. (Citation: Microsoft Where to use TxF)
comment: This technique has been revoked by T1055.013
deprecated: true

Forced Authentication
type: Class
subclass of: Credential Access Technique
subclass of: Restriction
  on property: may-modify
  some values from: Windows Shortcut File
subclass of: Restriction
  on property: modifies
  some values from: Authentication Log
subclass of: Restriction
  on property: produces
  some values from: Authentication
type: NamedIndividual
may-modify: Windows Shortcut File
modifies: Authentication Log
produces: Authentication
attack-id: T1187
definition: Adversaries may gather credential material by invoking or forcing a user to automatically provide authentication information through a mechanism in which they can intercept.

Multi-hop Proxy
type: Class
subclass of: Command and Control Technique
attack-id: T1188
definition: To disguise the source of malicious traffic, adversaries may chain together multiple proxies. Typically, a defender will be able to identify the last proxy traffic traversed before it enters their network; the defender may or may not be able to identify any previous proxies before the last-hop proxy. This technique makes identifying the original source of the malicious traffic even more difficult by requiring the defender to trace malicious traffic through several proxies to identify its source.
comment: This technique has been revoked by T1090.003
deprecated: true

Drive-by Compromise
type: Class
subclass of: Initial Access Technique
subclass of: Restriction
  on property: modifies
  some values from: Process Segment
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Network Traffic
subclass of: Restriction
  on property: produces
  some values from: URL
type: NamedIndividual
modifies: Process Segment
produces: Outbound Internet Network Traffic
produces: URL
attack-id: T1189
definition: Adversaries may gain access to a system through a user visiting a website over the normal course of browsing. With this technique, the user's web browser is typically targeted for exploitation, but adversaries may also use compromised websites for non-exploitation behavior such as acquiring [Application Access Token](https://attack.mitre.org/techniques/T1550/001).

Exploit Public-Facing Application
type: Class
subclass of: Initial Access Technique
subclass of: Restriction
  on property: injects
  some values from: Database Query
subclass of: Restriction
  on property: modifies
  some values from: Process Segment
subclass of: Restriction
  on property: produces
  some values from: Inbound Internet Network Traffic
type: NamedIndividual
injects: Database Query
modifies: Process Segment
produces: Inbound Internet Network Traffic
attack-id: T1190
definition: Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network. The weakness in the system can be a software bug, a temporary glitch, or a misconfiguration.

CMSTP
type: Class
subclass of: Defense Evasion Technique
subclass of: Execution Technique
attack-id: T1191
definition: The Microsoft Connection Manager Profile Installer (CMSTP.exe) is a command-line program used to install Connection Manager service profiles. (Citation: Microsoft Connection Manager Oct 2009) CMSTP.exe accepts an installation information file (INF) as a parameter and installs a service profile leveraged for remote access connections.
comment: This technique has been revoked by T1218.003
deprecated: true

Spearphishing Link
type: Class
subclass of: Initial Access Technique
attack-id: T1192
definition: Spearphishing with a link is a specific variant of spearphishing. It is different from other forms of spearphishing in that it employs the use of links to download malware contained in email, instead of attaching malicious files to the email itself, to avoid defenses that may inspect email attachments.
comment: This technique has been revoked by T1566.002
deprecated: true

Spearphishing Attachment
type: Class
subclass of: Initial Access Technique
attack-id: T1193
definition: Spearphishing attachment is a specific variant of spearphishing. Spearphishing attachment is different from other forms of spearphishing in that it employs the use of malware attached to an email. All forms of spearphishing are electronically delivered social engineering targeted at a specific individual, company, or industry. In this scenario, adversaries attach a file to the spearphishing email and usually rely upon [User Execution](https://attack.mitre.org/techniques/T1204) to gain execution.
comment: This technique has been revoked by T1566.001
deprecated: true

Spearphishing via Service
type: Class
subclass of: Initial Access Technique
attack-id: T1194
definition: Spearphishing via service is a specific variant of spearphishing. It is different from other forms of spearphishing in that it employs the use of third party services rather than directly via enterprise email channels.
comment: This technique has been revoked by T1566.003
deprecated: true

Supply Chain Compromise
type: Class
subclass of: Initial Access Technique
subclass of: Restriction
  on property: modifies
  some values from: Digital Artifact
type: NamedIndividual
modifies: Digital Artifact
attack-id: T1195
definition: Adversaries may manipulate products or product delivery mechanisms prior to receipt by a final consumer for the purpose of data or system compromise.

Compromise Software Dependencies and Development Tools
type: Class
subclass of: Supply Chain Compromise
subclass of: Restriction
  on property: modifies
  some values from: Software
type: NamedIndividual
modifies: Software
attack-id: T1195.001
definition: Adversaries may manipulate software dependencies and development tools prior to receipt by a final consumer for the purpose of data or system compromise. Applications often depend on external software to function properly. Popular open source projects that are used as dependencies in many applications may be targeted as a means to add malicious code to users of the dependency.(Citation: Trendmicro NPM Compromise)

Compromise Software Supply Chain
type: Class
subclass of: Supply Chain Compromise
subclass of: Restriction
  on property: modifies
  some values from: Software
type: NamedIndividual
modifies: Software
attack-id: T1195.002
definition: Adversaries may manipulate application software prior to receipt by a final consumer for the purpose of data or system compromise. Supply chain compromise of software can take place in a number of ways, including manipulation of the application source code, manipulation of the update/distribution mechanism for that software, or replacing compiled releases with a modified version.

Compromise Hardware Supply Chain
type: Class
subclass of: Supply Chain Compromise
subclass of: Restriction
  on property: modifies
  some values from: Hardware Device
type: NamedIndividual
modifies: Hardware Device
attack-id: T1195.003
definition: Adversaries may manipulate hardware components in products prior to receipt by a final consumer for the purpose of data or system compromise. By modifying hardware or firmware in the supply chain, adversaries can insert a backdoor into consumer networks that may be difficult to detect and give the adversary a high degree of control over the system. Hardware backdoors may be inserted into various devices, such as servers, workstations, network infrastructure, or peripherals.

Control Panel Items
type: Class
subclass of: Defense Evasion Technique
subclass of: Execution Technique
attack-id: T1196
definition: Windows Control Panel items are utilities that allow users to view and adjust computer settings. Control Panel items are registered executable (.exe) or Control Panel (.cpl) files, the latter are actually renamed dynamic-link library (.dll) files that export a CPlApplet function. (Citation: Microsoft Implementing CPL) (Citation: TrendMicro CPL Malware Jan 2014) Control Panel items can be executed directly from the command line, programmatically via an application programming interface (API) call, or by simply double-clicking the file. (Citation: Microsoft Implementing CPL) (Citation: TrendMicro CPL Malware Jan 2014) (Citation: TrendMicro CPL Malware Dec 2013)
comment: This technique has been revoked by T1218.002
deprecated: true

BITS Jobs
type: Class
subclass of: Defense Evasion Technique
subclass of: Persistence Technique
subclass of: Restriction
  on property: may-produce
  some values from: Intranet IPC Network Traffic
subclass of: Restriction
  on property: may-produce
  some values from: Intranet Web Network Traffic
subclass of: Restriction
  on property: may-produce
  some values from: Outbound Internet Web Traffic
type: NamedIndividual
may-produce: Intranet IPC Network Traffic
may-produce: Intranet Web Network Traffic
may-produce: Outbound Internet Web Traffic
attack-id: T1197
definition: Adversaries may abuse BITS jobs to persistently execute code and perform various background tasks. Windows Background Intelligent Transfer Service (BITS) is a low-bandwidth, asynchronous file transfer mechanism exposed through [Component Object Model](https://attack.mitre.org/techniques/T1559/001) (COM).(Citation: Microsoft COM)(Citation: Microsoft BITS) BITS is commonly used by updaters, messengers, and other applications preferred to operate in the background (using available idle bandwidth) without interrupting other networked applications. File transfer tasks are implemented as BITS jobs, which contain a queue of one or more file operations.

SIP and Trust Provider Hijacking
type: Class
subclass of: Defense Evasion Technique
subclass of: Persistence Technique
attack-id: T1198
definition: In user mode, Windows Authenticode (Citation: Microsoft Authenticode) digital signatures are used to verify a file's origin and integrity, variables that may be used to establish trust in signed code (ex: a driver with a valid Microsoft signature may be handled as safe). The signature validation process is handled via the WinVerifyTrust application programming interface (API) function, (Citation: Microsoft WinVerifyTrust) which accepts an inquiry and coordinates with the appropriate trust provider, which is responsible for validating parameters of a signature. (Citation: SpectorOps Subverting Trust Sept 2017)
comment: This technique has been revoked by T1553.003
deprecated: true

Trusted Relationship
type: Class
subclass of: Initial Access Technique
subclass of: Restriction
  on property: creates
  some values from: Login Session
subclass of: Restriction
  on property: produces
  some values from: Intranet Network Traffic
type: NamedIndividual
creates: Login Session
produces: Intranet Network Traffic
attack-id: T1199
definition: Adversaries may breach or otherwise leverage organizations who have access to intended victims. Access through trusted third party relationship abuses an existing connection that may not be protected or receives less scrutiny than standard mechanisms of gaining access to a network.

Hardware Additions
type: Class
subclass of: Initial Access Technique
subclass of: Restriction
  on property: connects
  some values from: Hardware Device
type: NamedIndividual
connects: Hardware Device
attack-id: T1200
definition: Adversaries may introduce computer accessories, networking hardware, or other computing devices into a system or network that can be used as a vector to gain access. Rather than just connecting and distributing payloads via removable storage (i.e. [Replication Through Removable Media](https://attack.mitre.org/techniques/T1091)), more robust hardware additions can be used to introduce new functionalities and/or features into a system that can then be abused.

Password Policy Discovery
type: Class
subclass of: Discovery Technique
attack-id: T1201
definition: Adversaries may attempt to access detailed information about the password policy used within an enterprise network or cloud environment. Password policies are a way to enforce complex passwords that are difficult to guess or crack through [Brute Force](https://attack.mitre.org/techniques/T1110). This information may help the adversary to create a list of common passwords and launch dictionary and/or brute force attacks which adheres to the policy (e.g. if the minimum password length should be 8, then not trying passwords such as 'pass123'; not checking for more than 3-4 passwords per account if the lockout is set to 6 as to not lock out accounts).

Indirect Command Execution
type: Class
subclass of: Defense Evasion Technique
attack-id: T1202
definition: Adversaries may abuse utilities that allow for command execution to bypass security restrictions that limit the use of command-line interpreters. Various Windows utilities may be used to execute commands, possibly without invoking [cmd](https://attack.mitre.org/software/S0106). For example, [Forfiles](https://attack.mitre.org/software/S0193), the Program Compatibility Assistant (pcalua.exe), components of the Windows Subsystem for Linux (WSL), as well as other utilities may invoke the execution of programs and commands from a [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059), Run window, or via scripts. (Citation: VectorSec ForFiles Aug 2017) (Citation: Evi1cg Forfiles Nov 2017)

Exploitation for Client Execution
type: Class
subclass of: Execution Technique
subclass of: Restriction
  on property: modifies
  some values from: Process Code Segment
subclass of: Restriction
  on property: modifies
  some values from: Stack Frame
type: NamedIndividual
modifies: Process Code Segment
modifies: Stack Frame
attack-id: T1203
definition: Adversaries may exploit software vulnerabilities in client applications to execute code. Vulnerabilities can exist in software due to unsecure coding practices that can lead to unanticipated behavior. Adversaries can take advantage of certain vulnerabilities through targeted exploitation for the purpose of arbitrary code execution. Oftentimes the most valuable exploits to an offensive toolkit are those that can be used to obtain code execution on a remote system because they can be used to gain access to that system. Users will expect to see files related to the applications they commonly used to do work, so they are a useful target for exploit research and development because of their high utility.

User Execution
type: Class
subclass of: Execution Technique
attack-id: T1204
definition: An adversary may rely upon specific actions by a user in order to gain execution. Users may be subjected to social engineering to get them to execute malicious code by, for example, opening a malicious document file or link. These user actions will typically be observed as follow-on behavior from forms of [Phishing](https://attack.mitre.org/techniques/T1566).

Malicious Link
type: Class
subclass of: User Execution
subclass of: Restriction
  on property: accesses
  some values from: URL
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Web Traffic
type: NamedIndividual
accesses: URL
produces: Outbound Internet Web Traffic
attack-id: T1204.001
definition: An adversary may rely upon a user clicking a malicious link in order to gain execution. Users may be subjected to social engineering to get them to click on a link that will lead to code execution. This user action will typically be observed as follow-on behavior from [Spearphishing Link](https://attack.mitre.org/techniques/T1566/002). Clicking on a link may also lead to other execution techniques such as exploitation of a browser or application vulnerability via [Exploitation for Client Execution](https://attack.mitre.org/techniques/T1203). Links may also lead users to download files that require execution via [Malicious File](https://attack.mitre.org/techniques/T1204/002).

Malicious File
type: Class
subclass of: User Execution
subclass of: Restriction
  on property: executes
  some values from: Executable File
type: NamedIndividual
executes: Executable File
attack-id: T1204.002
definition: An adversary may rely upon a user opening a malicious file in order to gain execution. Users may be subjected to social engineering to get them to open a file that will lead to code execution. This user action will typically be observed as follow-on behavior from [Spearphishing Attachment](https://attack.mitre.org/techniques/T1566/001). Adversaries may use several types of files that require a user to execute them, including .doc, .pdf, .xls, .rtf, .scr, .exe, .lnk, .pif, and .cpl.

Malicious Image
type: Class
subclass of: User Execution
attack-id: T1204.003
definition: Adversaries may rely on a user running a malicious image to facilitate execution. Amazon Web Services (AWS) Amazon Machine Images (AMIs), Google Cloud Platform (GCP) Images, and Azure Images as well as popular container runtimes such as Docker can be backdoored. Backdoored images may be uploaded to a public repository via [Upload Malware](https://attack.mitre.org/techniques/T1608/001), and users may then download and deploy an instance or container from the image without realizing the image is malicious, thus bypassing techniques that specifically achieve Initial Access. This can lead to the execution of malicious code, such as code that executes cryptocurrency mining, in the instance or container.(Citation: Summit Route Malicious AMIs)

Traffic Signaling
type: Class
subclass of: Command and Control Technique
subclass of: Defense Evasion Technique
subclass of: Persistence Technique
subclass of: Restriction
  on property: produces
  some values from: Network Traffic
type: NamedIndividual
produces: Network Traffic
attack-id: T1205
definition: Adversaries use traffic signaling techniques, such as sending specific network sequences or magic packets, to covertly trigger actions like opening ports, activating backdoors, or installing filters, facilitating command and control, persistence, and defense evasion.

Port Knocking
type: Class
subclass of: Traffic Signaling
subclass of: Restriction
  on property: produces
  some values from: Network Traffic
type: NamedIndividual
produces: Network Traffic
attack-id: T1205.001
definition: Adversaries may use port knocking to hide open ports used for persistence or command and control. To enable a port, an adversary sends a series of attempted connections to a predefined sequence of closed ports. After the sequence is completed, opening a port is often accomplished by the host based firewall, but could also be implemented by custom software.

Socket Filters
type: Class
subclass of: Traffic Signaling
attack-id: T1205.002
definition: Adversaries may attach filters to a network socket to monitor then activate backdoors used for persistence or command and control. With elevated permissions, adversaries can use features such as the `libpcap` library to open sockets and install filters to allow or disallow certain types of data to come through the socket. The filter may apply to all traffic passing through the specified network interface (or every interface if not specified). When the network interface receives a packet matching the filter criteria, additional actions can be triggered on the host, such as activation of a reverse shell.

Sudo Caching
type: Class
subclass of: Privilege Escalation Technique
attack-id: T1206
definition: The sudo command "allows a system administrator to delegate authority to give certain users (or groups of users) the ability to run some (or all) commands as root or another user while providing an audit trail of the commands and their arguments." (Citation: sudo man page 2018) Since sudo was made for the system administrator, it has some useful configuration features such as a timestamp_timeout that is the amount of time in minutes between instances of sudo before it will re-prompt for a password. This is because sudo has the ability to cache credentials for a period of time. Sudo creates (or touches) a file at /var/db/sudo with a timestamp of when sudo was last run to determine this timeout. Additionally, there is a tty_tickets variable that treats each new tty (terminal session) in isolation. This means that, for example, the sudo timeout of one tty will not affect another tty (you will have to type the password again).
comment: This technique has been revoked by T1548.003
deprecated: true

Rogue Domain Controller
type: Class
subclass of: Defense Evasion Technique
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database
subclass of: Restriction
  on property: produces
  some values from: Intranet Administrative Network Traffic
type: NamedIndividual
modifies: System Configuration Database
produces: Intranet Administrative Network Traffic
attack-id: T1207
definition: Adversaries may register a rogue Domain Controller to enable manipulation of Active Directory data. DCShadow may be used to create a rogue Domain Controller (DC). DCShadow is a method of manipulating Active Directory (AD) data, including objects and schemas, by registering (or reusing an inactive registration) and simulating the behavior of a DC. (Citation: DCShadow Blog) Once registered, a rogue DC may be able to inject and replicate changes into AD infrastructure for any domain object, including credentials and keys.

Kerberoasting
type: Class
subclass of: Credential Access Technique
attack-id: T1208
definition: Service principal names (SPNs) are used to uniquely identify each instance of a Windows service. To enable authentication, Kerberos requires that SPNs be associated with at least one service logon account (an account specifically tasked with running a service (Citation: Microsoft Detecting Kerberoasting Feb 2018)). (Citation: Microsoft SPN) (Citation: Microsoft SetSPN) (Citation: SANS Attacking Kerberos Nov 2014) (Citation: Harmj0y Kerberoast Nov 2016)
comment: This technique has been revoked by T1558.003
deprecated: true

Time Providers
type: Class
subclass of: Persistence Technique
attack-id: T1209
definition: The Windows Time service (W32Time) enables time synchronization across and within domains. (Citation: Microsoft W32Time Feb 2018) W32Time time providers are responsible for retrieving time stamps from hardware/network resources and outputting these values to other network clients. (Citation: Microsoft TimeProvider)
comment: This technique has been revoked by T1547.003
deprecated: true

Exploitation of Remote Services
type: Class
subclass of: Lateral Movement Technique
subclass of: Restriction
  on property: may-modify
  some values from: Process Code Segment
subclass of: Restriction
  on property: may-modify
  some values from: Process Segment
subclass of: Restriction
  on property: may-modify
  some values from: Stack Frame
subclass of: Restriction
  on property: produces
  some values from: Intranet Network Traffic
type: NamedIndividual
may-modify: Process Code Segment
may-modify: Process Segment
may-modify: Stack Frame
produces: Intranet Network Traffic
attack-id: T1210
definition: Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network. Exploitation of a software vulnerability occurs when an adversary takes advantage of a programming error in a program, service, or within the operating system software or kernel itself to execute adversary-controlled code. A common goal for post-compromise exploitation of remote services is for lateral movement to enable access to a remote system.

Exploitation for Defense Evasion
type: Class
subclass of: Defense Evasion Technique
subclass of: Restriction
  on property: may-modify
  some values from: Process Code Segment
subclass of: Restriction
  on property: may-modify
  some values from: Stack Frame
type: NamedIndividual
may-modify: Process Code Segment
may-modify: Stack Frame
attack-id: T1211
definition: Adversaries may exploit a system or application vulnerability to bypass security features. Exploitation of a vulnerability occurs when an adversary takes advantage of a programming error in a program, service, or within the operating system software or kernel itself to execute adversary-controlled code. Vulnerabilities may exist in defensive security software that can be used to disable or circumvent them.

Exploitation for Credential Access
type: Class
subclass of: Credential Access Technique
subclass of: Restriction
  on property: may-access
  some values from: Authentication Service
subclass of: Restriction
  on property: may-access
  some values from: Credential Management System
subclass of: Restriction
  on property: may-modify
  some values from: Process Code Segment
subclass of: Restriction
  on property: may-modify
  some values from: Stack Frame
type: NamedIndividual
may-access: Authentication Service
may-access: Credential Management System
may-modify: Process Code Segment
may-modify: Stack Frame
attack-id: T1212
definition: Adversaries may exploit software vulnerabilities in an attempt to collect credentials. Exploitation of a software vulnerability occurs when an adversary takes advantage of a programming error in a program, service, or within the operating system software or kernel itself to execute adversary-controlled code.

Data from Information Repositories
type: Class
subclass of: Collection Technique
subclass of: Discovery Technique
subclass of: Restriction
  on property: accesses
  some values from: Resource
type: NamedIndividual
accesses: Resource
attack-id: T1213
definition: Adversaries may leverage information repositories to mine valuable information. Information repositories are tools that allow for storage of information, typically to facilitate collaboration or information sharing between users, and can store a wide variety of data that may aid adversaries in further objectives, or direct access to the target information. Adversaries may also abuse external sharing features to share sensitive documents with recipients outside of the organization.

Confluence
type: Class
subclass of: Data from Information Repositories
subclass of: Restriction
  on property: accesses
  some values from: Web File Resource
type: NamedIndividual
accesses: Web File Resource
attack-id: T1213.001

Sharepoint
type: Class
subclass of: Data from Information Repositories
subclass of: Restriction
  on property: accesses
  some values from: Web File Resource
type: NamedIndividual
accesses: Web File Resource
attack-id: T1213.002
definition: Adversaries may leverage the SharePoint repository as a source to mine valuable information. SharePoint will often contain useful information for an adversary to learn about the structure and functionality of the internal network and systems. For example, the following is a list of example information that may hold potential value to an adversary and may also be found on SharePoint:

Code Repositories
type: Class
subclass of: Data from Information Repositories
subclass of: Restriction
  on property: reads
  some values from: Code Repository
type: NamedIndividual
reads: Code Repository
attack-id: T1213.003
definition: Adversaries may leverage code repositories to collect valuable information. Code repositories are tools/services that store source code and automate software builds. They may be hosted internally or privately on third party sites such as Github, GitLab, SourceForge, and BitBucket. Users typically interact with code repositories through a web application or command-line utilities such as git.

Customer Relationship Management Software
type: Class
subclass of: Data from Information Repositories
attack-id: T1213.004
definition: Adversaries may leverage Customer Relationship Management (CRM) software to mine valuable information. CRM software is used to assist organizations in tracking and managing customer interactions, as well as storing customer data.

Messaging Applications
type: Class
subclass of: Data from Information Repositories
attack-id: T1213.005
definition: Adversaries may leverage chat and messaging applications, such as Microsoft Teams, Google Chat, and Slack, to mine valuable information.

Credentials in Registry
type: Class
subclass of: Credential Access Technique
attack-id: T1214
definition: The Windows Registry stores configuration information that can be used by the system or other programs. Adversaries may query the Registry looking for credentials and passwords that have been stored for use by other programs or services. Sometimes these credentials are used for automatic logons.
comment: This technique has been revoked by T1552.002
deprecated: true

Kernel Modules and Extensions
type: Class
subclass of: Persistence Technique
attack-id: T1215
definition: Loadable Kernel Modules (or LKMs) are pieces of code that can be loaded and unloaded into the kernel upon demand. They extend the functionality of the kernel without the need to reboot the system. For example, one type of module is the device driver, which allows the kernel to access hardware connected to the system. (Citation: Linux Kernel Programming) When used maliciously, Loadable Kernel Modules (LKMs) can be a type of kernel-mode [Rootkit](https://attack.mitre.org/techniques/T1014) that run with the highest operating system privilege (Ring 0). (Citation: Linux Kernel Module Programming Guide) Adversaries can use loadable kernel modules to covertly persist on a system and evade defenses. Examples have been found in the wild and there are some open source projects. (Citation: Volatility Phalanx2) (Citation: CrowdStrike Linux Rootkit) (Citation: GitHub Reptile) (Citation: GitHub Diamorphine)
comment: This technique has been revoked by T1547.006
deprecated: true

System Script Proxy Execution
type: Class
subclass of: Defense Evasion Technique
subclass of: Execution Technique
attack-id: T1216
definition: Adversaries may use trusted scripts, often signed with certificates, to proxy the execution of malicious files. Several Microsoft signed scripts that have been downloaded from Microsoft or are default on Windows installations can be used to proxy execution of other files.(Citation: LOLBAS Project) This behavior may be abused by adversaries to execute malicious files that could bypass application control and signature validation on systems.(Citation: GitHub Ultimate AppLocker Bypass List)

PubPrn
type: Class
subclass of: System Script Proxy Execution
attack-id: T1216.001
definition: Adversaries may use PubPrn to proxy execution of malicious remote files. PubPrn.vbs is a [Visual Basic](https://attack.mitre.org/techniques/T1059/005) script that publishes a printer to Active Directory Domain Services. The script may be signed by Microsoft and is commonly executed through the [Windows Command Shell](https://attack.mitre.org/techniques/T1059/003) via Cscript.exe. For example, the following code publishes a printer within the specified domain: cscript pubprn Printer1 LDAP://CN=Container1,DC=Domain1,DC=Com.(Citation: pubprn)

SyncAppvPublishingServer
type: Class
subclass of: System Script Proxy Execution
attack-id: T1216.002
definition: Adversaries may abuse SyncAppvPublishingServer.vbs to proxy execution of malicious [PowerShell](https://attack.mitre.org/techniques/T1059/001) commands. SyncAppvPublishingServer.vbs is a Visual Basic script associated with how Windows virtualizes applications (Microsoft Application Virtualization, or App-V).(Citation: 1 - appv) For example, Windows may render Win32 applications to users as virtual applications, allowing users to launch and interact with them as if they were installed locally.(Citation: 2 - appv)(Citation: 3 - appv)

Browser Information Discovery
type: Class
subclass of: Discovery Technique
attack-id: T1217
definition: Adversaries may enumerate information about browsers to learn more about compromised environments. Data saved by browsers (such as bookmarks, accounts, and browsing history) may reveal a variety of personal information about users (e.g., banking sites, relationships/interests, social media, etc.) as well as details about internal network resources such as servers, tools/dashboards, or other related infrastructure.(Citation: Kaspersky Autofill)

System Binary Proxy Execution
type: Class
subclass of: Defense Evasion Technique
subclass of: Execution Technique
attack-id: T1218
definition: Adversaries may bypass process and/or signature-based defenses by proxying execution of malicious content with signed, or otherwise trusted, binaries. Binaries used in this technique are often Microsoft-signed files, indicating that they have been either downloaded from Microsoft or are already native in the operating system.(Citation: LOLBAS Project) Binaries signed with trusted digital certificates can typically execute on Windows systems protected by digital signature validation. Several Microsoft signed binaries that are default on Windows installations can be used to proxy execution of other files or commands.

Compiled HTML File
type: Class
subclass of: System Binary Proxy Execution
subclass of: Restriction
  on property: invokes
  some values from: Create File
subclass of: Restriction
  on property: invokes
  some values from: Create Process
type: NamedIndividual
invokes: Create File
invokes: Create Process
attack-id: T1218.001
definition: Adversaries may abuse Compiled HTML files (.chm) to conceal malicious code. CHM files are commonly distributed as part of the Microsoft HTML Help system. CHM files are compressed compilations of various content such as HTML documents, images, and scripting/web related programming languages such VBA, JScript, Java, and ActiveX. (Citation: Microsoft HTML Help May 2018) CHM content is displayed using underlying components of the Internet Explorer browser (Citation: Microsoft HTML Help ActiveX) loaded by the HTML Help executable program (hh.exe). (Citation: Microsoft HTML Help Executable Program)

Control Panel
type: Class
subclass of: System Binary Proxy Execution
subclass of: Restriction
  on property: invokes
  some values from: Create Process
subclass of: Restriction
  on property: may-modify
  some values from: System Configuration Database Record
type: NamedIndividual
invokes: Create Process
may-modify: System Configuration Database Record
attack-id: T1218.002
definition: Adversaries may abuse control.exe to proxy execution of malicious payloads. The Windows Control Panel process binary (control.exe) handles execution of Control Panel items, which are utilities that allow users to view and adjust computer settings.

CMSTP
type: Class
subclass of: System Binary Proxy Execution
subclass of: Restriction
  on property: invokes
  some values from: Create Process
subclass of: Restriction
  on property: may-produce
  some values from: Network Traffic
type: NamedIndividual
invokes: Create Process
may-produce: Network Traffic
attack-id: T1218.003
definition: Adversaries may abuse CMSTP to proxy execution of malicious code. The Microsoft Connection Manager Profile Installer (CMSTP.exe) is a command-line program used to install Connection Manager service profiles. (Citation: Microsoft Connection Manager Oct 2009) CMSTP.exe accepts an installation information file (INF) as a parameter and installs a service profile leveraged for remote access connections.

InstallUtil
type: Class
subclass of: System Binary Proxy Execution
attack-id: T1218.004
definition: Adversaries may use InstallUtil to proxy execution of code through a trusted Windows utility. InstallUtil is a command-line utility that allows for installation and uninstallation of resources by executing specific installer components specified in .NET binaries. (Citation: MSDN InstallUtil) The InstallUtil binary may also be digitally signed by Microsoft and located in the .NET directories on a Windows system: C:\Windows\Microsoft.NET\Framework\v<version>\InstallUtil.exe and C:\Windows\Microsoft.NET\Framework64\v<version>\InstallUtil.exe.

Mshta
type: Class
subclass of: System Binary Proxy Execution
subclass of: Restriction
  on property: interprets
  some values from: Microsoft HTML Application
subclass of: Restriction
  on property: invokes
  some values from: Create Process
type: NamedIndividual
interprets: Microsoft HTML Application
invokes: Create Process
attack-id: T1218.005
definition: Adversaries may abuse mshta.exe to proxy execution of malicious .hta files and Javascript or VBScript through a trusted Windows utility. There are several examples of different types of threats leveraging mshta.exe during initial compromise and for execution of code (Citation: Cylance Dust Storm) (Citation: Red Canary HTA Abuse Part Deux) (Citation: FireEye Attacks Leveraging HTA) (Citation: Airbus Security Kovter Analysis) (Citation: FireEye FIN7 April 2017)

Msiexec
type: Class
subclass of: System Binary Proxy Execution
attack-id: T1218.007
definition: Adversaries may abuse msiexec.exe to proxy execution of malicious payloads. Msiexec.exe is the command-line utility for the Windows Installer and is thus commonly associated with executing installation packages (.msi).(Citation: Microsoft msiexec) The Msiexec.exe binary may also be digitally signed by Microsoft.

Odbcconf
type: Class
subclass of: System Binary Proxy Execution
attack-id: T1218.008
definition: Adversaries may abuse odbcconf.exe to proxy execution of malicious payloads. Odbcconf.exe is a Windows utility that allows you to configure Open Database Connectivity (ODBC) drivers and data source names.(Citation: Microsoft odbcconf.exe) The Odbcconf.exe binary may be digitally signed by Microsoft.

Regsvcs/Regasm
type: Class
subclass of: System Binary Proxy Execution
attack-id: T1218.009
definition: Adversaries may abuse Regsvcs and Regasm to proxy execution of code through a trusted Windows utility. Regsvcs and Regasm are Windows command-line utilities that are used to register .NET [Component Object Model](https://attack.mitre.org/techniques/T1559/001) (COM) assemblies. Both are binaries that may be digitally signed by Microsoft. (Citation: MSDN Regsvcs) (Citation: MSDN Regasm)

Regsvr32
type: Class
subclass of: System Binary Proxy Execution
attack-id: T1218.010
definition: Adversaries may abuse Regsvr32.exe to proxy execution of malicious code. Regsvr32.exe is a command-line program used to register and unregister object linking and embedding controls, including dynamic link libraries (DLLs), on Windows systems. The Regsvr32.exe binary may also be signed by Microsoft. (Citation: Microsoft Regsvr32)

Rundll32
type: Class
subclass of: System Binary Proxy Execution
subclass of: Restriction
  on property: invokes
  some values from: Create Process
subclass of: Restriction
  on property: loads
  some values from: Shared Library File
type: NamedIndividual
invokes: Create Process
loads: Shared Library File
attack-id: T1218.011
definition: Adversaries may abuse rundll32.exe to proxy execution of malicious code. Using rundll32.exe, vice executing directly (i.e. [Shared Modules](https://attack.mitre.org/techniques/T1129)), may avoid triggering security tools that may not monitor execution of the rundll32.exe process because of allowlists or false positives from normal operations. Rundll32.exe is commonly associated with executing DLL payloads (ex: rundll32.exe {DLLname, DLLfunction}).

Verclsid
type: Class
subclass of: System Binary Proxy Execution
attack-id: T1218.012
definition: Adversaries may abuse verclsid.exe to proxy execution of malicious code. Verclsid.exe is known as the Extension CLSID Verification Host and is responsible for verifying each shell extension before they are used by Windows Explorer or the Windows Shell.(Citation: WinOSBite verclsid.exe)

Mavinject
type: Class
subclass of: System Binary Proxy Execution
subclass of: Restriction
  on property: invokes
  some values from: Create Thread
subclass of: Restriction
  on property: modifies
  some values from: Process Segment
type: NamedIndividual
invokes: Create Thread
modifies: Process Segment
attack-id: T1218.013
definition: Adversaries may abuse mavinject.exe to proxy execution of malicious code. Mavinject.exe is the Microsoft Application Virtualization Injector, a Windows utility that can inject code into external processes as part of Microsoft Application Virtualization (App-V).(Citation: LOLBAS Mavinject)

MMC
type: Class
subclass of: System Binary Proxy Execution
subclass of: Restriction
  on property: executes
  some values from: Command
subclass of: Restriction
  on property: may-add
  some values from: Software
subclass of: Restriction
  on property: may-modify
  some values from: System Configuration Database
type: NamedIndividual
executes: Command
may-add: Software
may-modify: System Configuration Database
attack-id: T1218.014
definition: Adversaries may abuse mmc.exe to proxy execution of malicious .msc files. Microsoft Management Console (MMC) is a binary that may be signed by Microsoft and is used in several ways in either its GUI or in a command prompt.(Citation: win_mmc)(Citation: what_is_mmc) MMC can be used to create, open, and save custom consoles that contain administrative tools created by Microsoft, called snap-ins. These snap-ins may be used to manage Windows systems locally or remotely. MMC can also be used to open Microsoft created .msc files to manage system configuration.(Citation: win_msc_files_overview)

Electron Applications
type: Class
subclass of: System Binary Proxy Execution
attack-id: T1218.015
definition: Adversaries may abuse components of the Electron framework to execute malicious code. The Electron framework hosts many common applications such as Signal, Slack, and Microsoft Teams.(Citation: Electron 2) Originally developed by GitHub, Electron is a cross-platform desktop application development framework that employs web technologies like JavaScript, HTML, and CSS.(Citation: Electron 3) The Chromium engine is used to display web content and Node.js runs the backend code.(Citation: Electron 1)

Remote Access Software
type: Class
subclass of: Command and Control Technique
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Network Traffic
type: NamedIndividual
produces: Outbound Internet Network Traffic
attack-id: T1219
definition: An adversary may use legitimate desktop support and remote access software to establish an interactive command and control channel to target systems within networks. These services, such as `VNC`, `Team Viewer`, `AnyDesk`, `ScreenConnect`, `LogMein`, `AmmyyAdmin`, and other remote monitoring and management (RMM) tools, are commonly used as legitimate technical support software and may be allowed by application control within a target environment.(Citation: Symantec Living off the Land)(Citation: CrowdStrike 2015 Global Threat Report)(Citation: CrySyS Blog TeamSpy)

XSL Script Processing
type: Class
subclass of: Defense Evasion Technique
subclass of: Restriction
  on property: adds
  some values from: File
subclass of: Restriction
  on property: interprets
  some values from: Executable Script
subclass of: Restriction
  on property: invokes
  some values from: Create Process
type: NamedIndividual
adds: File
interprets: Executable Script
invokes: Create Process
attack-id: T1220
definition: Adversaries may bypass application control and obscure execution of code by embedding scripts inside XSL files. Extensible Stylesheet Language (XSL) files are commonly used to describe the processing and rendering of data within XML files. To support complex operations, the XSL standard includes support for embedded scripting in various languages. (Citation: Microsoft XSLT Script Mar 2017)

Template Injection
type: Class
subclass of: Defense Evasion Technique
attack-id: T1221
definition: Adversaries may create or modify references in user document templates to conceal malicious code or force authentication attempts. For example, Microsoft’s Office Open XML (OOXML) specification defines an XML-based format for Office documents (.docx, xlsx, .pptx) to replace older binary formats (.doc, .xls, .ppt). OOXML files are packed together ZIP archives compromised of various XML files, referred to as parts, containing properties that collectively define how a document is rendered.(Citation: Microsoft Open XML July 2017)

File and Directory Permissions Modification
type: Class
subclass of: Defense Evasion Technique
subclass of: Restriction
  on property: modifies
  some values from: Access Control Configuration
type: NamedIndividual
modifies: Access Control Configuration
attack-id: T1222
definition: Adversaries may modify file or directory permissions/attributes to evade access control lists (ACLs) and access protected files.(Citation: Hybrid Analysis Icacls1 June 2018)(Citation: Hybrid Analysis Icacls2 May 2018) File and directory permissions are commonly managed by ACLs configured by the file or directory owner, or users with the appropriate permissions. File and directory ACL implementations vary by platform, but generally explicitly designate which users or groups can perform which actions (read, write, execute, etc.).

Windows File and Directory Permissions Modification
type: Class
subclass of: File and Directory Permissions Modification
attack-id: T1222.001
definition: Adversaries may modify file or directory permissions/attributes to evade access control lists (ACLs) and access protected files.(Citation: Hybrid Analysis Icacls1 June 2018)(Citation: Hybrid Analysis Icacls2 May 2018) File and directory permissions are commonly managed by ACLs configured by the file or directory owner, or users with the appropriate permissions. File and directory ACL implementations vary by platform, but generally explicitly designate which users or groups can perform which actions (read, write, execute, etc.).

Linux and Mac File and Directory Permissions Modification
type: Class
subclass of: File and Directory Permissions Modification
attack-id: T1222.002
definition: Adversaries may modify file or directory permissions/attributes to evade access control lists (ACLs) and access protected files.(Citation: Hybrid Analysis Icacls1 June 2018)(Citation: Hybrid Analysis Icacls2 May 2018) File and directory permissions are commonly managed by ACLs configured by the file or directory owner, or users with the appropriate permissions. File and directory ACL implementations vary by platform, but generally explicitly designate which users or groups can perform which actions (read, write, execute, etc.).

Compiled HTML File
type: Class
subclass of: Defense Evasion Technique
subclass of: Execution Technique
attack-id: T1223
definition: Compiled HTML files (.chm) are commonly distributed as part of the Microsoft HTML Help system. CHM files are compressed compilations of various content such as HTML documents, images, and scripting/web related programming languages such VBA, JScript, Java, and ActiveX. (Citation: Microsoft HTML Help May 2018) CHM content is displayed using underlying components of the Internet Explorer browser (Citation: Microsoft HTML Help ActiveX) loaded by the HTML Help executable program (hh.exe). (Citation: Microsoft HTML Help Executable Program)
comment: This technique has been revoked by T1218.001
deprecated: true

Execution Guardrails
type: Class
subclass of: Defense Evasion Technique
attack-id: T1480
definition: Adversaries may use execution guardrails to constrain execution or actions based on adversary supplied and environment specific conditions that are expected to be present on the target. Guardrails ensure that a payload only executes against an intended target and reduces collateral damage from an adversary’s campaign.(Citation: FireEye Kevin Mandia Guardrails) Values an adversary can provide about a target system or environment to use as guardrails may include specific network share names, attached physical devices, files, joined Active Directory (AD) domains, and local/external IP addresses.(Citation: FireEye Outlook Dec 2019)

Environmental Keying
type: Class
subclass of: Execution Guardrails
attack-id: T1480.001
definition: Adversaries may environmentally key payloads or other features of malware to evade defenses and constraint execution to a specific target environment. Environmental keying uses cryptography to constrain execution or actions based on adversary supplied environment specific conditions that are expected to be present on the target. Environmental keying is an implementation of [Execution Guardrails](https://attack.mitre.org/techniques/T1480) that utilizes cryptographic techniques for deriving encryption/decryption keys from specific types of values in a given computing environment.(Citation: EK Clueless Agents)

Mutual Exclusion
type: Class
subclass of: Execution Guardrails
attack-id: T1480.002
definition: Adversaries may constrain execution or actions based on the presence of a mutex associated with malware. A mutex is a locking mechanism used to synchronize access to a resource. Only one thread or process can acquire a mutex at a given time.(Citation: Microsoft Mutexes)

Domain Trust Discovery
type: Class
subclass of: Discovery Technique
attack-id: T1482
definition: Adversaries may attempt to gather information on domain trust relationships that may be used to identify lateral movement opportunities in Windows multi-domain/forest environments. Domain trusts provide a mechanism for a domain to allow access to resources based on the authentication procedures of another domain.(Citation: Microsoft Trusts) Domain trusts allow the users of the trusted domain to access resources in the trusting domain. The information discovered may help the adversary conduct [SID-History Injection](https://attack.mitre.org/techniques/T1134/005), [Pass the Ticket](https://attack.mitre.org/techniques/T1550/003), and [Kerberoasting](https://attack.mitre.org/techniques/T1558/003).(Citation: AdSecurity Forging Trust Tickets)(Citation: Harmj0y Domain Trusts) Domain trusts can be enumerated using the `DSEnumerateDomainTrusts()` Win32 API call, .NET methods, and LDAP.(Citation: Harmj0y Domain Trusts) The Windows utility [Nltest](https://attack.mitre.org/software/S0359) is known to be used by adversaries to enumerate domain trusts.(Citation: Microsoft Operation Wilysupply)

Domain Generation Algorithms
type: Class
subclass of: Command and Control Technique
attack-id: T1483
definition: Adversaries may make use of Domain Generation Algorithms (DGAs) to dynamically identify a destination for command and control traffic rather than relying on a list of static IP addresses or domains. This has the advantage of making it much harder for defenders block, track, or take over the command and control channel, as there potentially could be thousands of domains that malware can check for instructions.(Citation: Cybereason Dissecting DGAs)(Citation: Cisco Umbrella DGA)(Citation: Unit 42 DGA Feb 2019)
comment: This technique has been revoked by T1568.002
deprecated: true

Domain or Tenant Policy Modification
type: Class
subclass of: Defense Evasion Technique
subclass of: Privilege Escalation Technique
subclass of: Restriction
  on property: modifies
  some values from: Group Policy
type: NamedIndividual
modifies: Group Policy
attack-id: T1484
definition: Adversaries may modify the configuration settings of a domain or identity tenant to evade defenses and/or escalate privileges in centrally managed environments. Such services provide a centralized means of managing identity resources such as devices and accounts, and often include configuration settings that may apply between domains or tenants such as trust relationships, identity syncing, or identity federation.

Group Policy Modification
type: Class
subclass of: Domain or Tenant Policy Modification
attack-id: T1484.001
definition: Adversaries may modify Group Policy Objects (GPOs) to subvert the intended discretionary access controls for a domain, usually with the intention of escalating privileges on the domain. Group policy allows for centralized management of user and computer settings in Active Directory (AD). GPOs are containers for group policy settings made up of files stored within a predictable network path `\<DOMAIN>\SYSVOL\<DOMAIN>\Policies\`.(Citation: TechNet Group Policy Basics)(Citation: ADSecurity GPO Persistence 2016)

Trust Modification
type: Class
subclass of: Domain or Tenant Policy Modification
attack-id: T1484.002
definition: Adversaries may add new domain trusts, modify the properties of existing domain trusts, or otherwise change the configuration of trust relationships between domains and tenants to evade defenses and/or elevate privileges.Trust details, such as whether or not user identities are federated, allow authentication and authorization properties to apply between domains or tenants for the purpose of accessing shared resources.(Citation: Microsoft - Azure AD Federation) These trust objects may include accounts, credentials, and other authentication material applied to servers, tokens, and domains.

Data Destruction
type: Class
subclass of: Impact Technique
attack-id: T1485
definition: Adversaries may destroy data and files on specific systems or in large numbers on a network to interrupt availability to systems, services, and network resources. Data destruction is likely to render stored data irrecoverable by forensic techniques through overwriting files or data on local and remote drives.(Citation: Symantec Shamoon 2012)(Citation: FireEye Shamoon Nov 2016)(Citation: Palo Alto Shamoon Nov 2016)(Citation: Kaspersky StoneDrill 2017)(Citation: Unit 42 Shamoon3 2018)(Citation: Talos Olympic Destroyer 2018) Common operating system file deletion commands such as del and rm often only remove pointers to files without wiping the contents of the files themselves, making the files recoverable by proper forensic methodology. This behavior is distinct from [Disk Content Wipe](https://attack.mitre.org/techniques/T1561/001) and [Disk Structure Wipe](https://attack.mitre.org/techniques/T1561/002) because individual files are destroyed rather than sections of a storage disk or the disk's logical structure.

Lifecycle-Triggered Deletion
type: Class
subclass of: Data Destruction
attack-id: T1485.001
definition: Adversaries may modify the lifecycle policies of a cloud storage bucket to destroy all objects stored within.

Data Encrypted for Impact
type: Class
subclass of: Impact Technique
attack-id: T1486
definition: Adversaries may encrypt data on target systems or on large numbers of systems in a network to interrupt availability to system and network resources. They can attempt to render stored data inaccessible by encrypting files or data on local and remote drives and withholding access to a decryption key. This may be done in order to extract monetary compensation from a victim in exchange for decryption or a decryption key (ransomware) or to render data permanently inaccessible in cases where the key is not saved or transmitted.(Citation: US-CERT Ransomware 2016)(Citation: FireEye WannaCry 2017)(Citation: US-CERT NotPetya 2017)(Citation: US-CERT SamSam 2018)

Disk Structure Wipe
type: Class
subclass of: Impact Technique
attack-id: T1487
definition: Adversaries may corrupt or wipe the disk data structures on hard drive necessary to boot systems; targeting specific critical systems as well as a large number of systems in a network to interrupt availability to system and network resources.
comment: This technique has been revoked by T1561.002
deprecated: true

Disk Content Wipe
type: Class
subclass of: Impact Technique
attack-id: T1488
definition: Adversaries may erase the contents of storage devices on specific systems as well as large numbers of systems in a network to interrupt availability to system and network resources.
comment: This technique has been revoked by T1561.001
deprecated: true

Service Stop
type: Class
subclass of: Impact Technique
attack-id: T1489
definition: Adversaries may stop or disable services on a system to render those services unavailable to legitimate users. Stopping critical services or processes can inhibit or stop response to an incident or aid in the adversary's overall objectives to cause damage to the environment.(Citation: Talos Olympic Destroyer 2018)(Citation: Novetta Blockbuster)

Inhibit System Recovery
type: Class
subclass of: Impact Technique
attack-id: T1490
definition: Adversaries may delete or remove built-in data and turn off services designed to aid in the recovery of a corrupted system to prevent recovery.(Citation: Talos Olympic Destroyer 2018)(Citation: FireEye WannaCry 2017) This may deny access to available backups and recovery options.

Defacement
type: Class
subclass of: Impact Technique
attack-id: T1491
definition: Adversaries may modify visual content available internally or externally to an enterprise network, thus affecting the integrity of the original content. Reasons for [Defacement](https://attack.mitre.org/techniques/T1491) include delivering messaging, intimidation, or claiming (possibly false) credit for an intrusion. Disturbing or offensive images may be used as a part of [Defacement](https://attack.mitre.org/techniques/T1491) in order to cause user discomfort, or to pressure compliance with accompanying messages.

Internal Defacement
type: Class
subclass of: Defacement
subclass of: Restriction
  on property: modifies
  some values from: Resource
type: NamedIndividual
modifies: Resource
attack-id: T1491.001
definition: An adversary may deface systems internal to an organization in an attempt to intimidate or mislead users, thus discrediting the integrity of the systems. This may take the form of modifications to internal websites, or directly to user systems with the replacement of the desktop wallpaper.(Citation: Novetta Blockbuster) Disturbing or offensive images may be used as a part of [Internal Defacement](https://attack.mitre.org/techniques/T1491/001) in order to cause user discomfort, or to pressure compliance with accompanying messages. Since internally defacing systems exposes an adversary's presence, it often takes place after other intrusion goals have been accomplished.(Citation: Novetta Blockbuster Destructive Malware)

External Defacement
type: Class
subclass of: Defacement
subclass of: Restriction
  on property: modifies
  some values from: Network Resource
type: NamedIndividual
modifies: Network Resource
attack-id: T1491.002
definition: An adversary may deface systems external to an organization in an attempt to deliver messaging, intimidate, or otherwise mislead an organization or users. [External Defacement](https://attack.mitre.org/techniques/T1491/002) may ultimately cause users to distrust the systems and to question/discredit the system’s integrity. Externally-facing websites are a common victim of defacement; often targeted by adversary and hacktivist groups in order to push a political message or spread propaganda.(Citation: FireEye Cyber Threats to Media Industries)(Citation: Kevin Mandia Statement to US Senate Committee on Intelligence)(Citation: Anonymous Hackers Deface Russian Govt Site) [External Defacement](https://attack.mitre.org/techniques/T1491/002) may be used as a catalyst to trigger events, or as a response to actions taken by an organization or government. Similarly, website defacement may also be used as setup, or a precursor, for future attacks such as [Drive-by Compromise](https://attack.mitre.org/techniques/T1189).(Citation: Trend Micro Deep Dive Into Defacement)

Stored Data Manipulation
type: Class
subclass of: Impact Technique
attack-id: T1492
definition: Adversaries may insert, delete, or manipulate data at rest in order to manipulate external outcomes or hide activity.(Citation: FireEye APT38 Oct 2018)(Citation: DOJ Lazarus Sony 2018) By manipulating stored data, adversaries may attempt to affect a business process, organizational understanding, and decision making.
comment: This technique has been revoked by T1565.001
deprecated: true

Transmitted Data Manipulation
type: Class
subclass of: Impact Technique
attack-id: T1493
definition: Adversaries may alter data en route to storage or other systems in order to manipulate external outcomes or hide activity.(Citation: FireEye APT38 Oct 2018)(Citation: DOJ Lazarus Sony 2018) By manipulating transmitted data, adversaries may attempt to affect a business process, organizational understanding, and decision making.
comment: This technique has been revoked by T1565.002
deprecated: true

Runtime Data Manipulation
type: Class
subclass of: Impact Technique
attack-id: T1494
definition: Adversaries may modify systems in order to manipulate the data as it is accessed and displayed to an end user.(Citation: FireEye APT38 Oct 2018)(Citation: DOJ Lazarus Sony 2018) By manipulating runtime data, adversaries may attempt to affect a business process, organizational understanding, and decision making.
comment: This technique has been revoked by T1565.003
deprecated: true

Firmware Corruption
type: Class
subclass of: Impact Technique
attack-id: T1495
definition: Adversaries may overwrite or corrupt the flash memory contents of system BIOS or other firmware in devices attached to a system in order to render them inoperable or unable to boot, thus denying the availability to use the devices and/or the system.(Citation: Symantec Chernobyl W95.CIH) Firmware is software that is loaded and executed from non-volatile memory on hardware devices in order to initialize and manage device functionality. These devices may include the motherboard, hard drive, or video cards.

Resource Hijacking
type: Class
subclass of: Impact Technique
attack-id: T1496
definition: Adversaries may leverage the resources of co-opted systems to complete resource-intensive tasks, which may impact system and/or hosted service availability.

Compute Hijacking
type: Class
subclass of: Resource Hijacking
attack-id: T1496.001
definition: Adversaries may leverage the compute resources of co-opted systems to complete resource-intensive tasks, which may impact system and/or hosted service availability.

Bandwidth Hijacking
type: Class
subclass of: Resource Hijacking
attack-id: T1496.002
definition: Adversaries may leverage the network bandwidth resources of co-opted systems to complete resource-intensive tasks, which may impact system and/or hosted service availability.

SMS Pumping
type: Class
subclass of: Resource Hijacking
attack-id: T1496.003
definition: Adversaries may leverage messaging services for SMS pumping, which may impact system and/or hosted service availability.(Citation: Twilio SMS Pumping) SMS pumping is a type of telecommunications fraud whereby a threat actor first obtains a set of phone numbers from a telecommunications provider, then leverages a victim’s messaging infrastructure to send large amounts of SMS messages to numbers in that set. By generating SMS traffic to their phone number set, a threat actor may earn payments from the telecommunications provider.(Citation: Twilio SMS Pumping Fraud)

Cloud Service Hijacking
type: Class
subclass of: Resource Hijacking
attack-id: T1496.004
definition: Adversaries may leverage compromised software-as-a-service (SaaS) applications to complete resource-intensive tasks, which may impact hosted service availability.

Virtualization/Sandbox Evasion
type: Class
subclass of: Defense Evasion Technique
attack-id: T1497
definition: Adversaries may employ various means to detect and avoid virtualization and analysis environments. This may include changing behaviors based on the results of checks for the presence of artifacts indicative of a virtual machine environment (VME) or sandbox. If the adversary detects a VME, they may alter their malware to disengage from the victim or conceal the core functions of the implant. They may also search for VME artifacts before dropping secondary or additional payloads. Adversaries may use the information learned from [Virtualization/Sandbox Evasion](https://attack.mitre.org/techniques/T1497) during automated discovery to shape follow-on behaviors.(Citation: Deloitte Environment Awareness)

System Checks
type: Class
subclass of: Virtualization/Sandbox Evasion
attack-id: T1497.001
definition: Adversaries may employ various system checks to detect and avoid virtualization and analysis environments. This may include changing behaviors based on the results of checks for the presence of artifacts indicative of a virtual machine environment (VME) or sandbox. If the adversary detects a VME, they may alter their malware to disengage from the victim or conceal the core functions of the implant. They may also search for VME artifacts before dropping secondary or additional payloads. Adversaries may use the information learned from [Virtualization/Sandbox Evasion](https://attack.mitre.org/techniques/T1497) during automated discovery to shape follow-on behaviors.(Citation: Deloitte Environment Awareness)

User Activity Based Checks
type: Class
subclass of: Virtualization/Sandbox Evasion
attack-id: T1497.002
definition: Adversaries may employ various user activity checks to detect and avoid virtualization and analysis environments. This may include changing behaviors based on the results of checks for the presence of artifacts indicative of a virtual machine environment (VME) or sandbox. If the adversary detects a VME, they may alter their malware to disengage from the victim or conceal the core functions of the implant. They may also search for VME artifacts before dropping secondary or additional payloads. Adversaries may use the information learned from [Virtualization/Sandbox Evasion](https://attack.mitre.org/techniques/T1497) during automated discovery to shape follow-on behaviors.(Citation: Deloitte Environment Awareness)

Time Based Evasion
type: Class
subclass of: Virtualization/Sandbox Evasion
subclass of: Restriction
  on property: may-invoke
  some values from: Get System Time
subclass of: Restriction
  on property: may-run
  some values from: System Time Application
type: NamedIndividual
may-invoke: Get System Time
may-run: System Time Application
attack-id: T1497.003
definition: Adversaries may employ various time-based methods to detect and avoid virtualization and analysis environments. This may include enumerating time-based properties, such as uptime or the system clock, as well as the use of timers or other triggers to avoid a virtual machine environment (VME) or sandbox, specifically those that are automated or only operate for a limited amount of time.

Network Denial of Service
type: Class
subclass of: Impact Technique
attack-id: T1498
definition: Adversaries may perform Network Denial of Service (DoS) attacks to degrade or block the availability of targeted resources to users. Network DoS can be performed by exhausting the network bandwidth services rely on. Example resources include specific websites, email services, DNS, and web-based applications. Adversaries have been observed conducting network DoS attacks for political purposes(Citation: FireEye OpPoisonedHandover February 2016) and to support other malicious activities, including distraction(Citation: FSISAC FraudNetDoS September 2012), hacktivism, and extortion.(Citation: Symantec DDoS October 2014)

Direct Network Flood
type: Class
subclass of: Network Denial of Service
subclass of: Restriction
  on property: creates
  some values from: Inbound Internet Network Traffic
type: NamedIndividual
creates: Inbound Internet Network Traffic
attack-id: T1498.001
definition: Adversaries may attempt to cause a denial of service (DoS) by directly sending a high-volume of network traffic to a target. This DoS attack may also reduce the availability and functionality of the targeted system(s) and network. [Direct Network Flood](https://attack.mitre.org/techniques/T1498/001)s are when one or more systems are used to send a high-volume of network packets towards the targeted service's network. Almost any network protocol may be used for flooding. Stateless protocols such as UDP or ICMP are commonly used but stateful protocols such as TCP can be used as well.

Reflection Amplification
type: Class
subclass of: Network Denial of Service
subclass of: Restriction
  on property: produces
  some values from: Inbound Internet Network Traffic
type: NamedIndividual
produces: Inbound Internet Network Traffic
attack-id: T1498.002
definition: Adversaries may attempt to cause a denial of service (DoS) by reflecting a high-volume of network traffic to a target. This type of Network DoS takes advantage of a third-party server intermediary that hosts and will respond to a given spoofed source IP address. This third-party server is commonly termed a reflector. An adversary accomplishes a reflection attack by sending packets to reflectors with the spoofed address of the victim. Similar to Direct Network Floods, more than one system may be used to conduct the attack, or a botnet may be used. Likewise, one or more reflectors may be used to focus traffic on the target.(Citation: Cloudflare ReflectionDoS May 2017) This Network DoS attack may also reduce the availability and functionality of the targeted system(s) and network.

Endpoint Denial of Service
type: Class
subclass of: Impact Technique
attack-id: T1499
definition: Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users. Endpoint DoS can be performed by exhausting the system resources those services are hosted on or exploiting the system to cause a persistent crash condition. Example services include websites, email services, DNS, and web-based applications. Adversaries have been observed conducting DoS attacks for political purposes(Citation: FireEye OpPoisonedHandover February 2016) and to support other malicious activities, including distraction(Citation: FSISAC FraudNetDoS September 2012), hacktivism, and extortion.(Citation: Symantec DDoS October 2014)

OS Exhaustion Flood
type: Class
subclass of: Endpoint Denial of Service
attack-id: T1499.001
definition: Adversaries may launch a denial of service (DoS) attack targeting an endpoint's operating system (OS). A system's OS is responsible for managing the finite resources as well as preventing the entire system from being overwhelmed by excessive demands on its capacity. These attacks do not need to exhaust the actual resources on a system; the attacks may simply exhaust the limits and available resources that an OS self-imposes.

Service Exhaustion Flood
type: Class
subclass of: Network Denial of Service
subclass of: Restriction
  on property: produces
  some values from: Inbound Internet Network Traffic
type: NamedIndividual
produces: Inbound Internet Network Traffic
attack-id: T1499.002
definition: Adversaries may target the different network services provided by systems to conduct a denial of service (DoS). Adversaries often target the availability of DNS and web services, however others have been targeted as well.(Citation: Arbor AnnualDoSreport Jan 2018) Web server software can be attacked through a variety of means, some of which apply generally while others are specific to the software being used to provide the service.

Application Exhaustion Flood
type: Class
subclass of: Endpoint Denial of Service
attack-id: T1499.003
definition: Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications. For example, specific features in web applications may be highly resource intensive. Repeated requests to those features may be able to exhaust system resources and deny access to the application or the server itself.(Citation: Arbor AnnualDoSreport Jan 2018)

Application or System Exploitation
type: Class
subclass of: Endpoint Denial of Service
attack-id: T1499.004
definition: Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users. (Citation: Sucuri BIND9 August 2015) Some systems may automatically restart critical applications and services when crashes occur, but they can likely be re-exploited to cause a persistent denial of service (DoS) condition.

Compile After Delivery
type: Class
subclass of: Defense Evasion Technique
attack-id: T1500
definition: Adversaries may attempt to make payloads difficult to discover and analyze by delivering files to victims as uncompiled code. Similar to [Obfuscated Files or Information](https://attack.mitre.org/techniques/T1027), text-based source code files may subvert analysis and scrutiny from protections targeting executables/binaries. These payloads will need to be compiled before execution; typically via native utilities such as csc.exe or GCC/MinGW.(Citation: ClearSky MuddyWater Nov 2018)
comment: This technique has been revoked by T1027.004
deprecated: true

Systemd Service
type: Class
subclass of: Persistence Technique
attack-id: T1501
definition: Systemd services can be used to establish persistence on a Linux system. The systemd service manager is commonly used for managing background daemon processes (also known as services) and other system resources.(Citation: Linux man-pages: systemd January 2014)(Citation: Freedesktop.org Linux systemd 29SEP2018) Systemd is the default initialization (init) system on many Linux distributions starting with Debian 8, Ubuntu 15.04, CentOS 7, RHEL 7, Fedora 15, and replaces legacy init systems including SysVinit and Upstart while remaining backwards compatible with the aforementioned init systems.
comment: This technique has been revoked by T1543.002
deprecated: true

Parent PID Spoofing
type: Class
subclass of: Defense Evasion Technique
subclass of: Privilege Escalation Technique
attack-id: T1502
definition: Adversaries may spoof the parent process identifier (PPID) of a new process to evade process-monitoring defenses or to elevate privileges. New processes are typically spawned directly from their parent, or calling, process unless explicitly specified. One way of explicitly assigning the PPID of a new process is via the CreateProcess API call, which supports a parameter that defines the PPID to use.(Citation: DidierStevens SelectMyParent Nov 2009) This functionality is used by Windows features such as User Account Control (UAC) to correctly set the PPID after a requested elevated process is spawned by SYSTEM (typically via svchost.exe or consent.exe) rather than the current user context.(Citation: Microsoft UAC Nov 2018)
comment: This technique has been revoked by T1134.004
deprecated: true

Credentials from Web Browsers
type: Class
subclass of: Credential Access Technique
attack-id: T1503
definition: Adversaries may acquire credentials from web browsers by reading files specific to the target browser. (Citation: Talos Olympic Destroyer 2018)
comment: This technique has been revoked by T1555.003
deprecated: true

PowerShell Profile
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1504
definition: Adversaries may gain persistence and elevate privileges in certain situations by abusing [PowerShell](https://attack.mitre.org/techniques/T1086) profiles. A PowerShell profile (profile.ps1) is a script that runs when PowerShell starts and can be used as a logon script to customize user environments. PowerShell supports several profiles depending on the user or host program. For example, there can be different profiles for PowerShell host programs such as the PowerShell console, PowerShell ISE or Visual Studio Code. An administrator can also configure a profile that applies to all users and host programs on the local computer. (Citation: Microsoft About Profiles)
comment: This technique has been revoked by T1546.013
deprecated: true

Server Software Component
type: Class
subclass of: Persistence Technique
attack-id: T1505
definition: Adversaries may abuse legitimate extensible development features of servers to establish persistent access to systems. Enterprise server applications may include features that allow developers to write and install software or scripts to extend the functionality of the main application. Adversaries may install malicious components to extend and abuse server applications.(Citation: volexity_0day_sophos_FW)

SQL Stored Procedures
type: Class
subclass of: Server Software Component
subclass of: Restriction
  on property: creates
  some values from: Stored Procedure
subclass of: Restriction
  on property: invokes
  some values from: Create Process
type: NamedIndividual
creates: Stored Procedure
invokes: Create Process
attack-id: T1505.001
definition: Adversaries may abuse SQL stored procedures to establish persistent access to systems. SQL Stored Procedures are code that can be saved and reused so that database users do not waste time rewriting frequently used SQL queries. Stored procedures can be invoked via SQL statements to the database using the procedure name or via defined events (e.g. when a SQL server application is started/restarted).

Transport Agent
type: Class
subclass of: Server Software Component
subclass of: Restriction
  on property: adds
  some values from: Message Transfer Agent
subclass of: Restriction
  on property: modifies
  some values from: Mail Server
type: NamedIndividual
adds: Message Transfer Agent
modifies: Mail Server
attack-id: T1505.002
definition: Adversaries may abuse Microsoft transport agents to establish persistent access to systems. Microsoft Exchange transport agents can operate on email messages passing through the transport pipeline to perform various tasks such as filtering spam, filtering malicious attachments, journaling, or adding a corporate signature to the end of all outgoing emails.(Citation: Microsoft TransportAgent Jun 2016)(Citation: ESET LightNeuron May 2019) Transport agents can be written by application developers and then compiled to .NET assemblies that are subsequently registered with the Exchange server. Transport agents will be invoked during a specified stage of email processing and carry out developer defined tasks.

Web Shell
type: Class
subclass of: Server Software Component
subclass of: Restriction
  on property: adds
  some values from: Web Script File
subclass of: Restriction
  on property: modifies
  some values from: Web Server
subclass of: Restriction
  on property: produces
  some values from: Process
type: NamedIndividual
adds: Web Script File
modifies: Web Server
produces: Process
attack-id: T1505.003
definition: Adversaries may backdoor web servers with web shells to establish persistent access to systems. A Web shell is a Web script that is placed on an openly accessible Web server to allow an adversary to access the Web server as a gateway into a network. A Web shell may provide a set of functions to execute or a command-line interface on the system that hosts the Web server.(Citation: volexity_0day_sophos_FW)

IIS Components
type: Class
subclass of: Server Software Component
subclass of: Restriction
  on property: adds
  some values from: Software
type: NamedIndividual
adds: Software
attack-id: T1505.004
definition: Adversaries may install malicious components that run on Internet Information Services (IIS) web servers to establish persistence. IIS provides several mechanisms to extend the functionality of the web servers. For example, Internet Server Application Programming Interface (ISAPI) extensions and filters can be installed to examine and/or modify incoming and outgoing IIS web requests. Extensions and filters are deployed as DLL files that export three functions: Get{Extension/Filter}Version, Http{Extension/Filter}Proc, and (optionally) Terminate{Extension/Filter}. IIS modules may also be installed to extend IIS web servers.(Citation: Microsoft ISAPI Extension Overview 2017)(Citation: Microsoft ISAPI Filter Overview 2017)(Citation: IIS Backdoor 2011)(Citation: Trustwave IIS Module 2013)

Terminal Services DLL
type: Class
subclass of: Server Software Component
attack-id: T1505.005
definition: Adversaries may abuse components of Terminal Services to enable persistent access to systems. Microsoft Terminal Services, renamed to Remote Desktop Services in some Windows Server OSs as of 2022, enable remote terminal connections to hosts. Terminal Services allows servers to transmit a full, interactive, graphical user interface to clients via RDP.(Citation: Microsoft Remote Desktop Services)

Web Session Cookie
type: Class
subclass of: Defense Evasion Technique
subclass of: Lateral Movement Technique
attack-id: T1506
definition: Adversaries can use stolen session cookies to authenticate to web applications and services. This technique bypasses some multi-factor authentication protocols since the session is already authenticated.(Citation: Pass The Cookie)
comment: This technique has been revoked by T1550.004
deprecated: true

Elevated Execution with Prompt
type: Class
subclass of: Privilege Escalation Technique
attack-id: T1514
definition: Adversaries may leverage the AuthorizationExecuteWithPrivileges API to escalate privileges by prompting the user for credentials.(Citation: AppleDocs AuthorizationExecuteWithPrivileges) The purpose of this API is to give application developers an easy way to perform operations with root privileges, such as for application installation or updating. This API does not validate that the program requesting root privileges comes from a reputable source or has been maliciously modified. Although this API is deprecated, it still fully functions in the latest releases of macOS. When calling this API, the user will be prompted to enter their credentials but no checks on the origin or integrity of the program are made. The program calling the API may also load world writable files which can be modified to perform malicious behavior with elevated privileges.
comment: This technique has been revoked by T1548.004
deprecated: true

Software Discovery
type: Class
subclass of: Discovery Technique
attack-id: T1518
definition: Adversaries may attempt to get a listing of software and software versions that are installed on a system or in a cloud environment. Adversaries may use the information from [Software Discovery](https://attack.mitre.org/techniques/T1518) during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.

Security Software Discovery
type: Class
subclass of: Software Discovery
subclass of: Restriction
  on property: may-access
  some values from: File System Metadata
subclass of: Restriction
  on property: may-access
  some values from: Kernel Process Table
subclass of: Restriction
  on property: may-access
  some values from: System Configuration Database Record
subclass of: Restriction
  on property: may-access
  some values from: System Firewall Configuration
subclass of: Restriction
  on property: may-invoke
  some values from: Get Running Processes
type: NamedIndividual
may-access: File System Metadata
may-access: Kernel Process Table
may-access: System Configuration Database Record
may-access: System Firewall Configuration
may-invoke: Get Running Processes
attack-id: T1518.001
definition: Adversaries may attempt to get a listing of security software, configurations, defensive tools, and sensors that are installed on a system or in a cloud environment. This may include things such as cloud monitoring agents and anti-virus. Adversaries may use the information from [Security Software Discovery](https://attack.mitre.org/techniques/T1518/001) during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.

Emond
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1519
definition: Adversaries may use Event Monitor Daemon (emond) to establish persistence by scheduling malicious commands to run on predictable event triggers. Emond is a [Launch Daemon](https://attack.mitre.org/techniques/T1160) that accepts events from various services, runs them through a simple rules engine, and takes action. The emond binary at /sbin/emond will load any rules from the /etc/emond.d/rules/ directory and take action once an explicitly defined event takes place. The rule files are in the plist format and define the name, event type, and action to take. Some examples of event types include system startup and user authentication. Examples of actions are to run a system command or send an email. The emond service will not launch if there is no file present in the QueueDirectories path /private/var/db/emondClients, specified in the [Launch Daemon](https://attack.mitre.org/techniques/T1160) configuration file at/System/Library/LaunchDaemons/com.apple.emond.plist.(Citation: xorrior emond Jan 2018)(Citation: magnusviri emond Apr 2016)(Citation: sentinelone macos persist Jun 2019)
comment: This technique has been revoked by T1546.014
deprecated: true

Cloud Instance Metadata API
type: Class
subclass of: Credential Access Technique
attack-id: T1522
definition: Adversaries may attempt to access the Cloud Instance Metadata API to collect credentials and other sensitive data.
comment: This technique has been revoked by T1552.005
deprecated: true

Implant Internal Image
type: Class
subclass of: Persistence Technique
subclass of: Restriction
  on property: adds
  some values from: Container Image
type: NamedIndividual
adds: Container Image
attack-id: T1525
definition: Adversaries may implant cloud or container images with malicious code to establish persistence after gaining access to an environment. Amazon Web Services (AWS) Amazon Machine Images (AMIs), Google Cloud Platform (GCP) Images, and Azure Images as well as popular container runtimes such as Docker can be implanted or backdoored. Unlike [Upload Malware](https://attack.mitre.org/techniques/T1608/001), this technique focuses on adversaries implanting an image in a registry within a victim’s environment. Depending on how the infrastructure is provisioned, this could provide persistent access if the infrastructure provisioning tool is instructed to always use the latest image.(Citation: Rhino Labs Cloud Image Backdoor Technique Sept 2019)

Cloud Service Discovery
type: Class
subclass of: Discovery Technique
subclass of: Restriction
  on property: reads
  some values from: Cloud Configuration
type: NamedIndividual
reads: Cloud Configuration
attack-id: T1526
definition: An adversary may attempt to enumerate the cloud services running on a system after gaining access. These methods can differ from platform-as-a-service (PaaS), to infrastructure-as-a-service (IaaS), or software-as-a-service (SaaS). Many services exist throughout the various cloud providers and can include Continuous Integration and Continuous Delivery (CI/CD), Lambda Functions, Azure AD, etc. They may also include security services, such as AWS GuardDuty and Microsoft Defender for Cloud, and logging services, such as AWS CloudTrail and Google Cloud Audit Logs.

Application Access Token
type: Class
subclass of: Defense Evasion Technique
subclass of: Lateral Movement Technique
attack-id: T1527
definition: Adversaries may use application access tokens to bypass the typical authentication process and access restricted accounts, information, or services on remote systems. These tokens are typically stolen from users and used in lieu of login credentials.
comment: This technique has been revoked by T1550.001
deprecated: true

Steal Application Access Token
type: Class
subclass of: Credential Access Technique
subclass of: Restriction
  on property: accesses
  some values from: Access Token
type: NamedIndividual
accesses: Access Token
attack-id: T1528
definition: Adversaries can steal application access tokens as a means of acquiring credentials to access remote systems and resources.

System Shutdown/Reboot
type: Class
subclass of: Impact Technique
attack-id: T1529
definition: Adversaries may shutdown/reboot systems to interrupt access to, or aid in the destruction of, those systems. Operating systems may contain commands to initiate a shutdown/reboot of a machine or network device. In some cases, these commands may also be used to initiate a shutdown/reboot of a remote computer or network device via [Network Device CLI](https://attack.mitre.org/techniques/T1059/008) (e.g. reload).(Citation: Microsoft Shutdown Oct 2017)(Citation: alert_TA18_106A)

Data from Cloud Storage
type: Class
subclass of: Collection Technique
attack-id: T1530
definition: Adversaries may access data from cloud storage.

Account Access Removal
type: Class
subclass of: Impact Technique
subclass of: Restriction
  on property: modifies
  some values from: User Account
type: NamedIndividual
modifies: User Account
attack-id: T1531
definition: Adversaries may interrupt availability of system and network resources by inhibiting access to accounts utilized by legitimate users. Accounts may be deleted, locked, or manipulated (ex: changed credentials) to remove access to accounts. Adversaries may also subsequently log off and/or perform a [System Shutdown/Reboot](https://attack.mitre.org/techniques/T1529) to set malicious changes into place.(Citation: CarbonBlack LockerGoga 2019)(Citation: Unit42 LockerGoga 2019)

Internal Spearphishing
type: Class
subclass of: Lateral Movement Technique
subclass of: Restriction
  on property: produces
  some values from: Email
type: NamedIndividual
produces: Email
attack-id: T1534
definition: After they already have access to accounts or systems within the environment, adversaries may use internal spearphishing to gain access to additional information or compromise other users within the same organization. Internal spearphishing is multi-staged campaign where a legitimate account is initially compromised either by controlling the user's device or by compromising the account credentials of the user. Adversaries may then attempt to take advantage of the trusted internal account to increase the likelihood of tricking more victims into falling for phish attempts, often incorporating [Impersonation](https://attack.mitre.org/techniques/T1656).(Citation: Trend Micro - Int SP)

Unused/Unsupported Cloud Regions
type: Class
subclass of: Defense Evasion Technique
attack-id: T1535
definition: Adversaries may create cloud instances in unused geographic service regions in order to evade detection. Access is usually obtained through compromising accounts used to manage cloud infrastructure.

Revert Cloud Instance
type: Class
subclass of: Defense Evasion Technique
attack-id: T1536
definition: An adversary may revert changes made to a cloud instance after they have performed malicious activities in attempt to evade detection and remove evidence of their presence. In highly virtualized environments, such as cloud-based infrastructure, this may be accomplished by restoring virtual machine (VM) or data storage snapshots through the cloud management dashboard or cloud APIs.
comment: This technique has been revoked by T1578.004
deprecated: true

Transfer Data to Cloud Account
type: Class
subclass of: Exfiltration Technique
attack-id: T1537
definition: Adversaries may exfiltrate data by transferring the data, including through sharing/syncing and creating backups of cloud environments, to another cloud account they control on the same service.

Cloud Service Dashboard
type: Class
subclass of: Discovery Technique
subclass of: Restriction
  on property: accesses
  some values from: Cloud Configuration
type: NamedIndividual
accesses: Cloud Configuration
attack-id: T1538
definition: An adversary may use a cloud service dashboard GUI with stolen credentials to gain useful information from an operational cloud environment, such as specific services, resources, and features. For example, the GCP Command Center can be used to view all assets, findings of potential security risks, and to run additional queries, such as finding public IP addresses and open ports.(Citation: Google Command Center Dashboard)

Steal Web Session Cookie
type: Class
subclass of: Credential Access Technique
subclass of: Restriction
  on property: accesses
  some values from: Session Cookie
type: NamedIndividual
accesses: Session Cookie
attack-id: T1539
definition: An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials. Web applications and services often use session cookies as an authentication token after a user has authenticated to a website.

Pre-OS Boot
type: Class
subclass of: Defense Evasion Technique
subclass of: Persistence Technique
attack-id: T1542
definition: Adversaries may abuse Pre-OS Boot mechanisms as a way to establish persistence on a system. During the booting process of a computer, firmware and various startup services are loaded before the operating system. These programs control flow of execution before the operating system takes control.(Citation: Wikipedia Booting)

System Firmware
type: Class
subclass of: Pre-OS Boot
subclass of: Restriction
  on property: modifies
  some values from: System Firmware
type: NamedIndividual
modifies: System Firmware
attack-id: T1542.001
definition: Adversaries may modify system firmware to persist on systems.The BIOS (Basic Input/Output System) and The Unified Extensible Firmware Interface (UEFI) or Extensible Firmware Interface (EFI) are examples of system firmware that operate as the software interface between the operating system and hardware of a computer.(Citation: Wikipedia BIOS)(Citation: Wikipedia UEFI)(Citation: About UEFI)

Component Firmware
type: Class
subclass of: Pre-OS Boot
subclass of: Restriction
  on property: modifies
  some values from: Firmware
type: NamedIndividual
modifies: Firmware
attack-id: T1542.002
definition: Adversaries may modify component firmware to persist on systems. Some adversaries may employ sophisticated means to compromise computer components and install malicious firmware that will execute adversary code outside of the operating system and main system firmware or BIOS. This technique may be similar to [System Firmware](https://attack.mitre.org/techniques/T1542/001) but conducted upon other system components/devices that may not have the same capability or level of integrity checking.

Bootkit
type: Class
subclass of: Pre-OS Boot
subclass of: Restriction
  on property: may-modify
  some values from: Boot Loader
subclass of: Restriction
  on property: may-modify
  some values from: Boot Sector
subclass of: Restriction
  on property: may-modify
  some values from: Volume Boot Record
type: NamedIndividual
may-modify: Boot Loader
may-modify: Boot Sector
may-modify: Volume Boot Record
attack-id: T1542.003
definition: Adversaries may use bootkits to persist on systems. Bootkits reside at a layer below the operating system and may make it difficult to perform full remediation unless an organization suspects one was used and can act accordingly.

ROMMONkit
type: Class
subclass of: Pre-OS Boot
subclass of: Restriction
  on property: modifies
  some values from: System Firmware
type: NamedIndividual
modifies: System Firmware
attack-id: T1542.004
definition: Adversaries may abuse the ROM Monitor (ROMMON) by loading an unauthorized firmware with adversary code to provide persistent access and manipulate device behavior that is difficult to detect. (Citation: Cisco Synful Knock Evolution)(Citation: Cisco Blog Legacy Device Attacks)

TFTP Boot
type: Class
subclass of: Pre-OS Boot
subclass of: Restriction
  on property: creates
  some values from: TFTP Network Traffic
type: NamedIndividual
creates: TFTP Network Traffic
attack-id: T1542.005
definition: Adversaries may abuse netbooting to load an unauthorized network device operating system from a Trivial File Transfer Protocol (TFTP) server. TFTP boot (netbooting) is commonly used by network administrators to load configuration-controlled network device images from a centralized management server. Netbooting is one option in the boot sequence and can be used to centralize, manage, and control device images.

Create or Modify System Process
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1543
definition: Adversaries may create or modify system-level processes to repeatedly execute malicious payloads as part of persistence. When operating systems boot up, they can start processes that perform background system functions. On Windows and Linux, these system processes are referred to as services.(Citation: TechNet Services) On macOS, launchd processes known as [Launch Daemon](https://attack.mitre.org/techniques/T1543/004) and [Launch Agent](https://attack.mitre.org/techniques/T1543/001) are run to finish system initialization and load user specific parameters.(Citation: AppleDocs Launch Agent Daemons)

Launch Agent
type: Class
subclass of: Create or Modify System Process
subclass of: Restriction
  on property: creates
  some values from: Property List File
type: NamedIndividual
creates: Property List File
attack-id: T1543.001
definition: Adversaries may create or modify launch agents to repeatedly execute malicious payloads as part of persistence. When a user logs in, a per-user launchd process is started which loads the parameters for each launch-on-demand user agent from the property list (.plist) file found in /System/Library/LaunchAgents, /Library/LaunchAgents, and ~/Library/LaunchAgents.(Citation: AppleDocs Launch Agent Daemons)(Citation: OSX Keydnap malware) (Citation: Antiquated Mac Malware) Property list files use the Label, ProgramArguments , and RunAtLoad keys to identify the Launch Agent's name, executable location, and execution time.(Citation: OSX.Dok Malware) Launch Agents are often installed to perform updates to programs, launch user specified programs at login, or to conduct other developer tasks.

Systemd Service
type: Class
subclass of: Create or Modify System Process
subclass of: Restriction
  on property: may-create
  some values from: Operating System Configuration File
subclass of: Restriction
  on property: may-modify
  some values from: Operating System Configuration File
type: NamedIndividual
may-create: Operating System Configuration File
may-modify: Operating System Configuration File
attack-id: T1543.002
definition: Adversaries may create or modify systemd services to repeatedly execute malicious payloads as part of persistence. Systemd is a system and service manager commonly used for managing background daemon processes (also known as services) and other system resources.(Citation: Linux man-pages: systemd January 2014) Systemd is the default initialization (init) system on many Linux distributions replacing legacy init systems, including SysVinit and Upstart, while remaining backwards compatible.

Windows Service
type: Class
subclass of: Create or Modify System Process
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database
type: NamedIndividual
modifies: System Configuration Database
attack-id: T1543.003
definition: Adversaries may create or modify Windows services to repeatedly execute malicious payloads as part of persistence. When Windows boots up, it starts programs or applications called services that perform background system functions.(Citation: TechNet Services) Windows service configuration information, including the file path to the service's executable or recovery programs/commands, is stored in the Windows Registry.

Launch Daemon
type: Class
subclass of: Create or Modify System Process
subclass of: Restriction
  on property: modifies
  some values from: Property List File
type: NamedIndividual
modifies: Property List File
attack-id: T1543.004
definition: Adversaries may create or modify Launch Daemons to execute malicious payloads as part of persistence. Launch Daemons are plist files used to interact with Launchd, the service management framework used by macOS. Launch Daemons require elevated privileges to install, are executed for every user on a system prior to login, and run in the background without the need for user interaction. During the macOS initialization startup, the launchd process loads the parameters for launch-on-demand system-level daemons from plist files found in /System/Library/LaunchDaemons/ and /Library/LaunchDaemons/. Required Launch Daemons parameters include a Label to identify the task, Program to provide a path to the executable, and RunAtLoad to specify when the task is run. Launch Daemons are often used to provide access to shared resources, updates to software, or conduct automation tasks.(Citation: AppleDocs Launch Agent Daemons)(Citation: Methods of Mac Malware Persistence)(Citation: launchd Keywords for plists)

Container Service
type: Class
subclass of: Create or Modify System Process
attack-id: T1543.005
definition: Adversaries may create or modify container or container cluster management tools that run as daemons, agents, or services on individual hosts. These include software for creating and managing individual containers, such as Docker and Podman, as well as container cluster node-level agents such as kubelet. By modifying these services, an adversary may be able to achieve persistence or escalate their privileges on a host.

Event Triggered Execution
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1546
definition: Adversaries may establish persistence and/or elevate privileges using system mechanisms that trigger execution based on specific events. Various operating systems have means to monitor and subscribe to events such as logons or other user activity such as running specific applications/binaries. Cloud environments may also support various functions and services that monitor and can be invoked in response to specific cloud events.(Citation: Backdooring an AWS account)(Citation: Varonis Power Automate Data Exfiltration)(Citation: Microsoft DART Case Report 001)

Change Default File Association
type: Class
subclass of: Event Triggered Execution
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database Record
type: NamedIndividual
modifies: System Configuration Database Record
attack-id: T1546.001
definition: Adversaries may establish persistence by executing malicious content triggered by a file type association. When a file is opened, the default program used to open the file (also called the file association or handler) is checked. File association selections are stored in the Windows Registry and can be edited by users, administrators, or programs that have Registry access or by administrators using the built-in assoc utility.(Citation: Microsoft Change Default Programs)(Citation: Microsoft File Handlers)(Citation: Microsoft Assoc Oct 2017) Applications can modify the file association for a given file extension to call an arbitrary program when a file with the given extension is opened.

Screensaver
type: Class
subclass of: Event Triggered Execution
subclass of: Restriction
  on property: creates
  some values from: Executable File
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database Record
type: NamedIndividual
creates: Executable File
modifies: System Configuration Database Record
attack-id: T1546.002
definition: Adversaries may establish persistence by executing malicious content triggered by user inactivity. Screensavers are programs that execute after a configurable time of user inactivity and consist of Portable Executable (PE) files with a .scr file extension.(Citation: Wikipedia Screensaver) The Windows screensaver application scrnsave.scr is located in C:\Windows\System32\, and C:\Windows\sysWOW64\ on 64-bit Windows systems, along with screensavers included with base Windows installations.

Windows Management Instrumentation Event Subscription
type: Class
subclass of: Event Triggered Execution
subclass of: Restriction
  on property: modifies
  some values from: Event Log
subclass of: Restriction
  on property: produces
  some values from: Intranet Administrative Network Traffic
type: NamedIndividual
modifies: Event Log
produces: Intranet Administrative Network Traffic
attack-id: T1546.003
definition: Adversaries may establish persistence and elevate privileges by executing malicious content triggered by a Windows Management Instrumentation (WMI) event subscription. WMI can be used to install event filters, providers, consumers, and bindings that execute code when a defined event occurs. Examples of events that may be subscribed to are the wall clock time, user login, or the computer's uptime.(Citation: Mandiant M-Trends 2015)

Unix Shell Configuration Modification
type: Class
subclass of: Event Triggered Execution
subclass of: Restriction
  on property: modifies
  some values from: User Init Configuration File
type: NamedIndividual
modifies: User Init Configuration File
attack-id: T1546.004
definition: Adversaries may establish persistence through executing malicious commands triggered by a user’s shell. User [Unix Shell](https://attack.mitre.org/techniques/T1059/004)s execute several configuration scripts at different points throughout the session based on events. For example, when a user opens a command-line interface or remotely logs in (such as via SSH) a login shell is initiated. The login shell executes scripts from the system (/etc) and the user’s home directory (~/) to configure the environment. All login shells on a system use /etc/profile when initiated. These configuration scripts run at the permission level of their directory and are often used to set environment variables, create aliases, and customize the user’s environment. When the shell exits or terminates, additional shell scripts are executed to ensure the shell exits appropriately.

Trap
type: Class
subclass of: Event Triggered Execution
subclass of: Restriction
  on property: executes
  some values from: Command
subclass of: Restriction
  on property: may-create
  some values from: Executable Script
subclass of: Restriction
  on property: may-modify
  some values from: Executable Script
subclass of: Restriction
  on property: modifies
  some values from: Event Log
type: NamedIndividual
executes: Command
may-create: Executable Script
may-modify: Executable Script
modifies: Event Log
attack-id: T1546.005
definition: Adversaries may establish persistence by executing malicious content triggered by an interrupt signal. The trap command allows programs and shells to specify commands that will be executed upon receiving interrupt signals. A common situation is a script allowing for graceful termination and handling of common keyboard interrupts like ctrl+c and ctrl+d.

LC_LOAD_DYLIB Addition
type: Class
subclass of: Event Triggered Execution
subclass of: Restriction
  on property: modifies
  some values from: Executable Binary
type: NamedIndividual
modifies: Executable Binary
attack-id: T1546.006
definition: Adversaries may establish persistence by executing malicious content triggered by the execution of tainted binaries. Mach-O binaries have a series of headers that are used to perform certain operations when a binary is loaded. The LC_LOAD_DYLIB header in a Mach-O binary tells macOS and OS X which dynamic libraries (dylibs) to load during execution time. These can be added ad-hoc to the compiled binary as long as adjustments are made to the rest of the fields and dependencies.(Citation: Writing Bad Malware for OSX) There are tools available to perform these changes.

Netsh Helper DLL
type: Class
subclass of: Event Triggered Execution
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database Record
subclass of: Restriction
  on property: produces
  some values from: Process
type: NamedIndividual
modifies: System Configuration Database Record
produces: Process
attack-id: T1546.007
definition: Adversaries may establish persistence by executing malicious content triggered by Netsh Helper DLLs. Netsh.exe (also referred to as Netshell) is a command-line scripting utility used to interact with the network configuration of a system. It contains functionality to add helper DLLs for extending functionality of the utility.(Citation: TechNet Netsh) The paths to registered netsh.exe helper DLLs are entered into the Windows Registry at HKLM\SOFTWARE\Microsoft\Netsh.

Accessibility Features
type: Class
subclass of: Event Triggered Execution
subclass of: Restriction
  on property: may-create
  some values from: Intranet Administrative Network Traffic
subclass of: Restriction
  on property: may-modify
  some values from: Executable Binary
subclass of: Restriction
  on property: may-modify
  some values from: System Configuration Database Record
type: NamedIndividual
may-create: Intranet Administrative Network Traffic
may-modify: Executable Binary
may-modify: System Configuration Database Record
attack-id: T1546.008
definition: Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by accessibility features. Windows contains accessibility features that may be launched with a key combination before a user has logged in (ex: when the user is on the Windows logon screen). An adversary can modify the way these programs are launched to get a command prompt or backdoor without logging in to the system.

AppCert DLLs
type: Class
subclass of: Event Triggered Execution
subclass of: Restriction
  on property: invokes
  some values from: Create Process
subclass of: Restriction
  on property: loads
  some values from: Shared Library File
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database Record
type: NamedIndividual
invokes: Create Process
loads: Shared Library File
modifies: System Configuration Database Record
attack-id: T1546.009
definition: Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by AppCert DLLs loaded into processes. Dynamic-link libraries (DLLs) that are specified in the AppCertDLLs Registry key under HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\ are loaded into every process that calls the ubiquitously used application programming interface (API) functions CreateProcess, CreateProcessAsUser, CreateProcessWithLoginW, CreateProcessWithTokenW, or WinExec. (Citation: Elastic Process Injection July 2017)

AppInit DLLs
type: Class
subclass of: Event Triggered Execution
subclass of: Restriction
  on property: invokes
  some values from: Create Process
subclass of: Restriction
  on property: loads
  some values from: Shared Library File
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database Record
type: NamedIndividual
invokes: Create Process
loads: Shared Library File
modifies: System Configuration Database Record
attack-id: T1546.010
definition: Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by AppInit DLLs loaded into processes. Dynamic-link libraries (DLLs) that are specified in the AppInit_DLLs value in the Registry keys HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Windows or HKEY_LOCAL_MACHINE\Software\Wow6432Node\Microsoft\Windows NT\CurrentVersion\Windows are loaded by user32.dll into every process that loads user32.dll. In practice this is nearly every program, since user32.dll is a very common library. (Citation: Elastic Process Injection July 2017)

Application Shimming
type: Class
subclass of: Event Triggered Execution
subclass of: Restriction
  on property: creates
  some values from: Shim
subclass of: Restriction
  on property: modifies
  some values from: Shim Database
type: NamedIndividual
creates: Shim
modifies: Shim Database
attack-id: T1546.011
definition: Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by application shims. The Microsoft Windows Application Compatibility Infrastructure/Framework (Application Shim) was created to allow for backward compatibility of software as the operating system codebase changes over time. For example, the application shimming feature allows developers to apply fixes to applications (without rewriting code) that were created for Windows XP so that it will work with Windows 10. (Citation: Elastic Process Injection July 2017)

Image File Execution Options Injection
type: Class
subclass of: Event Triggered Execution
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database
type: NamedIndividual
modifies: System Configuration Database
attack-id: T1546.012
definition: Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by Image File Execution Options (IFEO) debuggers. IFEOs enable a developer to attach a debugger to an application. When a process is created, a debugger present in an application’s IFEO will be prepended to the application’s name, effectively launching the new process under the debugger (e.g., C:\dbg\ntsd.exe -g notepad.exe). (Citation: Microsoft Dev Blog IFEO Mar 2010)

PowerShell Profile
type: Class
subclass of: Event Triggered Execution
subclass of: Restriction
  on property: modifies
  some values from: PowerShell Profile Script
type: NamedIndividual
modifies: PowerShell Profile Script
attack-id: T1546.013
definition: Adversaries may gain persistence and elevate privileges by executing malicious content triggered by PowerShell profiles. A PowerShell profile (profile.ps1) is a script that runs when [PowerShell](https://attack.mitre.org/techniques/T1059/001) starts and can be used as a logon script to customize user environments.

Emond
type: Class
subclass of: Event Triggered Execution
subclass of: Restriction
  on property: may-create
  some values from: Property List File
subclass of: Restriction
  on property: may-modify
  some values from: Property List File
subclass of: Restriction
  on property: modifies
  some values from: Configuration Resource
type: NamedIndividual
may-create: Property List File
may-modify: Property List File
modifies: Configuration Resource
attack-id: T1546.014
definition: Adversaries may gain persistence and elevate privileges by executing malicious content triggered by the Event Monitor Daemon (emond). Emond is a [Launch Daemon](https://attack.mitre.org/techniques/T1543/004) that accepts events from various services, runs them through a simple rules engine, and takes action. The emond binary at /sbin/emond will load any rules from the /etc/emond.d/rules/ directory and take action once an explicitly defined event takes place.

Component Object Model Hijacking
type: Class
subclass of: Event Triggered Execution
subclass of: Restriction
  on property: loads
  some values from: Executable Binary
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database
type: NamedIndividual
loads: Executable Binary
modifies: System Configuration Database
attack-id: T1546.015
definition: Adversaries may establish persistence by executing malicious content triggered by hijacked references to Component Object Model (COM) objects. COM is a system within Windows to enable interaction between software components through the operating system.(Citation: Microsoft Component Object Model) References to various COM objects are stored in the Registry.

Installer Packages
type: Class
subclass of: Event Triggered Execution
attack-id: T1546.016
definition: Adversaries may establish persistence and elevate privileges by using an installer to trigger the execution of malicious content. Installer packages are OS specific and contain the resources an operating system needs to install applications on a system. Installer packages can include scripts that run prior to installation as well as after installation is complete. Installer scripts may inherit elevated permissions when executed. Developers often use these scripts to prepare the environment for installation, check requirements, download dependencies, and remove files after installation.(Citation: Installer Package Scripting Rich Trouton)

Udev Rules
type: Class
subclass of: Event Triggered Execution
attack-id: T1546.017
definition: Adversaries may maintain persistence through executing malicious content triggered using udev rules. Udev is the Linux kernel device manager that dynamically manages device nodes, handles access to pseudo-device files in the `/dev` directory, and responds to hardware events, such as when external devices like hard drives or keyboards are plugged in or removed. Udev uses rule files with `match keys` to specify the conditions a hardware event must meet and `action keys` to define the actions that should follow. Root permissions are required to create, modify, or delete rule files located in `/etc/udev/rules.d/`, `/run/udev/rules.d/`, `/usr/lib/udev/rules.d/`, `/usr/local/lib/udev/rules.d/`, and `/lib/udev/rules.d/`. Rule priority is determined by both directory and by the digit prefix in the rule filename.(Citation: Ignacio Udev research 2024)(Citation: Elastic Linux Persistence 2024)

Boot or Logon Autostart Execution
type: Class
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1547
definition: Adversaries may configure system settings to automatically execute a program during system boot or logon to maintain persistence or gain higher-level privileges on compromised systems. Operating systems may have mechanisms for automatically running a program on system boot or account logon.(Citation: Microsoft Run Key)(Citation: MSDN Authentication Packages)(Citation: Microsoft TimeProvider)(Citation: Cylance Reg Persistence Sept 2013)(Citation: Linux Kernel Programming) These mechanisms may include automatically executing programs that are placed in specially designated directories or are referenced by repositories that store configuration information, such as the Windows Registry. An adversary may achieve the same goal by modifying or extending features of the kernel.

Registry Run Keys / Startup Folder
type: Class
subclass of: Boot or Logon Autostart Execution
subclass of: Restriction
  on property: may-modify
  some values from: System Configuration Init Database Record
subclass of: Restriction
  on property: may-modify
  some values from: User Startup Script File
type: NamedIndividual
may-modify: System Configuration Init Database Record
may-modify: User Startup Script File
attack-id: T1547.001
definition: Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key. Adding an entry to the "run keys" in the Registry or startup folder will cause the program referenced to be executed when a user logs in.(Citation: Microsoft Run Key) These programs will be executed under the context of the user and will have the account's associated permissions level.

Authentication Package
type: Class
subclass of: Boot or Logon Autostart Execution
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database Record
type: NamedIndividual
modifies: System Configuration Database Record
attack-id: T1547.002
definition: Adversaries may abuse authentication packages to execute DLLs when the system boots. Windows authentication package DLLs are loaded by the Local Security Authority (LSA) process at system start. They provide support for multiple logon processes and multiple security protocols to the operating system.(Citation: MSDN Authentication Packages)

Time Providers
type: Class
subclass of: Boot or Logon Autostart Execution
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database Record
type: NamedIndividual
modifies: System Configuration Database Record
attack-id: T1547.003
definition: Adversaries may abuse time providers to execute DLLs when the system boots. The Windows Time service (W32Time) enables time synchronization across and within domains.(Citation: Microsoft W32Time Feb 2018) W32Time time providers are responsible for retrieving time stamps from hardware/network resources and outputting these values to other network clients.(Citation: Microsoft TimeProvider)

Winlogon Helper DLL
type: Class
subclass of: Boot or Logon Autostart Execution
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database Record
type: NamedIndividual
modifies: System Configuration Database Record
attack-id: T1547.004
definition: Adversaries may abuse features of Winlogon to execute DLLs and/or executables when a user logs in. Winlogon.exe is a Windows component responsible for actions at logon/logoff as well as the secure attention sequence (SAS) triggered by Ctrl-Alt-Delete. Registry entries in HKLM\Software[\\Wow6432Node\\]\Microsoft\Windows NT\CurrentVersion\Winlogon\ and HKCU\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\ are used to manage additional helper programs and functionalities that support Winlogon.(Citation: Cylance Reg Persistence Sept 2013)

Security Support Provider
type: Class
subclass of: Boot or Logon Autostart Execution
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database Record
type: NamedIndividual
modifies: System Configuration Database Record
attack-id: T1547.005
definition: Adversaries may abuse security support providers (SSPs) to execute DLLs when the system boots. Windows SSP DLLs are loaded into the Local Security Authority (LSA) process at system start. Once loaded into the LSA, SSP DLLs have access to encrypted and plaintext passwords that are stored in Windows, such as any logged-on user's Domain password or smart card PINs.

Kernel Modules and Extensions
type: Class
subclass of: Boot or Logon Autostart Execution
subclass of: Restriction
  on property: modifies
  some values from: Kernel Module
type: NamedIndividual
modifies: Kernel Module
attack-id: T1547.006
definition: Adversaries may modify the kernel to automatically execute programs on system boot. Loadable Kernel Modules (LKMs) are pieces of code that can be loaded and unloaded into the kernel upon demand. They extend the functionality of the kernel without the need to reboot the system. For example, one type of module is the device driver, which allows the kernel to access hardware connected to the system.(Citation: Linux Kernel Programming)

Re-opened Applications
type: Class
subclass of: Boot or Logon Autostart Execution
subclass of: Restriction
  on property: modifies
  some values from: Application Configuration File
type: NamedIndividual
modifies: Application Configuration File
attack-id: T1547.007
definition: Adversaries may modify plist files to automatically run an application when a user logs in. When a user logs out or restarts via the macOS Graphical User Interface (GUI), a prompt is provided to the user with a checkbox to "Reopen windows when logging back in".(Citation: Re-Open windows on Mac) When selected, all applications currently open are added to a property list file named com.apple.loginwindow.[UUID].plist within the ~/Library/Preferences/ByHost directory.(Citation: Methods of Mac Malware Persistence)(Citation: Wardle Persistence Chapter) Applications listed in this file are automatically reopened upon the user’s next logon.

LSASS Driver
type: Class
subclass of: Boot or Logon Autostart Execution
subclass of: Restriction
  on property: may-create
  some values from: Shared Library File
subclass of: Restriction
  on property: modifies
  some values from: System Service Software
type: NamedIndividual
may-create: Shared Library File
modifies: System Service Software
attack-id: T1547.008
definition: Adversaries may modify or add LSASS drivers to obtain persistence on compromised systems. The Windows security subsystem is a set of components that manage and enforce the security policy for a computer or domain. The Local Security Authority (LSA) is the main component responsible for local security policy and user authentication. The LSA includes multiple dynamic link libraries (DLLs) associated with various other security functions, all of which run in the context of the LSA Subsystem Service (LSASS) lsass.exe process.(Citation: Microsoft Security Subsystem)

Shortcut Modification
type: Class
subclass of: Boot or Logon Autostart Execution
subclass of: Restriction
  on property: may-modify
  some values from: Symbolic Link
subclass of: Restriction
  on property: may-modify
  some values from: User Startup Script File
type: NamedIndividual
may-modify: Symbolic Link
may-modify: User Startup Script File
attack-id: T1547.009
definition: Adversaries may create or modify shortcuts that can execute a program during system boot or user login. Shortcuts or symbolic links are used to reference other files or programs that will be opened or executed when the shortcut is clicked or executed by a system startup process.

Port Monitors
type: Class
subclass of: Boot or Logon Autostart Execution
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database Record
type: NamedIndividual
modifies: System Configuration Database Record
attack-id: T1547.010
definition: Adversaries may use port monitors to run an adversary supplied DLL during system boot for persistence or privilege escalation. A port monitor can be set through the AddMonitor API call to set a DLL to be loaded at startup.(Citation: AddMonitor) This DLL can be located in C:\Windows\System32 and will be loaded and run by the print spooler service, `spoolsv.exe`, under SYSTEM level permissions on boot.(Citation: Bloxham)

Plist Modification
type: Class
subclass of: Boot or Logon Autostart Execution
subclass of: Restriction
  on property: modifies
  some values from: Application Configuration File
type: NamedIndividual
modifies: Application Configuration File
attack-id: T1547.011
definition: Adversaries can modify property list files (plist files) to execute their code as part of establishing persistence. Plist files are used by macOS applications to store properties and configuration settings for applications and services. Applications use information plist files, Info.plist, to tell the operating system how to handle the application at runtime using structured metadata in the form of keys and values. Plist files are formatted in XML and based on Apple's Core Foundation DTD and can be saved in text or binary format.(Citation: fileinfo plist file description)
comment: This technique has been revoked by T1647
deprecated: true

Print Processors
type: Class
subclass of: Boot or Logon Autostart Execution
attack-id: T1547.012
definition: Adversaries may abuse print processors to run malicious DLLs during system boot for persistence and/or privilege escalation. Print processors are DLLs that are loaded by the print spooler service, `spoolsv.exe`, during boot.(Citation: Microsoft Intro Print Processors)

XDG Autostart Entries
type: Class
subclass of: Boot or Logon Autostart Execution
attack-id: T1547.013
definition: Adversaries may add or modify XDG Autostart Entries to execute malicious programs or commands when a user’s desktop environment is loaded at login. XDG Autostart entries are available for any XDG-compliant Linux system. XDG Autostart entries use Desktop Entry files (`.desktop`) to configure the user’s desktop environment upon user login. These configuration files determine what applications launch upon user login, define associated applications to open specific file types, and define applications used to open removable media.(Citation: Free Desktop Application Autostart Feb 2006)(Citation: Free Desktop Entry Keys)

Active Setup
type: Class
subclass of: Boot or Logon Autostart Execution
attack-id: T1547.014
definition: Adversaries may achieve persistence by adding a Registry key to the Active Setup of the local machine. Active Setup is a Windows mechanism that is used to execute programs when a user logs in. The value stored in the Registry key will be executed after a user logs into the computer.(Citation: Klein Active Setup 2010) These programs will be executed under the context of the user and will have the account's associated permissions level.

Login Items
type: Class
subclass of: Boot or Logon Autostart Execution
subclass of: Restriction
  on property: modifies
  some values from: User Logon Init Resource
type: NamedIndividual
modifies: User Logon Init Resource
attack-id: T1547.015
definition: Adversaries may add login items to execute upon user login to gain persistence or escalate privileges. Login items are applications, documents, folders, or server connections that are automatically launched when a user logs in.(Citation: Open Login Items Apple) Login items can be added via a shared file list or Service Management Framework.(Citation: Adding Login Items) Shared file list login items can be set using scripting languages such as [AppleScript](https://attack.mitre.org/techniques/T1059/002), whereas the Service Management Framework uses the API call SMLoginItemSetEnabled.

Abuse Elevation Control Mechanism
type: Class
subclass of: Defense Evasion Technique
subclass of: Privilege Escalation Technique
attack-id: T1548
definition: Adversaries may circumvent mechanisms designed to control elevate privileges to gain higher-level permissions. Most modern systems contain native elevation control mechanisms that are intended to limit privileges that a user can perform on a machine. Authorization has to be granted to specific users in order to perform tasks that can be considered of higher risk.(Citation: TechNet How UAC Works)(Citation: sudo man page 2018) An adversary can perform several methods to take advantage of built-in control mechanisms in order to escalate privileges on a system.(Citation: OSX Keydnap malware)(Citation: Fortinet Fareit)

Setuid and Setgid
type: Class
subclass of: Abuse Elevation Control Mechanism
subclass of: Restriction
  on property: modifies
  some values from: Access Control Configuration
type: NamedIndividual
modifies: Access Control Configuration
attack-id: T1548.001
definition: An adversary may abuse configurations where an application has the setuid or setgid bits set in order to get code running in a different (and possibly more privileged) user’s context. On Linux or macOS, when the setuid or setgid bits are set for an application binary, the application will run with the privileges of the owning user or group respectively.(Citation: setuid man page) Normally an application is run in the current user’s context, regardless of which user or group owns the application. However, there are instances where programs need to be executed in an elevated context to function properly, but the user running them may not have the specific required privileges.

Bypass User Account Control
type: Class
subclass of: Abuse Elevation Control Mechanism
subclass of: Restriction
  on property: executes
  some values from: Executable File
subclass of: Restriction
  on property: invokes
  some values from: Create Process
subclass of: Restriction
  on property: may-modify
  some values from: System Configuration Database Record
type: NamedIndividual
executes: Executable File
invokes: Create Process
may-modify: System Configuration Database Record
attack-id: T1548.002
definition: Adversaries may bypass UAC mechanisms to elevate process privileges on system. Windows User Account Control (UAC) allows a program to elevate its privileges (tracked as integrity levels ranging from low to high) to perform a task under administrator-level permissions, possibly by prompting the user for confirmation. The impact to the user ranges from denying the operation under high enforcement to allowing the user to perform the action if they are in the local administrators group and click through the prompt or allowing them to enter an administrator password to complete the action.(Citation: TechNet How UAC Works)

Sudo and Sudo Caching
type: Class
subclass of: Abuse Elevation Control Mechanism
subclass of: Restriction
  on property: may-modify
  some values from: Event Log
subclass of: Restriction
  on property: modifies
  some values from: Operating System Configuration File
type: NamedIndividual
may-modify: Event Log
modifies: Operating System Configuration File
attack-id: T1548.003
definition: Adversaries may perform sudo caching and/or use the sudoers file to elevate privileges. Adversaries may do this to execute commands as other users or spawn processes with higher privileges.

Elevated Execution with Prompt
type: Class
subclass of: Abuse Elevation Control Mechanism
subclass of: Restriction
  on property: creates
  some values from: System Configuration Database
subclass of: Restriction
  on property: invokes
  some values from: System Call
type: NamedIndividual
creates: System Configuration Database
invokes: System Call
attack-id: T1548.004
definition: Adversaries may leverage the AuthorizationExecuteWithPrivileges API to escalate privileges by prompting the user for credentials.(Citation: AppleDocs AuthorizationExecuteWithPrivileges) The purpose of this API is to give application developers an easy way to perform operations with root privileges, such as for application installation or updating. This API does not validate that the program requesting root privileges comes from a reputable source or has been maliciously modified.

Temporary Elevated Cloud Access
type: Class
subclass of: Abuse Elevation Control Mechanism
attack-id: T1548.005
definition: Adversaries may abuse permission configurations that allow them to gain temporarily elevated access to cloud resources. Many cloud environments allow administrators to grant user or service accounts permission to request just-in-time access to roles, impersonate other accounts, pass roles onto resources and services, or otherwise gain short-term access to a set of privileges that may be distinct from their own.

TCC Manipulation
type: Class
subclass of: Abuse Elevation Control Mechanism
attack-id: T1548.006
definition: Adversaries can manipulate or abuse the Transparency, Consent, & Control (TCC) service or database to execute malicious applications with elevated permissions. TCC is a Privacy & Security macOS control mechanism used to determine if the running process has permission to access the data or services protected by TCC, such as screen sharing, camera, microphone, or Full Disk Access (FDA).

Use Alternate Authentication Material
type: Class
subclass of: Defense Evasion Technique
subclass of: Lateral Movement Technique
subclass of: Restriction
  on property: accesses
  some values from: Authentication Service
type: NamedIndividual
accesses: Authentication Service
attack-id: T1550
definition: Adversaries may use alternate authentication material, such as password hashes, Kerberos tickets, and application access tokens, in order to move laterally within an environment and bypass normal system access controls.

Application Access Token
type: Class
subclass of: Use Alternate Authentication Material
subclass of: Restriction
  on property: may-produce
  some values from: Network Traffic
subclass of: Restriction
  on property: uses
  some values from: Access Token
type: NamedIndividual
may-produce: Network Traffic
uses: Access Token
attack-id: T1550.001
definition: Adversaries may use stolen application access tokens to bypass the typical authentication process and access restricted accounts, information, or services on remote systems. These tokens are typically stolen from users or services and used in lieu of login credentials.

Pass the Hash
type: Class
subclass of: Use Alternate Authentication Material
subclass of: Restriction
  on property: creates
  some values from: Authentication
type: NamedIndividual
creates: Authentication
attack-id: T1550.002
definition: Adversaries may “pass the hash” using stolen password hashes to move laterally within an environment, bypassing normal system access controls. Pass the hash (PtH) is a method of authenticating as a user without having access to the user's cleartext password. This method bypasses standard authentication steps that require a cleartext password, moving directly into the portion of the authentication that uses the password hash.

Pass the Ticket
type: Class
subclass of: Use Alternate Authentication Material
subclass of: Restriction
  on property: creates
  some values from: Authentication
type: NamedIndividual
creates: Authentication
attack-id: T1550.003
definition: Adversaries may “pass the ticket” using stolen Kerberos tickets to move laterally within an environment, bypassing normal system access controls. Pass the ticket (PtT) is a method of authenticating to a system using Kerberos tickets without having access to an account's password. Kerberos authentication can be used as the first step to lateral movement to a remote system.

Web Session Cookie
type: Class
subclass of: Use Alternate Authentication Material
subclass of: Restriction
  on property: adds
  some values from: Session Cookie
subclass of: Restriction
  on property: produces
  some values from: Web Network Traffic
type: NamedIndividual
adds: Session Cookie
produces: Web Network Traffic
attack-id: T1550.004
definition: Adversaries can use stolen session cookies to authenticate to web applications and services. This technique bypasses some multi-factor authentication protocols since the session is already authenticated.(Citation: Pass The Cookie)

Unsecured Credentials
type: Class
subclass of: Credential Access Technique
subclass of: Restriction
  on property: accesses
  some values from: Credential
type: NamedIndividual
accesses: Credential
attack-id: T1552
definition: Adversaries may search compromised systems to find and obtain insecurely stored credentials. These credentials can be stored and/or misplaced in many locations on a system, including plaintext files (e.g. [Bash History](https://attack.mitre.org/techniques/T1552/003)), operating system or application-specific repositories (e.g. [Credentials in Registry](https://attack.mitre.org/techniques/T1552/002)), or other specialized files/artifacts (e.g. [Private Keys](https://attack.mitre.org/techniques/T1552/004)).(Citation: Brining MimiKatz to Unix)

Credentials In Files
type: Class
subclass of: Unsecured Credentials
subclass of: Restriction
  on property: accesses
  some values from: File
type: NamedIndividual
accesses: File
attack-id: T1552.001
definition: Adversaries may search local file systems and remote file shares for files containing insecurely stored credentials. These can be files created by users to store their own credentials, shared credential stores for a group of individuals, configuration files containing passwords for a system or service, or source code/binary files containing embedded passwords.

Credentials in Registry
type: Class
subclass of: Unsecured Credentials
subclass of: Restriction
  on property: accesses
  some values from: System Configuration Database
type: NamedIndividual
accesses: System Configuration Database
attack-id: T1552.002
definition: Adversaries may search the Registry on compromised systems for insecurely stored credentials. The Windows Registry stores configuration information that can be used by the system or other programs. Adversaries may query the Registry looking for credentials and passwords that have been stored for use by other programs or services. Sometimes these credentials are used for automatic logons.

Bash History
type: Class
subclass of: Unsecured Credentials
subclass of: Restriction
  on property: accesses
  some values from: Command History Log File
type: NamedIndividual
accesses: Command History Log File
attack-id: T1552.003
definition: Adversaries may search the bash command history on compromised systems for insecurely stored credentials. Bash keeps track of the commands users type on the command-line with the "history" utility. Once a user logs out, the history is flushed to the user’s .bash_history file. For each user, this file resides at the same location: ~/.bash_history. Typically, this file keeps track of the user’s last 500 commands. Users often type usernames and passwords on the command-line as parameters to programs, which then get saved to this file when they log out. Adversaries can abuse this by looking through the file for potential credentials. (Citation: External to DA, the OS X Way)

Private Keys
type: Class
subclass of: Unsecured Credentials
subclass of: Restriction
  on property: accesses
  some values from: Private Key
type: NamedIndividual
accesses: Private Key
attack-id: T1552.004
definition: Adversaries may search for private key certificate files on compromised systems for insecurely stored credentials. Private cryptographic keys and certificates are used for authentication, encryption/decryption, and digital signatures.(Citation: Wikipedia Public Key Crypto) Common key and certificate file extensions include: .key, .pgp, .gpg, .ppk., .p12, .pem, .pfx, .cer, .p7b, .asc.

Cloud Instance Metadata API
type: Class
subclass of: Unsecured Credentials
subclass of: Restriction
  on property: accesses
  some values from: Cloud Instance Metadata
type: NamedIndividual
accesses: Cloud Instance Metadata
attack-id: T1552.005
definition: Adversaries may attempt to access the Cloud Instance Metadata API to collect credentials and other sensitive data.

Group Policy Preferences
type: Class
subclass of: Unsecured Credentials
subclass of: Restriction
  on property: accesses
  some values from: Group Policy
type: NamedIndividual
accesses: Group Policy
attack-id: T1552.006
definition: Adversaries may attempt to find unsecured credentials in Group Policy Preferences (GPP). GPP are tools that allow administrators to create domain policies with embedded credentials. These policies allow administrators to set local accounts.(Citation: Microsoft GPP 2016)

Container API
type: Class
subclass of: Unsecured Credentials
attack-id: T1552.007
definition: Adversaries may gather credentials via APIs within a containers environment. APIs in these environments, such as the Docker API and Kubernetes APIs, allow a user to remotely manage their container resources and cluster components.(Citation: Docker API)(Citation: Kubernetes API)

Chat Messages
type: Class
subclass of: Unsecured Credentials
attack-id: T1552.008
definition: Adversaries may directly collect unsecured credentials stored or passed through user communication services. Credentials may be sent and stored in user chat communication applications such as email, chat services like Slack or Teams, collaboration tools like Jira or Trello, and any other services that support user communication. Users may share various forms of credentials (such as usernames and passwords, API keys, or authentication tokens) on private or public corporate internal communications channels.

Subvert Trust Controls
type: Class
subclass of: Defense Evasion Technique
attack-id: T1553
definition: Adversaries may undermine security controls that will either warn users of untrusted activity or prevent execution of untrusted programs. Operating systems and security products may contain mechanisms to identify programs or websites as possessing some level of trust. Examples of such features would include a program being allowed to run because it is signed by a valid code signing certificate, a program prompting the user with a warning because it has an attribute set from being downloaded from the Internet, or getting an indication that you are about to connect to an untrusted site.

Gatekeeper Bypass
type: Class
subclass of: Subvert Trust Controls
subclass of: Restriction
  on property: modifies
  some values from: File System Metadata
type: NamedIndividual
modifies: File System Metadata
attack-id: T1553.001
definition: Adversaries may modify file attributes and subvert Gatekeeper functionality to evade user prompts and execute untrusted programs. Gatekeeper is a set of technologies that act as layer of Apple’s security model to ensure only trusted applications are executed on a host. Gatekeeper was built on top of File Quarantine in Snow Leopard (10.6, 2009) and has grown to include Code Signing, security policy compliance, Notarization, and more. Gatekeeper also treats applications running for the first time differently than reopened applications.(Citation: TheEclecticLightCompany Quarantine and the flag)(Citation: TheEclecticLightCompany apple notarization )

Code Signing
type: Class
subclass of: Subvert Trust Controls
subclass of: Restriction
  on property: enables
  some values from: Defense Evasion
type: NamedIndividual
enables: Defense Evasion
attack-id: T1553.002
definition: Adversaries may create, acquire, or steal code signing materials to sign their malware or tools. Code signing provides a level of authenticity on a binary from the developer and a guarantee that the binary has not been tampered with. (Citation: Wikipedia Code Signing) The certificates used during an operation may be created, acquired, or stolen by the adversary. (Citation: Securelist Digital Certificates) (Citation: Symantec Digital Certificates) Unlike [Invalid Code Signature](https://attack.mitre.org/techniques/T1036/001), this activity will result in a valid signature.

SIP and Trust Provider Hijacking
type: Class
subclass of: Subvert Trust Controls
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database Record
type: NamedIndividual
modifies: System Configuration Database Record
attack-id: T1553.003
definition: Adversaries may tamper with SIP and trust provider components to mislead the operating system and application control tools when conducting signature validation checks. In user mode, Windows Authenticode (Citation: Microsoft Authenticode) digital signatures are used to verify a file's origin and integrity, variables that may be used to establish trust in signed code (ex: a driver with a valid Microsoft signature may be handled as safe). The signature validation process is handled via the WinVerifyTrust application programming interface (API) function, (Citation: Microsoft WinVerifyTrust) which accepts an inquiry and coordinates with the appropriate trust provider, which is responsible for validating parameters of a signature. (Citation: SpectorOps Subverting Trust Sept 2017)

Install Root Certificate
type: Class
subclass of: Subvert Trust Controls
subclass of: Restriction
  on property: modifies
  some values from: Certificate Trust Store
type: NamedIndividual
modifies: Certificate Trust Store
attack-id: T1553.004
definition: Adversaries may install a root certificate on a compromised system to avoid warnings when connecting to adversary controlled web servers. Root certificates are used in public key cryptography to identify a root certificate authority (CA). When a root certificate is installed, the system or application will trust certificates in the root's chain of trust that have been signed by the root certificate.(Citation: Wikipedia Root Certificate) Certificates are commonly used for establishing secure TLS/SSL communications within a web browser. When a user attempts to browse a website that presents a certificate that is not trusted an error message will be displayed to warn the user of the security risk. Depending on the security settings, the browser may not allow the user to establish a connection to the website.

Mark-of-the-Web Bypass
type: Class
subclass of: Subvert Trust Controls
attack-id: T1553.005
definition: Adversaries may abuse specific file formats to subvert Mark-of-the-Web (MOTW) controls. In Windows, when files are downloaded from the Internet, they are tagged with a hidden NTFS Alternate Data Stream (ADS) named Zone.Identifier with a specific value known as the MOTW.(Citation: Microsoft Zone.Identifier 2020) Files that are tagged with MOTW are protected and cannot perform certain actions. For example, starting in MS Office 10, if a MS Office file has the MOTW, it will open in Protected View. Executables tagged with the MOTW will be processed by Windows Defender SmartScreen that compares files with an allowlist of well-known executables. If the file is not known/trusted, SmartScreen will prevent the execution and warn the user not to run it.(Citation: Beek Use of VHD Dec 2020)(Citation: Outflank MotW 2020)(Citation: Intezer Russian APT Dec 2020)

Code Signing Policy Modification
type: Class
subclass of: Subvert Trust Controls
attack-id: T1553.006
definition: Adversaries may modify code signing policies to enable execution of unsigned or self-signed code. Code signing provides a level of authenticity on a program from a developer and a guarantee that the program has not been tampered with. Security controls can include enforcement mechanisms to ensure that only valid, signed code can be run on an operating system.

Compromise Host Software Binary
type: Class
subclass of: Persistence Technique
subclass of: Restriction
  on property: modifies
  some values from: Client Application
type: NamedIndividual
modifies: Client Application
attack-id: T1554
definition: Adversaries may modify host software binaries to establish persistent access to systems. Software binaries/executables provide a wide range of system commands or services, programs, and libraries. Common software binaries are SSH clients, FTP clients, email clients, web browsers, and many other user or server applications.

Credentials from Password Stores
type: Class
subclass of: Credential Access Technique
subclass of: Restriction
  on property: accesses
  some values from: Password Store
subclass of: Restriction
  on property: may-access
  some values from: Database File
type: NamedIndividual
accesses: Password Store
may-access: Database File
attack-id: T1555
definition: Adversaries may search for common password storage locations to obtain user credentials.(Citation: F-Secure The Dukes) Passwords are stored in several places on a system, depending on the operating system or application holding the credentials. There are also specific applications and services that store passwords to make them easier for users to manage and maintain, such as password managers and cloud secrets vaults. Once credentials are obtained, they can be used to perform lateral movement and access restricted information.

Keychain
type: Class
subclass of: Credentials from Password Stores
subclass of: Restriction
  on property: accesses
  some values from: MacOS Keychain
type: NamedIndividual
accesses: MacOS Keychain
attack-id: T1555.001
definition: Adversaries may acquire credentials from Keychain. Keychain (or Keychain Services) is the macOS credential management system that stores account names, passwords, private keys, certificates, sensitive application data, payment data, and secure notes. There are three types of Keychains: Login Keychain, System Keychain, and Local Items (iCloud) Keychain. The default Keychain is the Login Keychain, which stores user passwords and information. The System Keychain stores items accessed by the operating system, such as items shared among users on a host. The Local Items (iCloud) Keychain is used for items synced with Apple’s iCloud service.

Securityd Memory
type: Class
subclass of: Credentials from Password Stores
subclass of: Restriction
  on property: accesses
  some values from: In-memory Password Store
type: NamedIndividual
accesses: In-memory Password Store
attack-id: T1555.002
definition: An adversary with root access may gather credentials by reading `securityd`’s memory. `securityd` is a service/daemon responsible for implementing security protocols such as encryption and authorization.(Citation: Apple Dev SecurityD) A privileged adversary may be able to scan through `securityd`'s memory to find the correct sequence of keys to decrypt the user’s logon keychain. This may provide the adversary with various plaintext passwords, such as those for users, WiFi, mail, browsers, certificates, secure notes, etc.(Citation: OS X Keychain)(Citation: OSX Keydnap malware)

Credentials from Web Browsers
type: Class
subclass of: Credentials from Password Stores
subclass of: Restriction
  on property: accesses
  some values from: Database File
subclass of: Restriction
  on property: may-access
  some values from: In-memory Password Store
subclass of: Restriction
  on property: may-invoke
  some values from: Read File
type: NamedIndividual
accesses: Database File
may-access: In-memory Password Store
may-invoke: Read File
attack-id: T1555.003
definition: Adversaries may acquire credentials from web browsers by reading files specific to the target browser.(Citation: Talos Olympic Destroyer 2018) Web browsers commonly save credentials such as website usernames and passwords so that they do not need to be entered manually in the future. Web browsers typically store the credentials in an encrypted format within a credential store; however, methods exist to extract plaintext credentials from web browsers.

Windows Credential Manager
type: Class
subclass of: Credentials from Password Stores
attack-id: T1555.004
definition: Adversaries may acquire credentials from the Windows Credential Manager. The Credential Manager stores credentials for signing into websites, applications, and/or devices that request authentication through NTLM or Kerberos in Credential Lockers (previously known as Windows Vaults).(Citation: Microsoft Credential Manager store)(Citation: Microsoft Credential Locker)

Password Managers
type: Class
subclass of: Credentials from Password Stores
attack-id: T1555.005
definition: Adversaries may acquire user credentials from third-party password managers.(Citation: ise Password Manager February 2019) Password managers are applications designed to store user credentials, normally in an encrypted database. Credentials are typically accessible after a user provides a master password that unlocks the database. After the database is unlocked, these credentials may be copied to memory. These databases can be stored as files on disk.(Citation: ise Password Manager February 2019)

Cloud Secrets Management Stores
type: Class
subclass of: Credentials from Password Stores
attack-id: T1555.006
definition: Adversaries may acquire credentials from cloud-native secret management solutions such as AWS Secrets Manager, GCP Secret Manager, Azure Key Vault, and Terraform Vault.

Modify Authentication Process
type: Class
subclass of: Credential Access Technique
subclass of: Defense Evasion Technique
subclass of: Restriction
  on property: modifies
  some values from: Authentication Service
type: NamedIndividual
modifies: Authentication Service
attack-id: T1556
definition: Adversaries may modify authentication mechanisms and processes to access user credentials or enable otherwise unwarranted access to accounts. The authentication process is handled by mechanisms, such as the Local Security Authentication Server (LSASS) process and the Security Accounts Manager (SAM) on Windows, pluggable authentication modules (PAM) on Unix-based systems, and authorization plugins on MacOS systems, responsible for gathering, storing, and validating credentials. By modifying an authentication process, an adversary may be able to authenticate to a service or system without using [Valid Accounts](https://attack.mitre.org/techniques/T1078).

Domain Controller Authentication
type: Class
subclass of: Modify Authentication Process
attack-id: T1556.001
definition: Adversaries may patch the authentication process on a domain controller to bypass the typical authentication mechanisms and enable access to accounts.

Password Filter DLL
type: Class
subclass of: Modify Authentication Process
subclass of: Restriction
  on property: creates
  some values from: Shared Library File
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database Record
type: NamedIndividual
creates: Shared Library File
modifies: System Configuration Database Record
attack-id: T1556.002
definition: Adversaries may register malicious password filter dynamic link libraries (DLLs) into the authentication process to acquire user credentials as they are validated.

Pluggable Authentication Modules
type: Class
subclass of: Modify Authentication Process
subclass of: Restriction
  on property: may-modify
  some values from: Operating System Configuration File
subclass of: Restriction
  on property: may-modify
  some values from: Operating System Shared Library File
type: NamedIndividual
may-modify: Operating System Configuration File
may-modify: Operating System Shared Library File
attack-id: T1556.003
definition: Adversaries may modify pluggable authentication modules (PAM) to access user credentials or enable otherwise unwarranted access to accounts. PAM is a modular system of configuration files, libraries, and executable files which guide authentication for many services. The most common authentication module is pam_unix.so, which retrieves, sets, and verifies account authentication information in /etc/passwd and /etc/shadow.(Citation: Apple PAM)(Citation: Man Pam_Unix)(Citation: Red Hat PAM)

Network Device Authentication
type: Class
subclass of: Modify Authentication Process
attack-id: T1556.004
definition: Adversaries may use [Patch System Image](https://attack.mitre.org/techniques/T1601/001) to hard code a password in the operating system, thus bypassing of native authentication mechanisms for local accounts on network devices.

Reversible Encryption
type: Class
subclass of: Modify Authentication Process
attack-id: T1556.005
definition: An adversary may abuse Active Directory authentication encryption properties to gain access to credentials on Windows systems. The AllowReversiblePasswordEncryption property specifies whether reversible password encryption for an account is enabled or disabled. By default this property is disabled (instead storing user credentials as the output of one-way hashing functions) and should not be enabled unless legacy or other software require it.(Citation: store_pwd_rev_enc)

Multi-Factor Authentication
type: Class
subclass of: Modify Authentication Process
attack-id: T1556.006
definition: Adversaries may disable or modify multi-factor authentication (MFA) mechanisms to enable persistent access to compromised accounts.

Hybrid Identity
type: Class
subclass of: Modify Authentication Process
attack-id: T1556.007
definition: Adversaries may patch, modify, or otherwise backdoor cloud authentication processes that are tied to on-premises user identities in order to bypass typical authentication mechanisms, access credentials, and enable persistent access to accounts.

Network Provider DLL
type: Class
subclass of: Modify Authentication Process
attack-id: T1556.008
definition: Adversaries may register malicious network provider dynamic link libraries (DLLs) to capture cleartext user credentials during the authentication process. Network provider DLLs allow Windows to interface with specific network protocols and can also support add-on credential management functions.(Citation: Network Provider API) During the logon process, Winlogon (the interactive logon module) sends credentials to the local `mpnotify.exe` process via RPC. The `mpnotify.exe` process then shares the credentials in cleartext with registered credential managers when notifying that a logon event is happening.(Citation: NPPSPY - Huntress)(Citation: NPPSPY Video)(Citation: NPLogonNotify)

Conditional Access Policies
type: Class
subclass of: Modify Authentication Process
attack-id: T1556.009
definition: Adversaries may disable or modify conditional access policies to enable persistent access to compromised accounts. Conditional access policies are additional verifications used by identity providers and identity and access management systems to determine whether a user should be granted access to a resource.

Adversary-in-the-Middle
type: Class
subclass of: Collection Technique
subclass of: Credential Access Technique
subclass of: Restriction
  on property: produces
  some values from: Network Traffic
type: NamedIndividual
produces: Network Traffic
attack-id: T1557
definition: Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.mitre.org/techniques/T1040), [Transmitted Data Manipulation](https://attack.mitre.org/techniques/T1565/002), or replay attacks ([Exploitation for Credential Access](https://attack.mitre.org/techniques/T1212)). By abusing features of common networking protocols that can determine the flow of network traffic (e.g. ARP, DNS, LLMNR, etc.), adversaries may force a device to communicate through an adversary controlled system so they can collect information or perform additional actions.(Citation: Rapid7 MiTM Basics)

LLMNR/NBT-NS Poisoning and SMB Relay
type: Class
subclass of: Adversary-in-the-Middle
subclass of: Restriction
  on property: produces
  some values from: Intranet Multicast Network Traffic
type: NamedIndividual
produces: Intranet Multicast Network Traffic
attack-id: T1557.001
definition: By responding to LLMNR/NBT-NS network traffic, adversaries may spoof an authoritative source for name resolution to force communication with an adversary controlled system. This activity may be used to collect or relay authentication materials.

ARP Cache Poisoning
type: Class
subclass of: Adversary-in-the-Middle
attack-id: T1557.002
definition: Adversaries may poison Address Resolution Protocol (ARP) caches to position themselves between the communication of two or more networked devices. This activity may be used to enable follow-on behaviors such as [Network Sniffing](https://attack.mitre.org/techniques/T1040) or [Transmitted Data Manipulation](https://attack.mitre.org/techniques/T1565/002).

DHCP Spoofing
type: Class
subclass of: Adversary-in-the-Middle
subclass of: Restriction
  on property: creates
  some values from: DHCP Network Traffic
type: NamedIndividual
creates: DHCP Network Traffic
attack-id: T1557.003
definition: Adversaries may redirect network traffic to adversary-owned systems by spoofing Dynamic Host Configuration Protocol (DHCP) traffic and acting as a malicious DHCP server on the victim network. By achieving the adversary-in-the-middle (AiTM) position, adversaries may collect network communications, including passed credentials, especially those sent over insecure, unencrypted protocols. This may also enable follow-on behaviors such as [Network Sniffing](https://attack.mitre.org/techniques/T1040) or [Transmitted Data Manipulation](https://attack.mitre.org/techniques/T1565/002).

Evil Twin
type: Class
subclass of: Adversary-in-the-Middle
attack-id: T1557.004
definition: Adversaries may host seemingly genuine Wi-Fi access points to deceive users into connecting to malicious networks as a way of supporting follow-on behaviors such as [Network Sniffing](https://attack.mitre.org/techniques/T1040), [Transmitted Data Manipulation](https://attack.mitre.org/techniques/T1565/002), or [Input Capture](https://attack.mitre.org/techniques/T1056).(Citation: Australia ‘Evil Twin’)

Steal or Forge Kerberos Tickets
type: Class
subclass of: Credential Access Technique
subclass of: Restriction
  on property: may-access
  some values from: Kerberos Ticket
subclass of: Restriction
  on property: may-create
  some values from: Kerberos Ticket
type: NamedIndividual
may-access: Kerberos Ticket
may-create: Kerberos Ticket
attack-id: T1558
definition: Adversaries may attempt to subvert Kerberos authentication by stealing or forging Kerberos tickets to enable [Pass the Ticket](https://attack.mitre.org/techniques/T1550/003). Kerberos is an authentication protocol widely used in modern Windows domain environments. In Kerberos environments, referred to as “realms”, there are three basic participants: client, service, and Key Distribution Center (KDC).(Citation: ADSecurity Kerberos Ring Decoder) Clients request access to a service and through the exchange of Kerberos tickets, originating from KDC, they are granted access after having successfully authenticated. The KDC is responsible for both authentication and ticket granting. Adversaries may attempt to abuse Kerberos by stealing tickets or forging tickets to enable unauthorized access.

Golden Ticket
type: Class
subclass of: Steal or Forge Kerberos Tickets
subclass of: Restriction
  on property: forges
  some values from: Kerberos Ticket Granting Ticket
type: NamedIndividual
forges: Kerberos Ticket Granting Ticket
attack-id: T1558.001
definition: Adversaries who have the KRBTGT account password hash may forge Kerberos ticket-granting tickets (TGT), also known as a golden ticket.(Citation: AdSecurity Kerberos GT Aug 2015) Golden tickets enable adversaries to generate authentication material for any account in Active Directory.(Citation: CERT-EU Golden Ticket Protection)

Silver Ticket
type: Class
subclass of: Steal or Forge Kerberos Tickets
attack-id: T1558.002
definition: Adversaries who have the password hash of a target service account (e.g. SharePoint, MSSQL) may forge Kerberos ticket granting service (TGS) tickets, also known as silver tickets. Kerberos TGS tickets are also known as service tickets.(Citation: ADSecurity Silver Tickets)

Kerberoasting
type: Class
subclass of: Steal or Forge Kerberos Tickets
subclass of: Restriction
  on property: may-produce
  some values from: RPC Network Traffic
type: NamedIndividual
may-produce: RPC Network Traffic
attack-id: T1558.003
definition: Service Provider Name (SPN) scanning is one way to gather hashes, which results in RPC calls conforming to the NSPI protocol.

AS-REP Roasting
type: Class
subclass of: Steal or Forge Kerberos Tickets
attack-id: T1558.004
definition: Adversaries may reveal credentials of accounts that have disabled Kerberos preauthentication by [Password Cracking](https://attack.mitre.org/techniques/T1110/002) Kerberos messages.(Citation: Harmj0y Roasting AS-REPs Jan 2017)

Ccache Files
type: Class
subclass of: Steal or Forge Kerberos Tickets
attack-id: T1558.005
definition: Adversaries may attempt to steal Kerberos tickets stored in credential cache files (or ccache). These files are used for short term storage of a user's active session credentials. The ccache file is created upon user authentication and allows for access to multiple services without the user having to re-enter credentials.

Inter-Process Communication
type: Class
subclass of: Execution Technique
subclass of: Restriction
  on property: injects
  some values from: Interprocess Communication
type: NamedIndividual
injects: Interprocess Communication
attack-id: T1559
definition: Adversaries may abuse inter-process communication (IPC) mechanisms for local code or command execution. IPC is typically used by processes to share data, communicate with each other, or synchronize execution. IPC is also commonly used to avoid situations such as deadlocks, which occurs when processes are stuck in a cyclic waiting pattern.

Component Object Model
type: Class
subclass of: Inter-Process Communication
attack-id: T1559.001
definition: Adversaries may use the Windows Component Object Model (COM) for local code execution. COM is an inter-process communication (IPC) component of the native Windows application programming interface (API) that enables interaction between software objects, or executable code that implements one or more interfaces.(Citation: Fireeye Hunting COM June 2019) Through COM, a client object can call methods of server objects, which are typically binary Dynamic Link Libraries (DLL) or executables (EXE).(Citation: Microsoft COM) Remote COM execution is facilitated by [Remote Services](https://attack.mitre.org/techniques/T1021) such as [Distributed Component Object Model](https://attack.mitre.org/techniques/T1021/003) (DCOM).(Citation: Fireeye Hunting COM June 2019)

Dynamic Data Exchange
type: Class
subclass of: Inter-Process Communication
attack-id: T1559.002
definition: Adversaries may use Windows Dynamic Data Exchange (DDE) to execute arbitrary commands. DDE is a client-server protocol for one-time and/or continuous inter-process communication (IPC) between applications. Once a link is established, applications can autonomously exchange transactions consisting of strings, warm data links (notifications when a data item changes), hot data links (duplications of changes to a data item), and requests for command execution.

XPC Services
type: Class
subclass of: Inter-Process Communication
attack-id: T1559.003
definition: Adversaries can provide malicious content to an XPC service daemon for local code execution. macOS uses XPC services for basic inter-process communication between various processes, such as between the XPC Service daemon and third-party application privileged helper tools. Applications can send messages to the XPC Service daemon, which runs as root, using the low-level XPC Service C API or the high level NSXPCConnection API in order to handle tasks that require elevated privileges (such as network connections). Applications are responsible for providing the protocol definition which serves as a blueprint of the XPC services. Developers typically use XPC Services to provide applications stability and privilege separation between the application client and the daemon.(Citation: creatingXPCservices)(Citation: Designing Daemons Apple Dev)

Archive Collected Data
type: Class
subclass of: Collection Technique
subclass of: Restriction
  on property: creates
  some values from: Archive File
type: NamedIndividual
creates: Archive File
attack-id: T1560
definition: An adversary may compress and/or encrypt data that is collected prior to exfiltration. Compressing the data can help to obfuscate the collected data and minimize the amount of data sent over the network.(Citation: DOJ GRU Indictment Jul 2018) Encryption can be used to hide information that is being exfiltrated from detection or make exfiltration less conspicuous upon inspection by a defender.

Archive via Utility
type: Class
subclass of: Archive Collected Data
subclass of: Restriction
  on property: creates
  some values from: Archive File
type: NamedIndividual
creates: Archive File
attack-id: T1560.001
definition: Adversaries may use utilities to compress and/or encrypt collected data prior to exfiltration. Many utilities include functionalities to compress, encrypt, or otherwise package data into a format that is easier/more secure to transport.

Archive via Library
type: Class
subclass of: Archive Collected Data
subclass of: Restriction
  on property: creates
  some values from: Archive File
type: NamedIndividual
creates: Archive File
attack-id: T1560.002
definition: An adversary may compress or encrypt data that is collected prior to exfiltration using 3rd party libraries. Many libraries exist that can archive data, including [Python](https://attack.mitre.org/techniques/T1059/006) rarfile (Citation: PyPI RAR), libzip (Citation: libzip), and zlib (Citation: Zlib Github). Most libraries include functionality to encrypt and/or compress data.

Archive via Custom Method
type: Class
subclass of: Archive Collected Data
subclass of: Restriction
  on property: creates
  some values from: Custom Archive File
type: NamedIndividual
creates: Custom Archive File
attack-id: T1560.003
definition: An adversary may compress or encrypt data that is collected prior to exfiltration using a custom method. Adversaries may choose to use custom archival methods, such as encryption with XOR or stream ciphers implemented with no external library or utility references. Custom implementations of well-known compression algorithms have also been used.(Citation: ESET Sednit Part 2)

Disk Wipe
type: Class
subclass of: Impact Technique
attack-id: T1561
definition: Adversaries may wipe or corrupt raw disk data on specific systems or in large numbers in a network to interrupt availability to system and network resources. With direct write access to a disk, adversaries may attempt to overwrite portions of disk data. Adversaries may opt to wipe arbitrary portions of disk data and/or wipe disk structures like the master boot record (MBR). A complete wipe of all disk sectors may be attempted.

Disk Content Wipe
type: Class
subclass of: Disk Wipe
subclass of: Restriction
  on property: may-modify
  some values from: Boot Sector
subclass of: Restriction
  on property: may-modify
  some values from: Partition
subclass of: Restriction
  on property: may-modify
  some values from: Partition Table
subclass of: Restriction
  on property: may-modify
  some values from: Volume
subclass of: Restriction
  on property: modifies
  some values from: Block Device
type: NamedIndividual
may-modify: Boot Sector
may-modify: Partition
may-modify: Partition Table
may-modify: Volume
modifies: Block Device
attack-id: T1561.001
definition: Adversaries may erase the contents of storage devices on specific systems or in large numbers in a network to interrupt availability to system and network resources.

Disk Structure Wipe
type: Class
subclass of: Disk Wipe
subclass of: Restriction
  on property: may-modify
  some values from: Boot Sector
subclass of: Restriction
  on property: may-modify
  some values from: Partition Table
type: NamedIndividual
may-modify: Boot Sector
may-modify: Partition Table
attack-id: T1561.002
definition: Adversaries may corrupt or wipe the disk data structures on a hard drive necessary to boot a system; targeting specific critical systems or in large numbers in a network to interrupt availability to system and network resources.

Impair Defenses
type: Class
subclass of: Defense Evasion Technique
attack-id: T1562
definition: Adversaries may maliciously modify components of a victim environment in order to hinder or disable defensive mechanisms. This not only involves impairing preventative defenses, such as firewalls and anti-virus, but also detection capabilities that defenders can use to audit activity and identify malicious behavior. This may also span both native defenses as well as supplemental capabilities installed by users and administrators.

Disable or Modify Tools
type: Class
subclass of: Impair Defenses
subclass of: Restriction
  on property: disables
  some values from: Operating System Process
type: NamedIndividual
disables: Operating System Process
attack-id: T1562.001
definition: Adversaries may modify and/or disable security tools to avoid possible detection of their malware/tools and activities. This may take many forms, such as killing security software processes or services, modifying / deleting Registry keys or configuration files so that tools do not operate properly, or other methods to interfere with security tools scanning or reporting information. Adversaries may also disable updates to prevent the latest security patches from reaching tools on victim systems.(Citation: SCADAfence_ransomware)

Disable Windows Event Logging
type: Class
subclass of: Impair Defenses
subclass of: Restriction
  on property: may-modify
  some values from: Application Configuration
subclass of: Restriction
  on property: may-modify
  some values from: Operating System Configuration Component
type: NamedIndividual
may-modify: Application Configuration
may-modify: Operating System Configuration Component
attack-id: T1562.002
definition: Adversaries may disable Windows event logging to limit data that can be leveraged for detections and audits. Windows event logs record user and system activity such as login attempts, process creation, and much more.(Citation: Windows Log Events) This data is used by security tools and analysts to generate detections.

Impair Command History Logging
type: Class
subclass of: Impair Defenses
subclass of: Restriction
  on property: may-modify
  some values from: User Init Script
subclass of: Restriction
  on property: may-modify
  some values from: Windows Registry Key
subclass of: Restriction
  on property: modifies
  some values from: Process Environment Variable
type: NamedIndividual
may-modify: User Init Script
may-modify: Windows Registry Key
modifies: Process Environment Variable
attack-id: T1562.003
definition: Adversaries may impair command history logging to hide commands they run on a compromised system. Various command interpreters keep track of the commands users type in their terminal so that users can retrace what they've done.

Disable or Modify System Firewall
type: Class
subclass of: Impair Defenses
subclass of: Restriction
  on property: modifies
  some values from: System Firewall Configuration
type: NamedIndividual
modifies: System Firewall Configuration
attack-id: T1562.004
definition: Adversaries may disable or modify system firewalls in order to bypass controls limiting network usage. Changes could be disabling the entire mechanism as well as adding, deleting, or modifying particular rules. This can be done numerous ways depending on the operating system, including via command-line, editing Windows Registry keys, and Windows Control Panel.

Indicator Blocking
type: Class
subclass of: Impair Defenses
attack-id: T1562.006
definition: An adversary may attempt to block indicators or events typically captured by sensors from being gathered and analyzed. This could include maliciously redirecting(Citation: Microsoft Lamin Sept 2017) or even disabling host-based sensors, such as Event Tracing for Windows (ETW)(Citation: Microsoft About Event Tracing 2018), by tampering settings that control the collection and flow of event telemetry.(Citation: Medium Event Tracing Tampering 2018) These settings may be stored on the system in configuration files and/or in the Registry as well as being accessible via administrative utilities such as [PowerShell](https://attack.mitre.org/techniques/T1059/001) or [Windows Management Instrumentation](https://attack.mitre.org/techniques/T1047).

Disable or Modify Cloud Firewall
type: Class
subclass of: Impair Defenses
attack-id: T1562.007
definition: Adversaries may disable or modify a firewall within a cloud environment to bypass controls that limit access to cloud resources. Cloud firewalls are separate from system firewalls that are described in [Disable or Modify System Firewall](https://attack.mitre.org/techniques/T1562/004).

Disable or Modify Cloud Logs
type: Class
subclass of: Impair Defenses
attack-id: T1562.008
definition: An adversary may disable or modify cloud logging capabilities and integrations to limit what data is collected on their activities and avoid detection. Cloud environments allow for collection and analysis of audit and application logs that provide insight into what activities a user does within the environment. If an adversary has sufficient permissions, they can disable or modify logging to avoid detection of their activities.

Safe Mode Boot
type: Class
subclass of: Impair Defenses
subclass of: Restriction
  on property: disables
  some values from: Endpoint Sensor
subclass of: Restriction
  on property: disables
  some values from: System Configuration Init Database Record
subclass of: Restriction
  on property: may-modify
  some values from: Endpoint Health Beacon
type: NamedIndividual
disables: Endpoint Sensor
disables: System Configuration Init Database Record
may-modify: Endpoint Health Beacon
attack-id: T1562.009
definition: Adversaries may abuse Windows safe mode to disable endpoint defenses. Safe mode starts up the Windows operating system with a limited set of drivers and services. Third-party security software such as endpoint detection and response (EDR) tools may not start after booting Windows in safe mode. There are two versions of safe mode: Safe Mode and Safe Mode with Networking. It is possible to start additional services after a safe mode boot.(Citation: Microsoft Safe Mode)(Citation: Sophos Snatch Ransomware 2019)

Downgrade Attack
type: Class
subclass of: Impair Defenses
subclass of: Restriction
  on property: accesses
  some values from: Legacy System
type: NamedIndividual
accesses: Legacy System
attack-id: T1562.010
definition: Adversaries may downgrade or use a version of system features that may be outdated, vulnerable, and/or does not support updated security controls. Downgrade attacks typically take advantage of a system’s backward compatibility to force it into less secure modes of operation.

Spoof Security Alerting
type: Class
subclass of: Impair Defenses
attack-id: T1562.011
definition: Adversaries may spoof security alerting from tools, presenting false evidence to impair defenders’ awareness of malicious activity.(Citation: BlackBasta) Messages produced by defensive tools contain information about potential security events as well as the functioning status of security software and the system. Security reporting messages are important for monitoring the normal operation of a system and identifying important events that can signal a security incident.

Disable or Modify Linux Audit System
type: Class
subclass of: Impair Defenses
attack-id: T1562.012
definition: Adversaries may disable or modify the Linux audit system to hide malicious activity and avoid detection. Linux admins use the Linux Audit system to track security-relevant information on a system. The Linux Audit system operates at the kernel-level and maintains event logs on application and system activity such as process, network, file, and login events based on pre-configured rules.

Remote Service Session Hijacking
type: Class
subclass of: Lateral Movement Technique
subclass of: Restriction
  on property: accesses
  some values from: Remote Session
subclass of: Restriction
  on property: produces
  some values from: Administrative Network Traffic
type: NamedIndividual
accesses: Remote Session
produces: Administrative Network Traffic
attack-id: T1563
definition: Adversaries may take control of preexisting sessions with remote services to move laterally in an environment. Users may use valid credentials to log into a service specifically designed to accept remote connections, such as telnet, SSH, and RDP. When a user logs into a service, a session will be established that will allow them to maintain a continuous interaction with that service.

SSH Hijacking
type: Class
subclass of: Remote Service Session Hijacking
subclass of: Restriction
  on property: accesses
  some values from: SSH Session
type: NamedIndividual
accesses: SSH Session
attack-id: T1563.001
definition: Adversaries may hijack a legitimate user's SSH session to move laterally within an environment. Secure Shell (SSH) is a standard means of remote access on Linux and macOS systems. It allows a user to connect to another system via an encrypted tunnel, commonly authenticating through a password, certificate or the use of an asymmetric encryption key pair.

RDP Hijacking
type: Class
subclass of: Remote Service Session Hijacking
subclass of: Restriction
  on property: accesses
  some values from: RDP Session
type: NamedIndividual
accesses: RDP Session
attack-id: T1563.002
definition: Adversaries may hijack a legitimate user’s remote desktop session to move laterally within an environment. Remote desktop is a common feature in operating systems. It allows a user to log into an interactive session with a system desktop graphical user interface on a remote system. Microsoft refers to its implementation of the Remote Desktop Protocol (RDP) as Remote Desktop Services (RDS).(Citation: TechNet Remote Desktop Services)

Hide Artifacts
type: Class
subclass of: Defense Evasion Technique
attack-id: T1564
definition: Adversaries may attempt to hide artifacts associated with their behaviors to evade detection. Operating systems may have features to hide various artifacts, such as important system files and administrative task execution, to avoid disrupting user work environments and prevent users from changing files or features on the system. Adversaries may abuse these features to hide artifacts such as files, directories, user accounts, or other system activity to evade detection.(Citation: Sofacy Komplex Trojan)(Citation: Cybereason OSX Pirrit)(Citation: MalwareBytes ADS July 2015)

Hidden Files and Directories
type: Class
subclass of: Hide Artifacts
subclass of: Restriction
  on property: modifies
  some values from: File System Metadata
type: NamedIndividual
modifies: File System Metadata
attack-id: T1564.001
definition: Adversaries may set files and directories to be hidden to evade detection mechanisms. To prevent normal users from accidentally changing special files on a system, most operating systems have the concept of a ‘hidden’ file. These files don’t show up when a user browses the file system with a GUI or when using normal commands on the command line. Users must explicitly ask to show the hidden files either via a series of Graphical User Interface (GUI) prompts or with command line switches (dir /a for Windows and ls –a for Linux and macOS).

Hidden Users
type: Class
subclass of: Hide Artifacts
subclass of: Restriction
  on property: modifies
  some values from: User Init Configuration File
type: NamedIndividual
modifies: User Init Configuration File
attack-id: T1564.002
definition: Adversaries may use hidden users to hide the presence of user accounts they create or modify. Administrators may want to hide users when there are many user accounts on a given system or if they want to hide their administrative or other management accounts from other users.

Hidden Window
type: Class
subclass of: Hide Artifacts
subclass of: Restriction
  on property: may-modify
  some values from: Property List File
subclass of: Restriction
  on property: may-modify
  some values from: System Configuration Database
type: NamedIndividual
may-modify: Property List File
may-modify: System Configuration Database
attack-id: T1564.003
definition: Adversaries may use hidden windows to conceal malicious activity from the plain sight of users. In some cases, windows that would typically be displayed when an application carries out an operation can be hidden. This may be utilized by system administrators to avoid disrupting user work environments when carrying out administrative tasks.

NTFS File Attributes
type: Class
subclass of: Hide Artifacts
subclass of: Restriction
  on property: modifies
  some values from: File System Metadata
type: NamedIndividual
modifies: File System Metadata
attack-id: T1564.004
definition: Adversaries may use NTFS file attributes to hide their malicious data in order to evade detection. Every New Technology File System (NTFS) formatted partition contains a Master File Table (MFT) that maintains a record for every file/directory on the partition. (Citation: SpectorOps Host-Based Jul 2017) Within MFT entries are file attributes, (Citation: Microsoft NTFS File Attributes Aug 2010) such as Extended Attributes (EA) and Data [known as Alternate Data Streams (ADSs) when more than one Data attribute is present], that can be used to store arbitrary data (and even complete files). (Citation: SpectorOps Host-Based Jul 2017) (Citation: Microsoft File Streams) (Citation: MalwareBytes ADS July 2015) (Citation: Microsoft ADS Mar 2014)

Hidden File System
type: Class
subclass of: Hide Artifacts
subclass of: Restriction
  on property: may-modify
  some values from: System Configuration Database
subclass of: Restriction
  on property: modifies
  some values from: Storage
type: NamedIndividual
may-modify: System Configuration Database
modifies: Storage
attack-id: T1564.005
definition: Adversaries may use a hidden file system to conceal malicious activity from users and security tools. File systems provide a structure to store and access data from physical storage. Typically, a user engages with a file system through applications that allow them to access files and directories, which are an abstraction from their physical location (ex: disk sector). Standard file systems include FAT, NTFS, ext4, and APFS. File systems can also contain other structures, such as the Volume Boot Record (VBR) and Master File Table (MFT) in NTFS.(Citation: MalwareTech VFS Nov 2014)

Run Virtual Instance
type: Class
subclass of: Hide Artifacts
subclass of: Restriction
  on property: creates
  some values from: File
subclass of: Restriction
  on property: executes
  some values from: Virtualization Software
subclass of: Restriction
  on property: may-add
  some values from: Virtualization Software
subclass of: Restriction
  on property: may-create
  some values from: Directory
type: NamedIndividual
creates: File
executes: Virtualization Software
may-add: Virtualization Software
may-create: Directory
attack-id: T1564.006
definition: Adversaries may carry out malicious operations using a virtual instance to avoid detection. A wide variety of virtualization technologies exist that allow for the emulation of a computer or computing environment. By running malicious code inside of a virtual instance, adversaries can hide artifacts associated with their behavior from security tools that are unable to monitor activity inside the virtual instance. Additionally, depending on the virtual networking implementation (ex: bridged adapter), network traffic generated by the virtual instance can be difficult to trace back to the compromised host as the IP address and hostname might not match known values.(Citation: SingHealth Breach Jan 2019)

VBA Stomping
type: Class
subclass of: Hide Artifacts
subclass of: Restriction
  on property: modifies
  some values from: Office Application File
type: NamedIndividual
modifies: Office Application File
attack-id: T1564.007
definition: Adversaries may hide malicious Visual Basic for Applications (VBA) payloads embedded within MS Office documents by replacing the VBA source code with benign data.(Citation: FireEye VBA stomp Feb 2020)

Email Hiding Rules
type: Class
subclass of: Hide Artifacts
subclass of: Restriction
  on property: may-create
  some values from: Email Rule
subclass of: Restriction
  on property: may-modify
  some values from: Email Rule
subclass of: Restriction
  on property: modifies
  some values from: Application Configuration
type: NamedIndividual
may-create: Email Rule
may-modify: Email Rule
modifies: Application Configuration
attack-id: T1564.008
definition: Adversaries may use email rules to hide inbound emails in a compromised user's mailbox. Many email clients allow users to create inbox rules for various email functions, including moving emails to other folders, marking emails as read, or deleting emails. Rules may be created or modified within email clients or through external features such as the New-InboxRule or Set-InboxRule [PowerShell](https://attack.mitre.org/techniques/T1059/001) cmdlets on Windows systems.(Citation: Microsoft Inbox Rules)(Citation: MacOS Email Rules)(Citation: Microsoft New-InboxRule)(Citation: Microsoft Set-InboxRule)

Resource Forking
type: Class
subclass of: Hide Artifacts
subclass of: Restriction
  on property: may-create
  some values from: Resource Fork
subclass of: Restriction
  on property: may-modify
  some values from: Resource Fork
type: NamedIndividual
may-create: Resource Fork
may-modify: Resource Fork
attack-id: T1564.009
definition: Adversaries may abuse resource forks to hide malicious code or executables to evade detection and bypass security applications. A resource fork provides applications a structured way to store resources such as thumbnail images, menu definitions, icons, dialog boxes, and code.(Citation: macOS Hierarchical File System Overview) Usage of a resource fork is identifiable when displaying a file’s extended attributes, using ls -l@ or xattr -l commands. Resource forks have been deprecated and replaced with the application bundle structure. Non-localized resources are placed at the top level directory of an application bundle, while localized resources are placed in the /Resources folder.(Citation: Resource and Data Forks)(Citation: ELC Extended Attributes)

Process Argument Spoofing
type: Class
subclass of: Hide Artifacts
attack-id: T1564.010
definition: Adversaries may attempt to hide process command-line arguments by overwriting process memory. Process command-line arguments are stored in the process environment block (PEB), a data structure used by Windows to store various information about/used by a process. The PEB includes the process command-line arguments that are referenced when executing the process. When a process is created, defensive tools/sensors that monitor process creations may retrieve the process arguments from the PEB.(Citation: Microsoft PEB 2021)(Citation: Xpn Argue Like Cobalt 2019)

Ignore Process Interrupts
type: Class
subclass of: Hide Artifacts
attack-id: T1564.011
definition: Adversaries may evade defensive mechanisms by executing commands that hide from process interrupt signals. Many operating systems use signals to deliver messages to control process behavior. Command interpreters often include specific commands/flags that ignore errors and other hangups, such as when the user of the active session logs off.(Citation: Linux Signal Man) These interrupt signals may also be used by defensive tools and/or analysts to pause or terminate specified running processes.

File/Path Exclusions
type: Class
subclass of: Hide Artifacts
attack-id: T1564.012
definition: Adversaries may attempt to hide their file-based artifacts by writing them to specific folders or file names excluded from antivirus (AV) scanning and other defensive capabilities. AV and other file-based scanners often include exclusions to optimize performance as well as ease installation and legitimate use of applications. These exclusions may be contextual (e.g., scans are only initiated in response to specific triggering events/alerts), but are also often hardcoded strings referencing specific folders and/or files assumed to be trusted and legitimate.(Citation: Microsoft File Folder Exclusions)

Data Manipulation
type: Class
subclass of: Impact Technique
attack-id: T1565
definition: Adversaries may insert, delete, or manipulate data in order to influence external outcomes or hide activity, thus threatening the integrity of the data.(Citation: Sygnia Elephant Beetle Jan 2022) By manipulating data, adversaries may attempt to affect a business process, organizational understanding, or decision making.

Stored Data Manipulation
type: Class
subclass of: Data Manipulation
subclass of: Restriction
  on property: modifies
  some values from: File
type: NamedIndividual
modifies: File
attack-id: T1565.001
definition: Adversaries may insert, delete, or manipulate data at rest in order to influence external outcomes or hide activity, thus threatening the integrity of the data.(Citation: FireEye APT38 Oct 2018)(Citation: DOJ Lazarus Sony 2018) By manipulating stored data, adversaries may attempt to affect a business process, organizational understanding, and decision making.

Transmitted Data Manipulation
type: Class
subclass of: Data Manipulation
subclass of: Restriction
  on property: may-modify
  some values from: Network Traffic
type: NamedIndividual
may-modify: Network Traffic
attack-id: T1565.002
definition: Adversaries may alter data en route to storage or other systems in order to manipulate external outcomes or hide activity, thus threatening the integrity of the data.(Citation: FireEye APT38 Oct 2018)(Citation: DOJ Lazarus Sony 2018) By manipulating transmitted data, adversaries may attempt to affect a business process, organizational understanding, and decision making.

Runtime Data Manipulation
type: Class
subclass of: Data Manipulation
subclass of: Restriction
  on property: may-modify
  some values from: Executable File
type: NamedIndividual
may-modify: Executable File
attack-id: T1565.003
definition: Adversaries may modify systems in order to manipulate the data as it is accessed and displayed to an end user, thus threatening the integrity of the data.(Citation: FireEye APT38 Oct 2018)(Citation: DOJ Lazarus Sony 2018) By manipulating runtime data, adversaries may attempt to affect a business process, organizational understanding, and decision making.

Phishing
type: Class
subclass of: Initial Access Technique
attack-id: T1566
definition: Adversaries may send phishing messages to gain access to victim systems. All forms of phishing are electronically delivered social engineering. Phishing can be targeted, known as spearphishing. In spearphishing, a specific individual, company, or industry will be targeted by the adversary. More generally, adversaries can conduct non-targeted phishing, such as in mass malware spam campaigns.

Spearphishing Attachment
type: Class
subclass of: Phishing
subclass of: Restriction
  on property: produces
  some values from: Email
subclass of: Restriction
  on property: produces
  some values from: Inbound Internet Mail Traffic
type: NamedIndividual
produces: Email
produces: Inbound Internet Mail Traffic
attack-id: T1566.001
definition: Adversaries may send spearphishing emails with a malicious attachment in an attempt to gain access to victim systems. Spearphishing attachment is a specific variant of spearphishing. Spearphishing attachment is different from other forms of spearphishing in that it employs the use of malware attached to an email. All forms of spearphishing are electronically delivered social engineering targeted at a specific individual, company, or industry. In this scenario, adversaries attach a file to the spearphishing email and usually rely upon [User Execution](https://attack.mitre.org/techniques/T1204) to gain execution.(Citation: Unit 42 DarkHydrus July 2018) Spearphishing may also involve social engineering techniques, such as posing as a trusted source.

Spearphishing Link
type: Class
subclass of: Phishing
subclass of: Restriction
  on property: produces
  some values from: Email
subclass of: Restriction
  on property: produces
  some values from: Inbound Internet Mail Traffic
subclass of: Restriction
  on property: produces
  some values from: URL
type: NamedIndividual
produces: Email
produces: Inbound Internet Mail Traffic
produces: URL
attack-id: T1566.002
definition: Adversaries may send spearphishing emails with a malicious link in an attempt to gain access to victim systems. Spearphishing with a link is a specific variant of spearphishing. It is different from other forms of spearphishing in that it employs the use of links to download malware contained in email, instead of attaching malicious files to the email itself, to avoid defenses that may inspect email attachments. Spearphishing may also involve social engineering techniques, such as posing as a trusted source.

Spearphishing via Service
type: Class
subclass of: Phishing
subclass of: Restriction
  on property: produces
  some values from: File
subclass of: Restriction
  on property: produces
  some values from: URL
type: NamedIndividual
produces: File
produces: URL
attack-id: T1566.003
definition: Adversaries may send spearphishing messages via third-party services in an attempt to gain access to victim systems. Spearphishing via service is a specific variant of spearphishing. It is different from other forms of spearphishing in that it employs the use of third party services rather than directly via enterprise email channels.

Spearphishing Voice
type: Class
subclass of: Phishing
attack-id: T1566.004
definition: Adversaries may use voice communications to ultimately gain access to victim systems. Spearphishing voice is a specific variant of spearphishing. It is different from other forms of spearphishing in that is employs the use of manipulating a user into providing access to systems through a phone call or other forms of voice communications. Spearphishing frequently involves social engineering techniques, such as posing as a trusted source (ex: [Impersonation](https://attack.mitre.org/techniques/T1656)) and/or creating a sense of urgency or alarm for the recipient.

Exfiltration Over Web Service
type: Class
subclass of: Exfiltration Technique
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Web Traffic
type: NamedIndividual
produces: Outbound Internet Web Traffic
attack-id: T1567
definition: Adversaries may use an existing, legitimate external Web service to exfiltrate data rather than their primary command and control channel. Popular Web services acting as an exfiltration mechanism may give a significant amount of cover due to the likelihood that hosts within a network are already communicating with them prior to compromise. Firewall rules may also already exist to permit traffic to these services.

Exfiltration to Code Repository
type: Class
subclass of: Exfiltration Over Web Service
subclass of: Restriction
  on property: may-produce
  some values from: Outbound Internet Encrypted Remote Terminal Traffic
subclass of: Restriction
  on property: may-produce
  some values from: Outbound Internet Encrypted Web Traffic
type: NamedIndividual
may-produce: Outbound Internet Encrypted Remote Terminal Traffic
may-produce: Outbound Internet Encrypted Web Traffic
attack-id: T1567.001
definition: Adversaries may exfiltrate data to a code repository rather than over their primary command and control channel. Code repositories are often accessible via an API (ex: https://api.github.com). Access to these APIs are often over HTTPS, which gives the adversary an additional level of protection.

Exfiltration to Cloud Storage
type: Class
subclass of: Exfiltration Over Web Service
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Encrypted Web Traffic
type: NamedIndividual
produces: Outbound Internet Encrypted Web Traffic
attack-id: T1567.002
definition: Adversaries may exfiltrate data to a cloud storage service rather than over their primary command and control channel. Cloud storage services allow for the storage, edit, and retrieval of data from a remote cloud storage server over the Internet.

Exfiltration to Text Storage Sites
type: Class
subclass of: Exfiltration Over Web Service
attack-id: T1567.003
definition: Adversaries may exfiltrate data to text storage sites instead of their primary command and control channel. Text storage sites, such as pastebin[.]com, are commonly used by developers to share code and other information.

Exfiltration Over Webhook
type: Class
subclass of: Exfiltration Over Web Service
attack-id: T1567.004
definition: Adversaries may exfiltrate data to a webhook endpoint rather than over their primary command and control channel. Webhooks are simple mechanisms for allowing a server to push data over HTTP/S to a client without the need for the client to continuously poll the server.(Citation: RedHat Webhooks) Many public and commercial services, such as Discord, Slack, and `webhook.site`, support the creation of webhook endpoints that can be used by other services, such as Github, Jira, or Trello.(Citation: Discord Intro to Webhooks) When changes happen in the linked services (such as pushing a repository update or modifying a ticket), these services will automatically post the data to the webhook endpoint for use by the consuming application.

Dynamic Resolution
type: Class
subclass of: Command and Control Technique
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet DNS Lookup Traffic
type: NamedIndividual
produces: Outbound Internet DNS Lookup Traffic
attack-id: T1568
definition: Adversaries may dynamically establish connections to command and control infrastructure to evade common detections and remediations. This may be achieved by using malware that shares a common algorithm with the infrastructure the adversary uses to receive the malware's communications. These calculations can be used to dynamically adjust parameters such as the domain name, IP address, or port number the malware uses for command and control.

Fast Flux DNS
type: Class
subclass of: Dynamic Resolution
attack-id: T1568.001
definition: Adversaries may use Fast Flux DNS to hide a command and control channel behind an array of rapidly changing IP addresses linked to a single domain resolution. This technique uses a fully qualified domain name, with multiple IP addresses assigned to it which are swapped with high frequency, using a combination of round robin IP addressing and short Time-To-Live (TTL) for a DNS resource record.(Citation: MehtaFastFluxPt1)(Citation: MehtaFastFluxPt2)(Citation: Fast Flux - Welivesecurity)

Domain Generation Algorithms
type: Class
subclass of: Dynamic Resolution
attack-id: T1568.002
definition: Adversaries may make use of Domain Generation Algorithms (DGAs) to dynamically identify a destination domain for command and control traffic rather than relying on a list of static IP addresses or domains. This has the advantage of making it much harder for defenders to block, track, or take over the command and control channel, as there potentially could be thousands of domains that malware can check for instructions.(Citation: Cybereason Dissecting DGAs)(Citation: Cisco Umbrella DGA)(Citation: Unit 42 DGA Feb 2019)

DNS Calculation
type: Class
subclass of: Dynamic Resolution
attack-id: T1568.003
definition: Adversaries may perform calculations on addresses returned in DNS results to determine which port and IP address to use for command and control, rather than relying on a predetermined port number or the actual returned IP address. A IP and/or port number calculation can be used to bypass egress filtering on a C2 channel.(Citation: Meyers Numbered Panda)

System Services
type: Class
subclass of: Execution Technique
attack-id: T1569
definition: This technique has been deprecated.

Launchctl
type: Class
subclass of: System Services
attack-id: T1569.001
definition: Adversaries may abuse launchctl to execute commands or programs. Launchctl interfaces with launchd, the service management framework for macOS. Launchctl supports taking subcommands on the command-line, interactively, or even redirected from standard input.(Citation: Launchctl Man)

Service Execution
type: Class
subclass of: System Services
attack-id: T1569.002
definition: Adversaries may abuse the Windows service control manager to execute malicious commands or payloads. The Windows service control manager (services.exe) is an interface to manage and manipulate services.(Citation: Microsoft Service Control Manager) The service control manager is accessible to users via GUI components as well as system utilities such as sc.exe and [Net](https://attack.mitre.org/software/S0039).

Lateral Tool Transfer
type: Class
subclass of: Lateral Movement Technique
subclass of: Restriction
  on property: produces
  some values from: Intranet File Transfer Traffic
type: NamedIndividual
produces: Intranet File Transfer Traffic
attack-id: T1570
definition: Adversaries may transfer tools or other files between systems in a compromised environment. Once brought into the victim environment (i.e., [Ingress Tool Transfer](https://attack.mitre.org/techniques/T1105)) files may then be copied from one system to another to stage adversary tools or other files over the course of an operation.

Non-Standard Port
type: Class
subclass of: Command and Control Technique
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Network Traffic
type: NamedIndividual
produces: Outbound Internet Network Traffic
attack-id: T1571
definition: Adversaries may communicate using a protocol and port pairing that are typically not associated. For example, HTTPS over port 8088(Citation: Symantec Elfin Mar 2019) or port 587(Citation: Fortinet Agent Tesla April 2018) as opposed to the traditional port 443. Adversaries may make changes to the standard port used by a protocol to bypass filtering or muddle analysis/parsing of network data.

Protocol Tunneling
type: Class
subclass of: Command and Control Technique
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Network Traffic
type: NamedIndividual
produces: Outbound Internet Network Traffic
attack-id: T1572
definition: Adversaries may tunnel network communications to and from a victim system within a separate protocol to avoid detection/network filtering and/or enable access to otherwise unreachable systems. Tunneling involves explicitly encapsulating a protocol within another. This behavior may conceal malicious traffic by blending in with existing traffic and/or provide an outer layer of encryption (similar to a VPN). Tunneling could also enable routing of network packets that would otherwise not reach their intended destination, such as SMB, RDP, or other traffic that would be filtered by network appliances or not routed over the Internet.

Encrypted Channel
type: Class
subclass of: Command and Control Technique
subclass of: Restriction
  on property: produces
  some values from: Outbound Internet Encrypted Traffic
type: NamedIndividual
produces: Outbound Internet Encrypted Traffic
attack-id: T1573
definition: Adversaries may employ an encryption algorithm to conceal command and control traffic rather than relying on any inherent protections provided by a communication protocol. Despite the use of a secure algorithm, these implementations may be vulnerable to reverse engineering if secret keys are encoded and/or generated within malware samples/configuration files.
alternative label: Custom Command and Control Protocol
alternative label: Custom Cryptographic Protocol
alternative label: Multilayer Encryption

Symmetric Cryptography
type: Class
subclass of: Encrypted Channel
subclass of: Restriction
  on property: creates
  some values from: Outbound Internet Encrypted Traffic
type: NamedIndividual
creates: Outbound Internet Encrypted Traffic
attack-id: T1573.001
definition: Adversaries may employ a known symmetric encryption algorithm to conceal command and control traffic rather than relying on any inherent protections provided by a communication protocol. Symmetric encryption algorithms use the same key for plaintext encryption and ciphertext decryption. Common symmetric encryption algorithms include AES, DES, 3DES, Blowfish, and RC4.

Asymmetric Cryptography
type: Class
subclass of: Encrypted Channel
subclass of: Restriction
  on property: creates
  some values from: Outbound Internet Encrypted Traffic
subclass of: Restriction
  on property: may-transfer
  some values from: Certificate File
type: NamedIndividual
creates: Outbound Internet Encrypted Traffic
may-transfer: Certificate File
attack-id: T1573.002
definition: Adversaries may employ a known asymmetric encryption algorithm to conceal command and control traffic rather than relying on any inherent protections provided by a communication protocol. Asymmetric cryptography, also known as public key cryptography, uses a keypair per party: one public that can be freely distributed, and one private. Due to how the keys are generated, the sender encrypts data with the receiver’s public key and the receiver decrypts the data with their private key. This ensures that only the intended recipient can read the encrypted data. Common public key encryption algorithms include RSA and ElGamal.

Hijack Execution Flow
type: Class
subclass of: Defense Evasion Technique
subclass of: Persistence Technique
subclass of: Privilege Escalation Technique
attack-id: T1574
definition: Adversaries may execute their own malicious payloads by hijacking the way operating systems run programs. Hijacking execution flow can be for the purposes of persistence, since this hijacked execution may reoccur over time. Adversaries may also use these mechanisms to elevate privileges or evade defenses, such as application control or other restrictions on execution.

DLL Search Order Hijacking
type: Class
subclass of: Hijack Execution Flow
subclass of: Restriction
  on property: may-create
  some values from: Shared Library File
type: NamedIndividual
may-create: Shared Library File
attack-id: T1574.001
definition: Adversaries may execute their own malicious payloads by hijacking the search order used to load DLLs. Windows systems use a common method to look for required DLLs to load into a program. (Citation: Microsoft Dynamic Link Library Search Order)(Citation: FireEye Hijacking July 2010) Hijacking DLL loads may be for the purpose of establishing persistence as well as elevating privileges and/or evading restrictions on file execution.

DLL Side-Loading
type: Class
subclass of: Hijack Execution Flow
subclass of: Restriction
  on property: may-create
  some values from: Shared Library File
subclass of: Restriction
  on property: may-modify
  some values from: Shared Library File
type: NamedIndividual
may-create: Shared Library File
may-modify: Shared Library File
attack-id: T1574.002
definition: Adversaries may execute their own malicious payloads by side-loading DLLs. Similar to [DLL Search Order Hijacking](https://attack.mitre.org/techniques/T1574/001), side-loading involves hijacking which DLL a program loads. But rather than just planting the DLL within the search order of a program then waiting for the victim application to be invoked, adversaries may directly side-load their payloads by planting then invoking a legitimate application that executes their payload(s).

Dylib Hijacking
type: Class
subclass of: Hijack Execution Flow
subclass of: Restriction
  on property: may-create
  some values from: Shared Library File
subclass of: Restriction
  on property: may-modify
  some values from: Shared Library File
type: NamedIndividual
may-create: Shared Library File
may-modify: Shared Library File
attack-id: T1574.004
definition: Adversaries may execute their own payloads by placing a malicious dynamic library (dylib) with an expected name in a path a victim application searches at runtime. The dynamic loader will try to find the dylibs based on the sequential order of the search paths. Paths to dylibs may be prefixed with @rpath, which allows developers to use relative paths to specify an array of search paths used at runtime based on the location of the executable. Additionally, if weak linking is used, such as the LC_LOAD_WEAK_DYLIB function, an application will still execute even if an expected dylib is not present. Weak linking enables developers to run an application on multiple macOS versions as new APIs are added.

Executable Installer File Permissions Weakness
type: Class
subclass of: Hijack Execution Flow
subclass of: Restriction
  on property: modifies
  some values from: Service Application
type: NamedIndividual
modifies: Service Application
attack-id: T1574.005
definition: Adversaries may execute their own malicious payloads by hijacking the binaries used by an installer. These processes may automatically execute specific binaries as part of their functionality or to perform other actions. If the permissions on the file system directory containing a target binary, or permissions on the binary itself, are improperly set, then the target binary may be overwritten with another binary using user-level permissions and executed by the original process. If the original process and thread are running under a higher permissions level, then the replaced binary will also execute under higher-level permissions, which could include SYSTEM.

Dynamic Linker Hijacking
type: Class
subclass of: Hijack Execution Flow
subclass of: Restriction
  on property: modifies
  some values from: Operating System Configuration File
type: NamedIndividual
modifies: Operating System Configuration File
attack-id: T1574.006
definition: Adversaries may execute their own malicious payloads by hijacking environment variables the dynamic linker uses to load shared libraries. During the execution preparation phase of a program, the dynamic linker loads specified absolute paths of shared libraries from environment variables and files, such as LD_PRELOAD on Linux or DYLD_INSERT_LIBRARIES on macOS. Libraries specified in environment variables are loaded first, taking precedence over system libraries with the same function name.(Citation: Man LD.SO)(Citation: TLDP Shared Libraries)(Citation: Apple Doco Archive Dynamic Libraries) These variables are often used by developers to debug binaries without needing to recompile, deconflict mapped symbols, and implement custom functions without changing the original library.(Citation: Baeldung LD_PRELOAD)

Path Interception by PATH Environment Variable
type: Class
subclass of: Hijack Execution Flow
subclass of: Restriction
  on property: creates
  some values from: Executable File
type: NamedIndividual
creates: Executable File
attack-id: T1574.007
definition: Adversaries may execute their own malicious payloads by hijacking environment variables used to load libraries. The PATH environment variable contains a list of directories (User and System) that the OS searches sequentially through in search of the binary that was called from a script or the command line.

Path Interception by Search Order Hijacking
type: Class
subclass of: Hijack Execution Flow
subclass of: Restriction
  on property: creates
  some values from: Executable File
type: NamedIndividual
creates: Executable File
attack-id: T1574.008
definition: Adversaries may execute their own malicious payloads by hijacking the search order used to load other programs. Because some programs do not call other programs using the full path, adversaries may place their own file in the directory where the calling program is located, causing the operating system to launch their malicious software at the request of the calling program.

Path Interception by Unquoted Path
type: Class
subclass of: Hijack Execution Flow
subclass of: Restriction
  on property: creates
  some values from: Executable File
type: NamedIndividual
creates: Executable File
attack-id: T1574.009
definition: Adversaries may execute their own malicious payloads by hijacking vulnerable file path references. Adversaries can take advantage of paths that lack surrounding quotations by placing an executable in a higher level directory within the path, so that Windows will choose the adversary's executable to launch.

Services File Permissions Weakness
type: Class
subclass of: Hijack Execution Flow
subclass of: Restriction
  on property: modifies
  some values from: Service Application
type: NamedIndividual
modifies: Service Application
attack-id: T1574.010
definition: Adversaries may execute their own malicious payloads by hijacking the binaries used by services. Adversaries may use flaws in the permissions of Windows services to replace the binary that is executed upon service start. These service processes may automatically execute specific binaries as part of their functionality or to perform other actions. If the permissions on the file system directory containing a target binary, or permissions on the binary itself are improperly set, then the target binary may be overwritten with another binary using user-level permissions and executed by the original process. If the original process and thread are running under a higher permissions level, then the replaced binary will also execute under higher-level permissions, which could include SYSTEM.
alternative label: Service Registry Permissions Weakness

Services Registry Permissions Weakness
type: Class
subclass of: Hijack Execution Flow
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Init Database Record
type: NamedIndividual
modifies: System Configuration Init Database Record
attack-id: T1574.011
definition: Adversaries may execute their own malicious payloads by hijacking the Registry entries used by services. Adversaries may use flaws in the permissions for Registry keys related to services to redirect from the originally specified executable to one that they control, in order to launch their own code when a service starts. Windows stores local service configuration information in the Registry under HKLM\SYSTEM\CurrentControlSet\Services. The information stored under a service's Registry keys can be manipulated to modify a service's execution parameters through tools such as the service controller, sc.exe, [PowerShell](https://attack.mitre.org/techniques/T1059/001), or [Reg](https://attack.mitre.org/software/S0075). Access to Registry keys is controlled through access control lists and user permissions. (Citation: Registry Key Security)(Citation: malware_hides_service)

COR_PROFILER
type: Class
subclass of: Hijack Execution Flow
subclass of: Restriction
  on property: adds
  some values from: Shared Library File
subclass of: Restriction
  on property: modifies
  some values from: System Configuration Database Record
type: NamedIndividual
adds: Shared Library File
modifies: System Configuration Database Record
attack-id: T1574.012
definition: Adversaries may leverage the COR_PROFILER environment variable to hijack the execution flow of programs that load the .NET CLR. The COR_PROFILER is a .NET Framework feature which allows developers to specify an unmanaged (or external of .NET) profiling DLL to be loaded into each .NET process that loads the Common Language Runtime (CLR). These profilers are designed to monitor, troubleshoot, and debug managed code executed by the .NET CLR.(Citation: Microsoft Profiling Mar 2017)(Citation: Microsoft COR_PROFILER Feb 2013)

KernelCallbackTable
type: Class
subclass of: Hijack Execution Flow
attack-id: T1574.013
definition: Adversaries may abuse the KernelCallbackTable of a process to hijack its execution flow in order to run their own payloads.(Citation: Lazarus APT January 2022)(Citation: FinFisher exposed ) The KernelCallbackTable can be found in the Process Environment Block (PEB) and is initialized to an array of graphic functions available to a GUI process once user32.dll is loaded.(Citation: Windows Process Injection KernelCallbackTable)

AppDomainManager
type: Class
subclass of: Hijack Execution Flow
attack-id: T1574.014
definition: Adversaries may execute their own malicious payloads by hijacking how the .NET `AppDomainManager` loads assemblies. The .NET framework uses the `AppDomainManager` class to create and manage one or more isolated runtime environments (called application domains) inside a process to host the execution of .NET applications. Assemblies (`.exe` or `.dll` binaries compiled to run as .NET code) may be loaded into an application domain as executable code.(Citation: Microsoft App Domains)

Modify Cloud Compute Infrastructure
type: Class
subclass of: Defense Evasion Technique
attack-id: T1578
definition: An adversary may attempt to modify a cloud account's compute service infrastructure to evade defenses. A modification to the compute service infrastructure can include the creation, deletion, or modification of one or more components such as compute instances, virtual machines, and snapshots.

Create Snapshot
type: Class
subclass of: Modify Cloud Compute Infrastructure
attack-id: T1578.001
definition: An adversary may create a snapshot or data backup within a cloud account to evade defenses. A snapshot is a point-in-time copy of an existing cloud compute component such as a virtual machine (VM), virtual hard drive, or volume. An adversary may leverage permissions to create a snapshot in order to bypass restrictions that prevent access to existing compute service infrastructure, unlike in [Revert Cloud Instance](https://attack.mitre.org/techniques/T1578/004) where an adversary may revert to a snapshot to evade detection and remove evidence of their presence.

Create Cloud Instance
type: Class
subclass of: Modify Cloud Compute Infrastructure
attack-id: T1578.002
definition: An adversary may create a new instance or virtual machine (VM) within the compute service of a cloud account to evade defenses. Creating a new instance may allow an adversary to bypass firewall rules and permissions that exist on instances currently residing within an account. An adversary may [Create Snapshot](https://attack.mitre.org/techniques/T1578/001) of one or more volumes in an account, create a new instance, mount the snapshots, and then apply a less restrictive security policy to collect [Data from Local System](https://attack.mitre.org/techniques/T1005) or for [Remote Data Staging](https://attack.mitre.org/techniques/T1074/002).(Citation: Mandiant M-Trends 2020)

Delete Cloud Instance
type: Class
subclass of: Modify Cloud Compute Infrastructure
attack-id: T1578.003
definition: An adversary may delete a cloud instance after they have performed malicious activities in an attempt to evade detection and remove evidence of their presence. Deleting an instance or virtual machine can remove valuable forensic artifacts and other evidence of suspicious behavior if the instance is not recoverable.

Revert Cloud Instance
type: Class
subclass of: Modify Cloud Compute Infrastructure
attack-id: T1578.004
definition: An adversary may revert changes made to a cloud instance after they have performed malicious activities in attempt to evade detection and remove evidence of their presence. In highly virtualized environments, such as cloud-based infrastructure, this may be accomplished by restoring virtual machine (VM) or data storage snapshots through the cloud management dashboard or cloud APIs.

Modify Cloud Compute Configurations
type: Class
subclass of: Modify Cloud Compute Infrastructure
attack-id: T1578.005
definition: Adversaries may modify settings that directly affect the size, locations, and resources available to cloud compute infrastructure in order to evade defenses. These settings may include service quotas, subscription associations, tenant-wide policies, or other configurations that impact available compute. Such modifications may allow adversaries to abuse the victim’s compute resources to achieve their goals, potentially without affecting the execution of running instances and/or revealing their activities to the victim.

Cloud Infrastructure Discovery
type: Class
subclass of: Discovery Technique
attack-id: T1580
definition: An adversary may attempt to discover infrastructure and resources that are available within an infrastructure-as-a-service (IaaS) environment. This includes compute service resources such as instances, virtual machines, and snapshots as well as resources of other services including the storage and database services.

Acquire Infrastructure
type: Class
subclass of: Resource Development Technique
attack-id: T1583
definition: Adversaries may buy, lease, rent, or obtain infrastructure that can be used during targeting. A wide variety of infrastructure exists for hosting and orchestrating adversary operations. Infrastructure solutions include physical or cloud servers, domains, and third-party web services.(Citation: TrendmicroHideoutsLease) Some infrastructure providers offer free trial periods, enabling infrastructure acquisition at limited to no cost.(Citation: Free Trial PurpleUrchin) Additionally, botnets are available for rent or purchase.

Domains
type: Class
subclass of: Acquire Infrastructure
attack-id: T1583.001
definition: Adversaries may acquire domains that can be used during targeting. Domain names are the human readable names used to represent one or more IP addresses. They can be purchased or, in some cases, acquired for free.

DNS Server
type: Class
subclass of: Acquire Infrastructure
attack-id: T1583.002
definition: Adversaries may set up their own Domain Name System (DNS) servers that can be used during targeting. During post-compromise activity, adversaries may utilize DNS traffic for various tasks, including for Command and Control (ex: [Application Layer Protocol](https://attack.mitre.org/techniques/T1071)). Instead of hijacking existing DNS servers, adversaries may opt to configure and run their own DNS servers in support of operations.

Virtual Private Server
type: Class
subclass of: Acquire Infrastructure
attack-id: T1583.003
definition: Adversaries may rent Virtual Private Servers (VPSs) that can be used during targeting. There exist a variety of cloud service providers that will sell virtual machines/containers as a service. By utilizing a VPS, adversaries can make it difficult to physically tie back operations to them. The use of cloud infrastructure can also make it easier for adversaries to rapidly provision, modify, and shut down their infrastructure.

Server
type: Class
subclass of: Acquire Infrastructure
attack-id: T1583.004
definition: Adversaries may buy, lease, rent, or obtain physical servers that can be used during targeting. Use of servers allows an adversary to stage, launch, and execute an operation. During post-compromise activity, adversaries may utilize servers for various tasks, such as watering hole operations in [Drive-by Compromise](https://attack.mitre.org/techniques/T1189), enabling [Phishing](https://attack.mitre.org/techniques/T1566) operations, or facilitating [Command and Control](https://attack.mitre.org/tactics/TA0011). Instead of compromising a third-party [Server](https://attack.mitre.org/techniques/T1584/004) or renting a [Virtual Private Server](https://attack.mitre.org/techniques/T1583/003), adversaries may opt to configure and run their own servers in support of operations. Free trial periods of cloud servers may also be abused.(Citation: Free Trial PurpleUrchin)(Citation: Freejacked)

Botnet
type: Class
subclass of: Acquire Infrastructure
attack-id: T1583.005
definition: Adversaries may buy, lease, or rent a network of compromised systems that can be used during targeting. A botnet is a network of compromised systems that can be instructed to perform coordinated tasks.(Citation: Norton Botnet) Adversaries may purchase a subscription to use an existing botnet from a booter/stresser service. With a botnet at their disposal, adversaries may perform follow-on activity such as large-scale [Phishing](https://attack.mitre.org/techniques/T1566) or Distributed Denial of Service (DDoS).(Citation: Imperva DDoS for Hire)(Citation: Krebs-Anna)(Citation: Krebs-Bazaar)(Citation: Krebs-Booter)

Web Services
type: Class
subclass of: Acquire Infrastructure
attack-id: T1583.006
definition: Adversaries may register for web services that can be used during targeting. A variety of popular websites exist for adversaries to register for a web-based service that can be abused during later stages of the adversary lifecycle, such as during Command and Control ([Web Service](https://attack.mitre.org/techniques/T1102)), [Exfiltration Over Web Service](https://attack.mitre.org/techniques/T1567), or [Phishing](https://attack.mitre.org/techniques/T1566). Using common services, such as those offered by Google or Twitter, makes it easier for adversaries to hide in expected noise.(Citation: FireEye APT29) By utilizing a web service, adversaries can make it difficult to physically tie back operations to them.

Serverless
type: Class
subclass of: Acquire Infrastructure
attack-id: T1583.007
definition: Adversaries may purchase and configure serverless cloud infrastructure, such as Cloudflare Workers or AWS Lambda functions, that can be used during targeting. By utilizing serverless infrastructure, adversaries can make it more difficult to attribute infrastructure used during operations back to them.

Malvertising
type: Class
subclass of: Acquire Infrastructure
attack-id: T1583.008
definition: Adversaries may purchase online advertisements that can be abused to distribute malware to victims. Ads can be purchased to plant as well as favorably position artifacts in specific locations online, such as prominently placed within search engine results. These ads may make it more difficult for users to distinguish between actual search results and advertisements.(Citation: spamhaus-malvertising) Purchased ads may also target specific audiences using the advertising network’s capabilities, potentially further taking advantage of the trust inherently given to search engines and popular websites.

Compromise Infrastructure
type: Class
subclass of: Resource Development Technique
attack-id: T1584
definition: Adversaries may compromise third-party infrastructure that can be used during targeting. Infrastructure solutions include physical or cloud servers, domains, network devices, and third-party web and DNS services. Instead of buying, leasing, or renting infrastructure an adversary may compromise infrastructure and use it during other phases of the adversary lifecycle.(Citation: Mandiant APT1)(Citation: ICANNDomainNameHijacking)(Citation: Talos DNSpionage Nov 2018)(Citation: FireEye EPS Awakens Part 2) Additionally, adversaries may compromise numerous machines to form a botnet they can leverage.

Domains
type: Class
subclass of: Compromise Infrastructure
attack-id: T1584.001
definition: Adversaries may hijack domains and/or subdomains that can be used during targeting. Domain registration hijacking is the act of changing the registration of a domain name without the permission of the original registrant.(Citation: ICANNDomainNameHijacking) Adversaries may gain access to an email account for the person listed as the owner of the domain. The adversary can then claim that they forgot their password in order to make changes to the domain registration. Other possibilities include social engineering a domain registration help desk to gain access to an account or taking advantage of renewal process gaps.(Citation: Krebs DNS Hijack 2019)

DNS Server
type: Class
subclass of: Compromise Infrastructure
attack-id: T1584.002
definition: Adversaries may compromise third-party DNS servers that can be used during targeting. During post-compromise activity, adversaries may utilize DNS traffic for various tasks, including for Command and Control (ex: [Application Layer Protocol](https://attack.mitre.org/techniques/T1071)). Instead of setting up their own DNS servers, adversaries may compromise third-party DNS servers in support of operations.

Virtual Private Server
type: Class
subclass of: Compromise Infrastructure
attack-id: T1584.003
definition: Adversaries may compromise third-party Virtual Private Servers (VPSs) that can be used during targeting. There exist a variety of cloud service providers that will sell virtual machines/containers as a service. Adversaries may compromise VPSs purchased by third-party entities. By compromising a VPS to use as infrastructure, adversaries can make it difficult to physically tie back operations to themselves.(Citation: NSA NCSC Turla OilRig)

Server
type: Class
subclass of: Compromise Infrastructure
attack-id: T1584.004
definition: Adversaries may compromise third-party servers that can be used during targeting. Use of servers allows an adversary to stage, launch, and execute an operation. During post-compromise activity, adversaries may utilize servers for various tasks, including for Command and Control.(Citation: TrendMicro EarthLusca 2022) Instead of purchasing a [Server](https://attack.mitre.org/techniques/T1583/004) or [Virtual Private Server](https://attack.mitre.org/techniques/T1583/003), adversaries may compromise third-party servers in support of operations.

Botnet
type: Class
subclass of: Compromise Infrastructure
attack-id: T1584.005
definition: Adversaries may compromise numerous third-party systems to form a botnet that can be used during targeting. A botnet is a network of compromised systems that can be instructed to perform coordinated tasks.(Citation: Norton Botnet) Instead of purchasing/renting a botnet from a booter/stresser service, adversaries may build their own botnet by compromising numerous third-party systems.(Citation: Imperva DDoS for Hire) Adversaries may also conduct a takeover of an existing botnet, such as redirecting bots to adversary-controlled C2 servers.(Citation: Dell Dridex Oct 2015) With a botnet at their disposal, adversaries may perform follow-on activity such as large-scale [Phishing](https://attack.mitre.org/techniques/T1566) or Distributed Denial of Service (DDoS).

Web Services
type: Class
subclass of: Compromise Infrastructure
attack-id: T1584.006
definition: Adversaries may compromise access to third-party web services that can be used during targeting. A variety of popular websites exist for legitimate users to register for web-based services, such as GitHub, Twitter, Dropbox, Google, SendGrid, etc. Adversaries may try to take ownership of a legitimate user's access to a web service and use that web service as infrastructure in support of cyber operations. Such web services can be abused during later stages of the adversary lifecycle, such as during Command and Control ([Web Service](https://attack.mitre.org/techniques/T1102)), [Exfiltration Over Web Service](https://attack.mitre.org/techniques/T1567), or [Phishing](https://attack.mitre.org/techniques/T1566).(Citation: Recorded Future Turla Infra 2020) Using common services, such as those offered by Google or Twitter, makes it easier for adversaries to hide in expected noise. By utilizing a web service, particularly when access is stolen from legitimate users, adversaries can make it difficult to physically tie back operations to them. Additionally, leveraging compromised web-based email services may allow adversaries to leverage the trust associated with legitimate domains.

Serverless
type: Class
subclass of: Compromise Infrastructure
attack-id: T1584.007
definition: Adversaries may compromise serverless cloud infrastructure, such as Cloudflare Workers or AWS Lambda functions, that can be used during targeting. By utilizing serverless infrastructure, adversaries can make it more difficult to attribute infrastructure used during operations back to them.

Network Devices
type: Class
subclass of: Compromise Infrastructure
attack-id: T1584.008
definition: Adversaries may compromise third-party network devices that can be used during targeting. Network devices, such as small office/home office (SOHO) routers, may be compromised where the adversary's ultimate goal is not [Initial Access](https://attack.mitre.org/tactics/TA0001) to that environment -- instead leveraging these devices to support additional targeting.

Establish Accounts
type: Class
subclass of: Resource Development Technique
attack-id: T1585
definition: Adversaries may create and cultivate accounts with services that can be used during targeting. Adversaries can create accounts that can be used to build a persona to further operations. Persona development consists of the development of public information, presence, history and appropriate affiliations. This development could be applied to social media, website, or other publicly available information that could be referenced and scrutinized for legitimacy over the course of an operation using that persona or identity.(Citation: NEWSCASTER2014)(Citation: BlackHatRobinSage)

Social Media Accounts
type: Class
subclass of: Establish Accounts
attack-id: T1585.001
definition: Adversaries may create and cultivate social media accounts that can be used during targeting. Adversaries can create social media accounts that can be used to build a persona to further operations. Persona development consists of the development of public information, presence, history and appropriate affiliations.(Citation: NEWSCASTER2014)(Citation: BlackHatRobinSage)

Email Accounts
type: Class
subclass of: Establish Accounts
attack-id: T1585.002
definition: Adversaries may create email accounts that can be used during targeting. Adversaries can use accounts created with email providers to further their operations, such as leveraging them to conduct [Phishing for Information](https://attack.mitre.org/techniques/T1598) or [Phishing](https://attack.mitre.org/techniques/T1566).(Citation: Mandiant APT1) Establishing email accounts may also allow adversaries to abuse free services – such as trial periods – to [Acquire Infrastructure](https://attack.mitre.org/techniques/T1583) for follow-on purposes.(Citation: Free Trial PurpleUrchin)

Cloud Accounts
type: Class
subclass of: Establish Accounts
attack-id: T1585.003
definition: Adversaries may create accounts with cloud providers that can be used during targeting. Adversaries can use cloud accounts to further their operations, including leveraging cloud storage services such as Dropbox, MEGA, Microsoft OneDrive, or AWS S3 buckets for [Exfiltration to Cloud Storage](https://attack.mitre.org/techniques/T1567/002) or to [Upload Tool](https://attack.mitre.org/techniques/T1608/002)s. Cloud accounts can also be used in the acquisition of infrastructure, such as [Virtual Private Server](https://attack.mitre.org/techniques/T1583/003)s or [Serverless](https://attack.mitre.org/techniques/T1583/007) infrastructure. Establishing cloud accounts may allow adversaries to develop sophisticated capabilities without managing their own servers.(Citation: Awake Security C2 Cloud)

Compromise Accounts
type: Class
subclass of: Resource Development Technique
attack-id: T1586
definition: Adversaries may compromise accounts with services that can be used during targeting. For operations incorporating social engineering, the utilization of an online persona may be important. Rather than creating and cultivating accounts (i.e. [Establish Accounts](https://attack.mitre.org/techniques/T1585)), adversaries may compromise existing accounts. Utilizing an existing persona may engender a level of trust in a potential victim if they have a relationship, or knowledge of, the compromised persona.

Social Media Accounts
type: Class
subclass of: Compromise Accounts
attack-id: T1586.001
definition: Adversaries may compromise social media accounts that can be used during targeting. For operations incorporating social engineering, the utilization of an online persona may be important. Rather than creating and cultivating social media profiles (i.e. [Social Media Accounts](https://attack.mitre.org/techniques/T1585/001)), adversaries may compromise existing social media accounts. Utilizing an existing persona may engender a level of trust in a potential victim if they have a relationship, or knowledge of, the compromised persona.

Email Accounts
type: Class
subclass of: Compromise Accounts
attack-id: T1586.002
definition: Adversaries may compromise email accounts that can be used during targeting. Adversaries can use compromised email accounts to further their operations, such as leveraging them to conduct [Phishing for Information](https://attack.mitre.org/techniques/T1598), [Phishing](https://attack.mitre.org/techniques/T1566), or large-scale spam email campaigns. Utilizing an existing persona with a compromised email account may engender a level of trust in a potential victim if they have a relationship with, or knowledge of, the compromised persona. Compromised email accounts can also be used in the acquisition of infrastructure (ex: [Domains](https://attack.mitre.org/techniques/T1583/001)).

Cloud Accounts
type: Class
subclass of: Compromise Accounts
attack-id: T1586.003
definition: Adversaries may compromise cloud accounts that can be used during targeting. Adversaries can use compromised cloud accounts to further their operations, including leveraging cloud storage services such as Dropbox, Microsoft OneDrive, or AWS S3 buckets for [Exfiltration to Cloud Storage](https://attack.mitre.org/techniques/T1567/002) or to [Upload Tool](https://attack.mitre.org/techniques/T1608/002)s. Cloud accounts can also be used in the acquisition of infrastructure, such as [Virtual Private Server](https://attack.mitre.org/techniques/T1583/003)s or [Serverless](https://attack.mitre.org/techniques/T1583/007) infrastructure. Compromising cloud accounts may allow adversaries to develop sophisticated capabilities without managing their own servers.(Citation: Awake Security C2 Cloud)

Develop Capabilities
type: Class
subclass of: Resource Development Technique
attack-id: T1587
definition: Adversaries may build capabilities that can be used during targeting. Rather than purchasing, freely downloading, or stealing capabilities, adversaries may develop their own capabilities in-house. This is the process of identifying development requirements and building solutions such as malware, exploits, and self-signed certificates. Adversaries may develop capabilities to support their operations throughout numerous phases of the adversary lifecycle.(Citation: Mandiant APT1)(Citation: Kaspersky Sofacy)(Citation: Bitdefender StrongPity June 2020)(Citation: Talos Promethium June 2020)

Malware
type: Class
subclass of: Develop Capabilities
attack-id: T1587.001
definition: Adversaries may develop malware and malware components that can be used during targeting. Building malicious software can include the development of payloads, droppers, post-compromise tools, backdoors (including backdoored images), packers, C2 protocols, and the creation of infected removable media. Adversaries may develop malware to support their operations, creating a means for maintaining control of remote machines, evading defenses, and executing post-compromise behaviors.(Citation: Mandiant APT1)(Citation: Kaspersky Sofacy)(Citation: ActiveMalwareEnergy)(Citation: FBI Flash FIN7 USB)

Code Signing Certificates
type: Class
subclass of: Develop Capabilities
attack-id: T1587.002
definition: Adversaries may create self-signed code signing certificates that can be used during targeting. Code signing is the process of digitally signing executables and scripts to confirm the software author and guarantee that the code has not been altered or corrupted. Code signing provides a level of authenticity for a program from the developer and a guarantee that the program has not been tampered with.(Citation: Wikipedia Code Signing) Users and/or security tools may trust a signed piece of code more than an unsigned piece of code even if they don't know who issued the certificate or who the author is.

Digital Certificates
type: Class
subclass of: Develop Capabilities
attack-id: T1587.003
definition: Adversaries may create self-signed SSL/TLS certificates that can be used during targeting. SSL/TLS certificates are designed to instill trust. They include information about the key, information about its owner's identity, and the digital signature of an entity that has verified the certificate's contents are correct. If the signature is valid, and the person examining the certificate trusts the signer, then they know they can use that key to communicate with its owner. In the case of self-signing, digital certificates will lack the element of trust associated with the signature of a third-party certificate authority (CA).

Exploits
type: Class
subclass of: Develop Capabilities
attack-id: T1587.004
definition: Adversaries may develop exploits that can be used during targeting. An exploit takes advantage of a bug or vulnerability in order to cause unintended or unanticipated behavior to occur on computer hardware or software. Rather than finding/modifying exploits from online or purchasing them from exploit vendors, an adversary may develop their own exploits.(Citation: NYTStuxnet) Adversaries may use information acquired via [Vulnerabilities](https://attack.mitre.org/techniques/T1588/006) to focus exploit development efforts. As part of the exploit development process, adversaries may uncover exploitable vulnerabilities through methods such as fuzzing and patch analysis.(Citation: Irongeek Sims BSides 2017)

Obtain Capabilities
type: Class
subclass of: Resource Development Technique
attack-id: T1588
definition: Adversaries may buy and/or steal capabilities that can be used during targeting. Rather than developing their own capabilities in-house, adversaries may purchase, freely download, or steal them. Activities may include the acquisition of malware, software (including licenses), exploits, certificates, and information relating to vulnerabilities. Adversaries may obtain capabilities to support their operations throughout numerous phases of the adversary lifecycle.

Malware
type: Class
subclass of: Obtain Capabilities
attack-id: T1588.001
definition: Adversaries may buy, steal, or download malware that can be used during targeting. Malicious software can include payloads, droppers, post-compromise tools, backdoors, packers, and C2 protocols. Adversaries may acquire malware to support their operations, obtaining a means for maintaining control of remote machines, evading defenses, and executing post-compromise behaviors.

Tool
type: Class
subclass of: Obtain Capabilities
attack-id: T1588.002
definition: Adversaries may buy, steal, or download software tools that can be used during targeting. Tools can be open or closed source, free or commercial. A tool can be used for malicious purposes by an adversary, but (unlike malware) were not intended to be used for those purposes (ex: [PsExec](https://attack.mitre.org/software/S0029)). Tool acquisition can involve the procurement of commercial software licenses, including for red teaming tools such as [Cobalt Strike](https://attack.mitre.org/software/S0154). Commercial software may be obtained through purchase, stealing licenses (or licensed copies of the software), or cracking trial versions.(Citation: Recorded Future Beacon 2019)

Code Signing Certificates
type: Class
subclass of: Obtain Capabilities
attack-id: T1588.003
definition: Adversaries may buy and/or steal code signing certificates that can be used during targeting. Code signing is the process of digitally signing executables and scripts to confirm the software author and guarantee that the code has not been altered or corrupted. Code signing provides a level of authenticity for a program from the developer and a guarantee that the program has not been tampered with.(Citation: Wikipedia Code Signing) Users and/or security tools may trust a signed piece of code more than an unsigned piece of code even if they don't know who issued the certificate or who the author is.

Digital Certificates
type: Class
subclass of: Obtain Capabilities
attack-id: T1588.004
definition: Adversaries may buy and/or steal SSL/TLS certificates that can be used during targeting. SSL/TLS certificates are designed to instill trust. They include information about the key, information about its owner's identity, and the digital signature of an entity that has verified the certificate's contents are correct. If the signature is valid, and the person examining the certificate trusts the signer, then they know they can use that key to communicate with its owner.

Exploits
type: Class
subclass of: Obtain Capabilities
attack-id: T1588.005
definition: Adversaries may buy, steal, or download exploits that can be used during targeting. An exploit takes advantage of a bug or vulnerability in order to cause unintended or unanticipated behavior to occur on computer hardware or software. Rather than developing their own exploits, an adversary may find/modify exploits from online or purchase them from exploit vendors.(Citation: Exploit Database)(Citation: TempertonDarkHotel)(Citation: NationsBuying)

Vulnerabilities
type: Class
subclass of: Obtain Capabilities
attack-id: T1588.006
definition: Adversaries may acquire information about vulnerabilities that can be used during targeting. A vulnerability is a weakness in computer hardware or software that can, potentially, be exploited by an adversary to cause unintended or unanticipated behavior to occur. Adversaries may find vulnerability information by searching open databases or gaining access to closed vulnerability databases.(Citation: National Vulnerability Database)

Artificial Intelligence
type: Class
subclass of: Obtain Capabilities
attack-id: T1588.007
definition: Adversaries may obtain access to generative artificial intelligence tools, such as large language models (LLMs), to aid various techniques during targeting. These tools may be used to inform, bolster, and enable a variety of malicious tasks including conducting [Reconnaissance](https://attack.mitre.org/tactics/TA0043), creating basic scripts, assisting social engineering, and even developing payloads.(Citation: MSFT-AI)

Gather Victim Identity Information
type: Class
subclass of: Reconnaissance Technique
attack-id: T1589
definition: Adversaries may gather information about the victim's identity that can be used during targeting. Information about identities may include a variety of details, including personal data (ex: employee names, email addresses, security question responses, etc.) as well as sensitive details such as credentials or multi-factor authentication (MFA) configurations.

Credentials
type: Class
subclass of: Gather Victim Identity Information
attack-id: T1589.001
definition: Adversaries may gather credentials that can be used during targeting. Account credentials gathered by adversaries may be those directly associated with the target victim organization or attempt to take advantage of the tendency for users to use the same passwords across personal and business accounts.

Email Addresses
type: Class
subclass of: Gather Victim Identity Information
attack-id: T1589.002
definition: Adversaries may gather email addresses that can be used during targeting. Even if internal instances exist, organizations may have public-facing email infrastructure and addresses for employees.

Employee Names
type: Class
subclass of: Gather Victim Identity Information
attack-id: T1589.003
definition: Adversaries may gather employee names that can be used during targeting. Employee names be used to derive email addresses as well as to help guide other reconnaissance efforts and/or craft more-believable lures.

Gather Victim Network Information
type: Class
subclass of: Reconnaissance Technique
attack-id: T1590
definition: Adversaries may gather information about the victim's networks that can be used during targeting. Information about networks may include a variety of details, including administrative data (ex: IP ranges, domain names, etc.) as well as specifics regarding its topology and operations.

Domain Properties
type: Class
subclass of: Gather Victim Network Information
attack-id: T1590.001
definition: Adversaries may gather information about the victim's network domain(s) that can be used during targeting. Information about domains and their properties may include a variety of details, including what domain(s) the victim owns as well as administrative data (ex: name, registrar, etc.) and more directly actionable information such as contacts (email addresses and phone numbers), business addresses, and name servers.

DNS
type: Class
subclass of: Gather Victim Network Information
attack-id: T1590.002
definition: Adversaries may gather information about the victim's DNS that can be used during targeting. DNS information may include a variety of details, including registered name servers as well as records that outline addressing for a target’s subdomains, mail servers, and other hosts. DNS, MX, TXT, and SPF records may also reveal the use of third party cloud and SaaS providers, such as Office 365, G Suite, Salesforce, or Zendesk.(Citation: Sean Metcalf Twitter DNS Records)

Network Trust Dependencies
type: Class
subclass of: Gather Victim Network Information
attack-id: T1590.003
definition: Adversaries may gather information about the victim's network trust dependencies that can be used during targeting. Information about network trusts may include a variety of details, including second or third-party organizations/domains (ex: managed service providers, contractors, etc.) that have connected (and potentially elevated) network access.

Network Topology
type: Class
subclass of: Gather Victim Network Information
attack-id: T1590.004
definition: Adversaries may gather information about the victim's network topology that can be used during targeting. Information about network topologies may include a variety of details, including the physical and/or logical arrangement of both external-facing and internal network environments. This information may also include specifics regarding network devices (gateways, routers, etc.) and other infrastructure.

IP Addresses
type: Class
subclass of: Gather Victim Network Information
attack-id: T1590.005
definition: Adversaries may gather the victim's IP addresses that can be used during targeting. Public IP addresses may be allocated to organizations by block, or a range of sequential addresses. Information about assigned IP addresses may include a variety of details, such as which IP addresses are in use. IP addresses may also enable an adversary to derive other details about a victim, such as organizational size, physical location(s), Internet service provider, and or where/how their publicly-facing infrastructure is hosted.

Network Security Appliances
type: Class
subclass of: Gather Victim Network Information
attack-id: T1590.006
definition: Adversaries may gather information about the victim's network security appliances that can be used during targeting. Information about network security appliances may include a variety of details, such as the existence and specifics of deployed firewalls, content filters, and proxies/bastion hosts. Adversaries may also target information about victim network-based intrusion detection systems (NIDS) or other appliances related to defensive cybersecurity operations.

Gather Victim Org Information
type: Class
subclass of: Reconnaissance Technique
attack-id: T1591
definition: Adversaries may gather information about the victim's organization that can be used during targeting. Information about an organization may include a variety of details, including the names of divisions/departments, specifics of business operations, as well as the roles and responsibilities of key employees.

Determine Physical Locations
type: Class
subclass of: Gather Victim Org Information
attack-id: T1591.001
definition: Adversaries may gather the victim's physical location(s) that can be used during targeting. Information about physical locations of a target organization may include a variety of details, including where key resources and infrastructure are housed. Physical locations may also indicate what legal jurisdiction and/or authorities the victim operates within.

Business Relationships
type: Class
subclass of: Gather Victim Org Information
attack-id: T1591.002
definition: Adversaries may gather information about the victim's business relationships that can be used during targeting. Information about an organization’s business relationships may include a variety of details, including second or third-party organizations/domains (ex: managed service providers, contractors, etc.) that have connected (and potentially elevated) network access. This information may also reveal supply chains and shipment paths for the victim’s hardware and software resources.

Identify Business Tempo
type: Class
subclass of: Gather Victim Org Information
attack-id: T1591.003
definition: Adversaries may gather information about the victim's business tempo that can be used during targeting. Information about an organization’s business tempo may include a variety of details, including operational hours/days of the week. This information may also reveal times/dates of purchases and shipments of the victim’s hardware and software resources.

Identify Roles
type: Class
subclass of: Gather Victim Org Information
attack-id: T1591.004
definition: Adversaries may gather information about identities and roles within the victim organization that can be used during targeting. Information about business roles may reveal a variety of targetable details, including identifiable information for key personnel as well as what data/resources they have access to.

Gather Victim Host Information
type: Class
subclass of: Reconnaissance Technique
attack-id: T1592
definition: Adversaries may gather information about the victim's hosts that can be used during targeting. Information about hosts may include a variety of details, including administrative data (ex: name, assigned IP, functionality, etc.) as well as specifics regarding its configuration (ex: operating system, language, etc.).

Hardware
type: Class
subclass of: Gather Victim Host Information
attack-id: T1592.001
definition: Adversaries may gather information about the victim's host hardware that can be used during targeting. Information about hardware infrastructure may include a variety of details such as types and versions on specific hosts, as well as the presence of additional components that might be indicative of added defensive protections (ex: card/biometric readers, dedicated encryption hardware, etc.).

Software
type: Class
subclass of: Gather Victim Host Information
attack-id: T1592.002
definition: Adversaries may gather information about the victim's host software that can be used during targeting. Information about installed software may include a variety of details such as types and versions on specific hosts, as well as the presence of additional components that might be indicative of added defensive protections (ex: antivirus, SIEMs, etc.).

Firmware
type: Class
subclass of: Gather Victim Host Information
attack-id: T1592.003
definition: Adversaries may gather information about the victim's host firmware that can be used during targeting. Information about host firmware may include a variety of details such as type and versions on specific hosts, which may be used to infer more information about hosts in the environment (ex: configuration, purpose, age/patch level, etc.).

Client Configurations
type: Class
subclass of: Gather Victim Host Information
attack-id: T1592.004
definition: Adversaries may gather information about the victim's client configurations that can be used during targeting. Information about client configurations may include a variety of details and settings, including operating system/version, virtualization, architecture (ex: 32 or 64 bit), language, and/or time zone.

Search Open Websites/Domains
type: Class
subclass of: Reconnaissance Technique
attack-id: T1593
definition: Adversaries may search freely available websites and/or domains for information about victims that can be used during targeting. Information about victims may be available in various online sites, such as social media, new sites, or those hosting information about business operations such as hiring or requested/rewarded contracts.(Citation: Cyware Social Media)(Citation: SecurityTrails Google Hacking)(Citation: ExploitDB GoogleHacking)

Social Media
type: Class
subclass of: Search Open Websites/Domains
attack-id: T1593.001
definition: Adversaries may search social media for information about victims that can be used during targeting. Social media sites may contain various information about a victim organization, such as business announcements as well as information about the roles, locations, and interests of staff.

Search Engines
type: Class
subclass of: Search Open Websites/Domains
attack-id: T1593.002
definition: Adversaries may use search engines to collect information about victims that can be used during targeting. Search engine services typical crawl online sites to index context and may provide users with specialized syntax to search for specific keywords or specific types of content (i.e. filetypes).(Citation: SecurityTrails Google Hacking)(Citation: ExploitDB GoogleHacking)

Code Repositories
type: Class
subclass of: Search Open Websites/Domains
attack-id: T1593.003
definition: Adversaries may search public code repositories for information about victims that can be used during targeting. Victims may store code in repositories on various third-party websites such as GitHub, GitLab, SourceForge, and BitBucket. Users typically interact with code repositories through a web application or command-line utilities such as git.

Search Victim-Owned Websites
type: Class
subclass of: Reconnaissance Technique
attack-id: T1594
definition: Adversaries may search websites owned by the victim for information that can be used during targeting. Victim-owned websites may contain a variety of details, including names of departments/divisions, physical locations, and data about key employees such as names, roles, and contact info (ex: [Email Addresses](https://attack.mitre.org/techniques/T1589/002)). These sites may also have details highlighting business operations and relationships.(Citation: Comparitech Leak)

Active Scanning
type: Class
subclass of: Reconnaissance Technique
attack-id: T1595
definition: Adversaries may execute active reconnaissance scans to gather information that can be used during targeting. Active scans are those where the adversary probes victim infrastructure via network traffic, as opposed to other forms of reconnaissance that do not involve direct interaction.

Scanning IP Blocks
type: Class
subclass of: Active Scanning
attack-id: T1595.001
definition: Adversaries may scan victim IP blocks to gather information that can be used during targeting. Public IP addresses may be allocated to organizations by block, or a range of sequential addresses.

Vulnerability Scanning
type: Class
subclass of: Active Scanning
attack-id: T1595.002
definition: Adversaries may scan victims for vulnerabilities that can be used during targeting. Vulnerability scans typically check if the configuration of a target host/application (ex: software and version) potentially aligns with the target of a specific exploit the adversary may seek to use.

Wordlist Scanning
type: Class
subclass of: Active Scanning
attack-id: T1595.003
definition: Adversaries may iteratively probe infrastructure using brute-forcing and crawling techniques. While this technique employs similar methods to [Brute Force](https://attack.mitre.org/techniques/T1110), its goal is the identification of content and infrastructure rather than the discovery of valid credentials. Wordlists used in these scans may contain generic, commonly used names and file extensions or terms specific to a particular software. Adversaries may also create custom, target-specific wordlists using data gathered from other Reconnaissance techniques (ex: [Gather Victim Org Information](https://attack.mitre.org/techniques/T1591), or [Search Victim-Owned Websites](https://attack.mitre.org/techniques/T1594)).

Search Open Technical Databases
type: Class
subclass of: Reconnaissance Technique
attack-id: T1596
definition: Adversaries may search freely available technical databases for information about victims that can be used during targeting. Information about victims may be available in online databases and repositories, such as registrations of domains/certificates as well as public collections of network data/artifacts gathered from traffic and/or scans.(Citation: WHOIS)(Citation: DNS Dumpster)(Citation: Circl Passive DNS)(Citation: Medium SSL Cert)(Citation: SSLShopper Lookup)(Citation: DigitalShadows CDN)(Citation: Shodan)

DNS/Passive DNS
type: Class
subclass of: Search Open Technical Databases
attack-id: T1596.001
definition: Adversaries may search DNS data for information about victims that can be used during targeting. DNS information may include a variety of details, including registered name servers as well as records that outline addressing for a target’s subdomains, mail servers, and other hosts.

WHOIS
type: Class
subclass of: Search Open Technical Databases
attack-id: T1596.002
definition: Adversaries may search public WHOIS data for information about victims that can be used during targeting. WHOIS data is stored by regional Internet registries (RIR) responsible for allocating and assigning Internet resources such as domain names. Anyone can query WHOIS servers for information about a registered domain, such as assigned IP blocks, contact information, and DNS nameservers.(Citation: WHOIS)

Digital Certificates
type: Class
subclass of: Search Open Technical Databases
attack-id: T1596.003
definition: Adversaries may search public digital certificate data for information about victims that can be used during targeting. Digital certificates are issued by a certificate authority (CA) in order to cryptographically verify the origin of signed content. These certificates, such as those used for encrypted web traffic (HTTPS SSL/TLS communications), contain information about the registered organization such as name and location.

CDNs
type: Class
subclass of: Search Open Technical Databases
attack-id: T1596.004
definition: Adversaries may search content delivery network (CDN) data about victims that can be used during targeting. CDNs allow an organization to host content from a distributed, load balanced array of servers. CDNs may also allow organizations to customize content delivery based on the requestor’s geographical region.

Scan Databases
type: Class
subclass of: Search Open Technical Databases
attack-id: T1596.005
definition: Adversaries may search within public scan databases for information about victims that can be used during targeting. Various online services continuously publish the results of Internet scans/surveys, often harvesting information such as active IP addresses, hostnames, open ports, certificates, and even server banners.(Citation: Shodan)

Search Closed Sources
type: Class
subclass of: Reconnaissance Technique
attack-id: T1597
definition: Adversaries may search and gather information about victims from closed sources that can be used during targeting. Information about victims may be available for purchase from reputable private sources and databases, such as paid subscriptions to feeds of technical/threat intelligence data.(Citation: D3Secutrity CTI Feeds) Adversaries may also purchase information from less-reputable sources such as dark web or cybercrime blackmarkets.(Citation: ZDNET Selling Data)

Threat Intel Vendors
type: Class
subclass of: Search Closed Sources
attack-id: T1597.001
definition: Adversaries may search private data from threat intelligence vendors for information that can be used during targeting. Threat intelligence vendors may offer paid feeds or portals that offer more data than what is publicly reported. Although sensitive details (such as customer names and other identifiers) may be redacted, this information may contain trends regarding breaches such as target industries, attribution claims, and successful TTPs/countermeasures.(Citation: D3Secutrity CTI Feeds)

Purchase Technical Data
type: Class
subclass of: Search Closed Sources
attack-id: T1597.002
definition: Adversaries may purchase technical information about victims that can be used during targeting. Information about victims may be available for purchase within reputable private sources and databases, such as paid subscriptions to feeds of scan databases or other data aggregation services. Adversaries may also purchase information from less-reputable sources such as dark web or cybercrime blackmarkets.

Phishing for Information
type: Class
subclass of: Reconnaissance Technique
attack-id: T1598
definition: Adversaries may send phishing messages to elicit sensitive information that can be used during targeting. Phishing for information is an attempt to trick targets into divulging information, frequently credentials or other actionable information. Phishing for information is different from [Phishing](https://attack.mitre.org/techniques/T1566) in that the objective is gathering data from the victim rather than executing malicious code.

Spearphishing Service
type: Class
subclass of: Phishing for Information
attack-id: T1598.001
definition: Adversaries may send spearphishing messages via third-party services to elicit sensitive information that can be used during targeting. Spearphishing for information is an attempt to trick targets into divulging information, frequently credentials or other actionable information. Spearphishing for information frequently involves social engineering techniques, such as posing as a source with a reason to collect information (ex: [Establish Accounts](https://attack.mitre.org/techniques/T1585) or [Compromise Accounts](https://attack.mitre.org/techniques/T1586)) and/or sending multiple, seemingly urgent messages.

Spearphishing Attachment
type: Class
subclass of: Phishing for Information
attack-id: T1598.002
definition: Adversaries may send spearphishing messages with a malicious attachment to elicit sensitive information that can be used during targeting. Spearphishing for information is an attempt to trick targets into divulging information, frequently credentials or other actionable information. Spearphishing for information frequently involves social engineering techniques, such as posing as a source with a reason to collect information (ex: [Establish Accounts](https://attack.mitre.org/techniques/T1585) or [Compromise Accounts](https://attack.mitre.org/techniques/T1586)) and/or sending multiple, seemingly urgent messages.

Spearphishing Link
type: Class
subclass of: Phishing for Information
attack-id: T1598.003
definition: Adversaries may send spearphishing messages with a malicious link to elicit sensitive information that can be used during targeting. Spearphishing for information is an attempt to trick targets into divulging information, frequently credentials or other actionable information. Spearphishing for information frequently involves social engineering techniques, such as posing as a source with a reason to collect information (ex: [Establish Accounts](https://attack.mitre.org/techniques/T1585) or [Compromise Accounts](https://attack.mitre.org/techniques/T1586)) and/or sending multiple, seemingly urgent messages.

Spearphishing Voice
type: Class
subclass of: Phishing for Information
attack-id: T1598.004
definition: Adversaries may use voice communications to elicit sensitive information that can be used during targeting. Spearphishing for information is an attempt to trick targets into divulging information, frequently credentials or other actionable information. Spearphishing for information frequently involves social engineering techniques, such as posing as a source with a reason to collect information (ex: [Impersonation](https://attack.mitre.org/techniques/T1656)) and/or creating a sense of urgency or alarm for the recipient.

Network Boundary Bridging
type: Class
subclass of: Defense Evasion Technique
attack-id: T1599
definition: Adversaries may bridge network boundaries by compromising perimeter network devices or internal devices responsible for network segmentation. Breaching these devices may enable an adversary to bypass restrictions on traffic routing that otherwise separate trusted and untrusted networks.

Network Address Translation Traversal
type: Class
subclass of: Network Boundary Bridging
attack-id: T1599.001
definition: Adversaries may bridge network boundaries by modifying a network device’s Network Address Translation (NAT) configuration. Malicious modifications to NAT may enable an adversary to bypass restrictions on traffic routing that otherwise separate trusted and untrusted networks.

Weaken Encryption
type: Class
subclass of: Defense Evasion Technique
attack-id: T1600
definition: Adversaries may compromise a network device’s encryption capability in order to bypass encryption that would otherwise protect data communications. (Citation: Cisco Synful Knock Evolution)

Reduce Key Space
type: Class
subclass of: Weaken Encryption
attack-id: T1600.001
definition: Adversaries may reduce the level of effort required to decrypt data transmitted over the network by reducing the cipher strength of encrypted communications.(Citation: Cisco Synful Knock Evolution)

Disable Crypto Hardware
type: Class
subclass of: Weaken Encryption
attack-id: T1600.002
definition: Adversaries disable a network device’s dedicated hardware encryption, which may enable them to leverage weaknesses in software encryption in order to reduce the effort involved in collecting, manipulating, and exfiltrating transmitted data.

Modify System Image
type: Class
subclass of: Defense Evasion Technique
attack-id: T1601
definition: Adversaries may make changes to the operating system of embedded network devices to weaken defenses and provide new capabilities for themselves. On such devices, the operating systems are typically monolithic and most of the device functionality and capabilities are contained within a single file.

Patch System Image
type: Class
subclass of: Modify System Image
attack-id: T1601.001
definition: Adversaries may modify the operating system of a network device to introduce new capabilities or weaken existing defenses.(Citation: Killing the myth of Cisco IOS rootkits) (Citation: Killing IOS diversity myth) (Citation: Cisco IOS Shellcode) (Citation: Cisco IOS Forensics Developments) (Citation: Juniper Netscreen of the Dead) Some network devices are built with a monolithic architecture, where the entire operating system and most of the functionality of the device is contained within a single file. Adversaries may change this file in storage, to be loaded in a future boot, or in memory during runtime.

Downgrade System Image
type: Class
subclass of: Modify System Image
attack-id: T1601.002
definition: Adversaries may install an older version of the operating system of a network device to weaken security. Older operating system versions on network devices often have weaker encryption ciphers and, in general, fewer/less updated defensive features. (Citation: Cisco Synful Knock Evolution)

Data from Configuration Repository
type: Class
subclass of: Collection Technique
attack-id: T1602
definition: Adversaries may collect data related to managed devices from configuration repositories. Configuration repositories are used by management systems in order to configure, manage, and control data on remote systems. Configuration repositories may also facilitate remote access and administration of devices.

SNMP (MIB Dump)
type: Class
subclass of: Data from Configuration Repository
attack-id: T1602.001
definition: Adversaries may target the Management Information Base (MIB) to collect and/or mine valuable information in a network managed using Simple Network Management Protocol (SNMP).

Network Device Configuration Dump
type: Class
subclass of: Data from Configuration Repository
attack-id: T1602.002
definition: Adversaries may access network configuration files to collect sensitive data about the device and the network. The network configuration is a file containing parameters that determine the operation of the device. The device typically stores an in-memory copy of the configuration while operating, and a separate configuration on non-volatile storage to load after device reset. Adversaries can inspect the configuration files to reveal information about the target network and its layout, the network device and its software, or identifying legitimate accounts and credentials for later use.

Forge Web Credentials
type: Class
subclass of: Credential Access Technique
attack-id: T1606
definition: Adversaries may forge credential materials that can be used to gain access to web applications or Internet services. Web applications and services (hosted in cloud SaaS environments or on-premise servers) often use session cookies, tokens, or other materials to authenticate and authorize user access.

Web Cookies
type: Class
subclass of: Forge Web Credentials
attack-id: T1606.001
definition: Adversaries may forge web cookies that can be used to gain access to web applications or Internet services. Web applications and services (hosted in cloud SaaS environments or on-premise servers) often use session cookies to authenticate and authorize user access.

SAML Tokens
type: Class
subclass of: Forge Web Credentials
attack-id: T1606.002
definition: An adversary may forge SAML tokens with any permissions claims and lifetimes if they possess a valid SAML token-signing certificate.(Citation: Microsoft SolarWinds Steps) The default lifetime of a SAML token is one hour, but the validity period can be specified in the NotOnOrAfter value of the conditions ... element in a token. This value can be changed using the AccessTokenLifetime in a LifetimeTokenPolicy.(Citation: Microsoft SAML Token Lifetimes) Forged SAML tokens enable adversaries to authenticate across services that use SAML 2.0 as an SSO (single sign-on) mechanism.(Citation: Cyberark Golden SAML)

Stage Capabilities
type: Class
subclass of: Resource Development Technique
attack-id: T1608
definition: Adversaries may upload, install, or otherwise set up capabilities that can be used during targeting. To support their operations, an adversary may need to take capabilities they developed ([Develop Capabilities](https://attack.mitre.org/techniques/T1587)) or obtained ([Obtain Capabilities](https://attack.mitre.org/techniques/T1588)) and stage them on infrastructure under their control. These capabilities may be staged on infrastructure that was previously purchased/rented by the adversary ([Acquire Infrastructure](https://attack.mitre.org/techniques/T1583)) or was otherwise compromised by them ([Compromise Infrastructure](https://attack.mitre.org/techniques/T1584)). Capabilities may also be staged on web services, such as GitHub or Pastebin, or on Platform-as-a-Service (PaaS) offerings that enable users to easily provision applications.(Citation: Volexity Ocean Lotus November 2020)(Citation: Dragos Heroku Watering Hole)(Citation: Malwarebytes Heroku Skimmers)(Citation: Netskope GCP Redirection)(Citation: Netskope Cloud Phishing)

Upload Malware
type: Class
subclass of: Stage Capabilities
attack-id: T1608.001
definition: Adversaries may upload malware to third-party or adversary controlled infrastructure to make it accessible during targeting. Malicious software can include payloads, droppers, post-compromise tools, backdoors, and a variety of other malicious content. Adversaries may upload malware to support their operations, such as making a payload available to a victim network to enable [Ingress Tool Transfer](https://attack.mitre.org/techniques/T1105) by placing it on an Internet accessible web server.

Upload Tool
type: Class
subclass of: Stage Capabilities
attack-id: T1608.002
definition: Adversaries may upload tools to third-party or adversary controlled infrastructure to make it accessible during targeting. Tools can be open or closed source, free or commercial. Tools can be used for malicious purposes by an adversary, but (unlike malware) were not intended to be used for those purposes (ex: [PsExec](https://attack.mitre.org/software/S0029)). Adversaries may upload tools to support their operations, such as making a tool available to a victim network to enable [Ingress Tool Transfer](https://attack.mitre.org/techniques/T1105) by placing it on an Internet accessible web server.

Install Digital Certificate
type: Class
subclass of: Stage Capabilities
attack-id: T1608.003
definition: Adversaries may install SSL/TLS certificates that can be used during targeting. SSL/TLS certificates are files that can be installed on servers to enable secure communications between systems. Digital certificates include information about the key, information about its owner's identity, and the digital signature of an entity that has verified the certificate's contents are correct. If the signature is valid, and the person examining the certificate trusts the signer, then they know they can use that key to communicate securely with its owner. Certificates can be uploaded to a server, then the server can be configured to use the certificate to enable encrypted communication with it.(Citation: DigiCert Install SSL Cert)

Drive-by Target
type: Class
subclass of: Stage Capabilities
attack-id: T1608.004
definition: Adversaries may prepare an operational environment to infect systems that visit a website over the normal course of browsing. Endpoint systems may be compromised through browsing to adversary controlled sites, as in [Drive-by Compromise](https://attack.mitre.org/techniques/T1189). In such cases, the user's web browser is typically targeted for exploitation (often not requiring any extra user interaction once landing on the site), but adversaries may also set up websites for non-exploitation behavior such as [Application Access Token](https://attack.mitre.org/techniques/T1550/001). Prior to [Drive-by Compromise](https://attack.mitre.org/techniques/T1189), adversaries must stage resources needed to deliver that exploit to users who browse to an adversary controlled site. Drive-by content can be staged on adversary controlled infrastructure that has been acquired ([Acquire Infrastructure](https://attack.mitre.org/techniques/T1583)) or previously compromised ([Compromise Infrastructure](https://attack.mitre.org/techniques/T1584)).

Link Target
type: Class
subclass of: Stage Capabilities
attack-id: T1608.005
definition: Adversaries may put in place resources that are referenced by a link that can be used during targeting. An adversary may rely upon a user clicking a malicious link in order to divulge information (including credentials) or to gain execution, as in [Malicious Link](https://attack.mitre.org/techniques/T1204/001). Links can be used for spearphishing, such as sending an email accompanied by social engineering text to coax the user to actively click or copy and paste a URL into a browser. Prior to a phish for information (as in [Spearphishing Link](https://attack.mitre.org/techniques/T1598/003)) or a phish to gain initial access to a system (as in [Spearphishing Link](https://attack.mitre.org/techniques/T1566/002)), an adversary must set up the resources for a link target for the spearphishing link.

SEO Poisoning
type: Class
subclass of: Stage Capabilities
attack-id: T1608.006
definition: Adversaries may poison mechanisms that influence search engine optimization (SEO) to further lure staged capabilities towards potential victims. Search engines typically display results to users based on purchased ads as well as the site’s ranking/score/reputation calculated by their web crawlers and algorithms.(Citation: Atlas SEO)(Citation: MalwareBytes SEO)

Container Administration Command
type: Class
subclass of: Execution Technique
attack-id: T1609
definition: Adversaries may abuse a container administration service to execute commands within a container. A container administration service such as the Docker daemon, the Kubernetes API server, or the kubelet may allow remote management of containers within an environment.(Citation: Docker Daemon CLI)(Citation: Kubernetes API)(Citation: Kubernetes Kubelet)

Deploy Container
type: Class
subclass of: Defense Evasion Technique
subclass of: Execution Technique
attack-id: T1610
definition: Adversaries may deploy a container into an environment to facilitate execution or evade defenses. In some cases, adversaries may deploy a new container to execute processes associated with a particular image or deployment, such as processes that execute or download malware. In others, an adversary may deploy a new container configured without network rules, user limitations, etc. to bypass existing defenses within the environment. In Kubernetes environments, an adversary may attempt to deploy a privileged or vulnerable container into a specific node in order to [Escape to Host](https://attack.mitre.org/techniques/T1611) and access other containers running on the node. (Citation: AppSecco Kubernetes Namespace Breakout 2020)

Escape to Host
type: Class
subclass of: Privilege Escalation Technique
attack-id: T1611
definition: Adversaries may break out of a container to gain access to the underlying host. This can allow an adversary access to other containerized resources from the host level or to the host itself. In principle, containerized resources should provide a clear separation of application functionality and be isolated from the host environment.(Citation: Docker Overview)

Build Image on Host
type: Class
subclass of: Defense Evasion Technique
attack-id: T1612
definition: Adversaries may build a container image directly on a host to bypass defenses that monitor for the retrieval of malicious images from a public registry. A remote build request may be sent to the Docker API that includes a Dockerfile that pulls a vanilla base image, such as alpine, from a public or local registry and then builds a custom image upon it.(Citation: Docker Build Image)

Container and Resource Discovery
type: Class
subclass of: Discovery Technique
attack-id: T1613
definition: Adversaries may attempt to discover containers and other resources that are available within a containers environment. Other resources may include images, deployments, pods, nodes, and other information such as the status of a cluster.

System Location Discovery
type: Class
subclass of: Discovery Technique
subclass of: Restriction
  on property: accesses
  some values from: Configuration Resource
type: NamedIndividual
accesses: Configuration Resource
attack-id: T1614

System Language Discovery
type: Class
subclass of: System Location Discovery
subclass of: Restriction
  on property: queries
  some values from: System Configuration Database
type: NamedIndividual
queries: System Configuration Database
attack-id: T1614.001
definition: Adversaries may attempt to gather information about the system language of a victim in order to infer the geographical location of that host. This information may be used to shape follow-on behaviors, including whether the adversary infects the target and/or attempts specific actions. This decision may be employed by malware developers and operators to reduce their risk of attracting the attention of specific law enforcement agencies or prosecution/scrutiny from other entities.(Citation: Malware System Language Check)

Group Policy Discovery
type: Class
subclass of: Discovery Technique
subclass of: Restriction
  on property: reads
  some values from: Group Policy
type: NamedIndividual
reads: Group Policy
attack-id: T1615
definition: Adversaries may gather information on Group Policy settings to identify paths for privilege escalation, security measures applied within a domain, and to discover patterns in domain objects that can be manipulated or used to blend in the environment. Group Policy allows for centralized management of user and computer settings in Active Directory (AD). Group policy objects (GPOs) are containers for group policy settings made up of files stored within a predictable network path `\<DOMAIN>\SYSVOL\<DOMAIN>\Policies\`.(Citation: TechNet Group Policy Basics)(Citation: ADSecurity GPO Persistence 2016)

Cloud Storage Object Discovery
type: Class
subclass of: Discovery Technique
subclass of: Restriction
  on property: accesses
  some values from: Cloud Storage
type: NamedIndividual
accesses: Cloud Storage
attack-id: T1619
definition: Adversaries may enumerate objects in cloud storage infrastructure. Adversaries may use this information during automated discovery to shape follow-on behaviors, including requesting all or specific objects from cloud storage. Similar to [File and Directory Discovery](https://attack.mitre.org/techniques/T1083) on a local host, after identifying available storage services (i.e. [Cloud Infrastructure Discovery](https://attack.mitre.org/techniques/T1580)) adversaries may access the contents/objects stored in cloud infrastructure.

Reflective Code Loading
type: Class
subclass of: Defense Evasion Technique
subclass of: Restriction
  on property: modifies
  some values from: Process Segment
type: NamedIndividual
modifies: Process Segment
attack-id: T1620
definition: Adversaries may reflectively load code into a process in order to conceal the execution of malicious payloads. Reflective loading involves allocating then executing payloads directly within the memory of the process, vice creating a thread or process backed by a file path on disk (e.g., [Shared Modules](https://attack.mitre.org/techniques/T1129)).

Multi-Factor Authentication Request Generation
type: Class
subclass of: Credential Access Technique
attack-id: T1621
definition: Adversaries may attempt to bypass multi-factor authentication (MFA) mechanisms and gain access to accounts by generating MFA requests sent to users.

Debugger Evasion
type: Class
subclass of: Defense Evasion Technique
subclass of: Discovery Technique
attack-id: T1622
definition: Adversaries may employ various means to detect and avoid debuggers. Debuggers are typically used by defenders to trace and/or analyze the execution of potential malware payloads.(Citation: ProcessHacker Github)

Plist File Modification
type: Class
subclass of: Defense Evasion Technique
attack-id: T1647
definition: Adversaries may modify property list files (plist files) to enable other malicious activity, while also potentially evading and bypassing system defenses. macOS applications use plist files, such as the info.plist file, to store properties and configuration settings that inform the operating system how to handle the application at runtime. Plist files are structured metadata in key-value pairs formatted in XML based on Apple's Core Foundation DTD. Plist files can be saved in text or binary format.(Citation: fileinfo plist file description)

Serverless Execution
type: Class
subclass of: Execution Technique
attack-id: T1648
definition: Adversaries may abuse serverless computing, integration, and automation services to execute arbitrary code in cloud environments. Many cloud providers offer a variety of serverless resources, including compute engines, application integration services, and web servers.

Steal or Forge Authentication Certificates
type: Class
subclass of: Credential Access Technique
attack-id: T1649
definition: Adversaries may steal or forge certificates used for authentication to access remote systems or resources. Digital certificates are often used to sign and encrypt messages and/or files. Certificates are also used as authentication material. For example, Azure AD device certificates and Active Directory Certificate Services (AD CS) certificates bind to an identity and can be used as credentials for domain accounts.(Citation: O365 Blog Azure AD Device IDs)(Citation: Microsoft AD CS Overview)

Acquire Access
type: Class
subclass of: Resource Development Technique
attack-id: T1650
definition: Adversaries may purchase or otherwise acquire an existing access to a target system or network. A variety of online services and initial access broker networks are available to sell access to previously compromised systems.(Citation: Microsoft Ransomware as a Service)(Citation: CrowdStrike Access Brokers)(Citation: Krebs Access Brokers Fortune 500) In some cases, adversary groups may form partnerships to share compromised systems with each other.(Citation: CISA Karakurt 2022)

Cloud Administration Command
type: Class
subclass of: Execution Technique
attack-id: T1651
definition: Adversaries may abuse cloud management services to execute commands within virtual machines. Resources such as AWS Systems Manager, Azure RunCommand, and Runbooks allow users to remotely run scripts in virtual machines by leveraging installed virtual machine agents. (Citation: AWS Systems Manager Run Command)(Citation: Microsoft Run Command)

Device Driver Discovery
type: Class
subclass of: Discovery Technique
attack-id: T1652
definition: Adversaries may attempt to enumerate local device drivers on a victim host. Information about device drivers may highlight various insights that shape follow-on behaviors, such as the function/purpose of the host, present security tools (i.e. [Security Software Discovery](https://attack.mitre.org/techniques/T1518/001)) or other defenses (e.g., [Virtualization/Sandbox Evasion](https://attack.mitre.org/techniques/T1497)), as well as potential exploitable vulnerabilities (e.g., [Exploitation for Privilege Escalation](https://attack.mitre.org/techniques/T1068)).

Power Settings
type: Class
subclass of: Persistence Technique
attack-id: T1653
definition: Adversaries may impair a system's ability to hibernate, reboot, or shut down in order to extend access to infected machines. When a computer enters a dormant state, some or all software and hardware may cease to operate which can disrupt malicious activity.(Citation: Sleep, shut down, hibernate)

Log Enumeration
type: Class
subclass of: Discovery Technique
attack-id: T1654
definition: Adversaries may enumerate system and service logs to find useful data. These logs may highlight various types of valuable insights for an adversary, such as user authentication records ([Account Discovery](https://attack.mitre.org/techniques/T1087)), security or vulnerable software ([Software Discovery](https://attack.mitre.org/techniques/T1518)), or hosts within a compromised network ([Remote System Discovery](https://attack.mitre.org/techniques/T1018)).

Impersonation
type: Class
subclass of: Defense Evasion Technique
attack-id: T1656
definition: Adversaries may impersonate a trusted person or organization in order to persuade and trick a target into performing some action on their behalf. For example, adversaries may communicate with victims (via [Phishing for Information](https://attack.mitre.org/techniques/T1598), [Phishing](https://attack.mitre.org/techniques/T1566), or [Internal Spearphishing](https://attack.mitre.org/techniques/T1534)) while impersonating a known sender such as an executive, colleague, or third-party vendor. Established trust can then be leveraged to accomplish an adversary’s ultimate goals, possibly against multiple victims.

Financial Theft
type: Class
subclass of: Impact Technique
attack-id: T1657
definition: Adversaries may steal monetary resources from targets through extortion, social engineering, technical theft, or other methods aimed at their own financial gain at the expense of the availability of these resources for victims. Financial theft is the ultimate objective of several popular campaign types including extortion by ransomware,(Citation: FBI-ransomware) business email compromise (BEC) and fraud,(Citation: FBI-BEC) "pig butchering,"(Citation: wired-pig butchering) bank hacking,(Citation: DOJ-DPRK Heist) and exploiting cryptocurrency networks.(Citation: BBC-Ronin)

Content Injection
type: Class
subclass of: Command and Control Technique
subclass of: Initial Access Technique
attack-id: T1659
definition: Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic. Rather than luring victims to malicious payloads hosted on a compromised website (i.e., [Drive-by Target](https://attack.mitre.org/techniques/T1608/004) followed by [Drive-by Compromise](https://attack.mitre.org/techniques/T1189)), adversaries may initially access victims through compromised data-transfer channels where they can manipulate traffic and/or inject their own content. These compromised online network channels may also be used to deliver additional payloads (i.e., [Ingress Tool Transfer](https://attack.mitre.org/techniques/T1105)) and other data to already compromised systems.(Citation: ESET MoustachedBouncer)

Hide Infrastructure
type: Class
subclass of: Command and Control Technique
attack-id: T1665
definition: Adversaries may manipulate network traffic in order to hide and evade detection of their C2 infrastructure. This can be accomplished in various ways including by identifying and filtering traffic from defensive tools,(Citation: TA571) masking malicious domains to obfuscate the true destination from both automated scanning tools and security researchers,(Citation: Schema-abuse)(Citation: Facad1ng)(Citation: Browser-updates) and otherwise hiding malicious artifacts to delay discovery and prolong the effectiveness of adversary infrastructure that could otherwise be identified, blocked, or taken down entirely.

Modify Cloud Resource Hierarchy
type: Class
subclass of: Defense Evasion Technique
attack-id: T1666
definition: Adversaries may attempt to modify hierarchical structures in infrastructure-as-a-service (IaaS) environments in order to evade defenses.

Initial Access
type: Class
subclass of: ATTACK Enterprise Tactic
subclass of: Offensive Tactic
type: NamedIndividual
type: Offensive Tactic
display-order: 1

Execution
type: Class
subclass of: ATTACK Enterprise Tactic
subclass of: Offensive Tactic
type: NamedIndividual
type: Offensive Tactic
display-order: 2

Persistence
type: Class
subclass of: ATTACK Enterprise Tactic
subclass of: Offensive Tactic
type: NamedIndividual
type: Offensive Tactic
display-order: 3

Privilege Escalation
type: Class
subclass of: ATTACK Enterprise Tactic
subclass of: Offensive Tactic
type: NamedIndividual
type: Offensive Tactic
display-order: 4

Defense Evasion
type: Class
subclass of: ATTACK Enterprise Tactic
subclass of: Offensive Tactic
type: NamedIndividual
type: Offensive Tactic
display-order: 5

Credential Access
type: Class
subclass of: ATTACK Enterprise Tactic
subclass of: Offensive Tactic
type: NamedIndividual
type: Offensive Tactic
display-order: 6

Discovery
type: Class
subclass of: ATTACK Enterprise Tactic
subclass of: Offensive Tactic
type: NamedIndividual
type: Offensive Tactic
display-order: 7

Lateral Movement
type: Class
subclass of: ATTACK Enterprise Tactic
subclass of: Offensive Tactic
type: NamedIndividual
type: Offensive Tactic
display-order: 8

Collection
type: Class
subclass of: ATTACK Enterprise Tactic
subclass of: Offensive Tactic
type: NamedIndividual
type: Offensive Tactic
display-order: 9

Exfiltration
type: Class
subclass of: ATTACK Enterprise Tactic
subclass of: Offensive Tactic
type: NamedIndividual
type: Offensive Tactic
display-order: 11

Command And Control
type: Class
subclass of: ATTACK Enterprise Tactic
subclass of: Offensive Tactic
type: NamedIndividual
type: Offensive Tactic
display-order: 10

Impact
type: Class
subclass of: ATTACK Enterprise Tactic
subclass of: Offensive Tactic
type: NamedIndividual
type: Offensive Tactic
display-order: 12

Resource Development
type: Class
subclass of: ATTACK Enterprise Tactic
subclass of: Offensive Tactic
type: NamedIndividual
display-order: 0

Reconnaissance
type: Class
subclass of: ATTACK Enterprise Tactic
subclass of: Offensive Tactic
type: NamedIndividual
display-order: -1

TCP Event
type: Class
subclass of: Transport Layer Event
definition: An event involving the Transmission Control Protocol (TCP), providing reliable, ordered, and error-checked delivery of data between applications.

TFTP Network Traffic
type: Class
subclass of: Network Traffic
type: NamedIndividual
definition: TFTP Network Traffic is network traffic typically used to automatically transfer configuration or boot files between machines.

TFTP Server
type: Class
subclass of: Server
definition: Trivial File Transfer Protocol (TFTP) is a simple file transfer protocol, typically used to automatically transfer configuration or boot files between machines. It is used where user authentication and directory visibility are not required.

TPM Boot Integrity
type: Class
subclass of: Platform Hardening
type: NamedIndividual
kb-reference: Reference-TrustedAttestationProtocolUseCases
d3fend-id: D3-TBI
definition: Assuring the integrity of a platform by demonstrating that the boot process starts from a trusted combination of hardware and software and continues until the operating system has fully booted and applications are running. Sometimes called Static Root of Trust Measurement (STRM).
kb-article: ## How it works During the boot process, the BIOS boot block (which with this defense enabled, is the Core Root of Trust for Measurement) measures boot components (firmware, ROM). The TPM hashes those measurements and stores the hashes in Platform Configuration Registers (PCRs). Upon a subsequent boot, these hashes are provided to a verifier which compares the stored measurements to the new boot measurements. Integrity of the boot components is assured if they match. Attestation of the secure boot occurs when a verifying entity requests a Quote which is a concatenation of the requested PCR values, hashed and signed by the TPM's unique RSA key. The TPM signature is trusted because the private key is stored securely in hardware and never leaves the TPM. ## Considerations * The TPM does not perform the follow-on actions of acting on the PCR value information, it just provides the PCR stored information. * The current version of TPM is 2.0.; most existing implementations use TPM 1.2. ## Citations [1] [TPM 2.0 Library](https://trustedcomputinggroup.org/resource/tpm-library-specification/) [2] [TCG Trusted Attestation Protocol (TAP) Use Cases for TPM Families 1.2 and 2.0 and DICE](https://trustedcomputinggroup.org/wp-content/uploads/TCG_TNC_TAP_Use_Cases_v1r0p35_published.pdf)
synonym: STRM
synonym: Static Root of Trust Measurement

Tablet Computer
type: Class
subclass of: Personal Computer
definition: A tablet computer, commonly shortened to tablet, is a mobile device, typically with a mobile operating system and touchscreen display processing circuitry, and a rechargeable battery in a single, thin and flat package. Tablets, being computers, do what other personal computers do, but lack some input/output (I/O) abilities that others have. Modern tablets largely resemble modern smartphones, the only differences being that tablets are relatively larger than smartphones, with screens 7 inches (18 cm) or larger, measured diagonally, and may not support access to a cellular network.
alternative label: Tablet

Target Audience
type: Class
subclass of: Agent Group

Technique
type: Class
subclass of: Plan

Technique Reference
type: Class
subclass of: D3FEND KB Thing
subclass of: Restriction
  on property: kb-reference-of
  some values from: Defensive Technique
subclass of: Restriction
  on property: has-link
  some values from: anyURI
subclass of: Restriction
  on property: kb-reference-title
  some values from: string
definition: A reference used to develop KB articles.
pref-label: Technique Reference

Temporal Difference Learning
type: Class
subclass of: Model-free Reinforcement Learning
type: NamedIndividual
d3fend-id: D3A-TDL
definition: Temporal difference (TD) learning refers to a class of model-free reinforcement learning methods which learn by bootstrapping from the current estimate of the value function. These methods sample from the environment, like Monte Carlo methods, and perform updates based on current estimates, like dynamic programming methods
kb-article: ## References Temporal difference learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Temporal_difference_learning).
comment: Temporal difference (TD) learning refers to a class of model-free reinforcement learning methods which learn by bootstrapping from the current estimate of the value function.

Temporal Logic
type: Class
subclass of: Modal Logic
type: NamedIndividual
d3fend-id: D3A-TL
definition: Temporal logic addresses the semantics of tense; i.e., qualifying expressions of when.
kb-article: ## References 1. Temporal logic. (2023, June 4). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Modal_logic#Temporal_logic)

Terminate Process
type: Class
subclass of: System Call
subclass of: Restriction
  on property: terminates
  some values from: Process
type: NamedIndividual
terminates: Process
definition: On many computer operating systems, a computer process terminates its execution by making an exit system call. More generally, an exit in a multithreading environment means that a thread of execution has stopped running. For resource management, the operating system reclaims resources (memory, files, etc.) that were used by the process. The process is said to be a dead process after it terminates.

Tertiary Storage
type: Class
subclass of: Hardware Device
subclass of: Memory Block
subclass of: Secondary Storage
definition: Tertiary storage or tertiary memory is memory primarily used for archiving rarely accessed information. It is primarily useful for extraordinarily large data stores. Typical examples include tape libraries and optical jukeboxes.

Test Execution Tool
type: Class
subclass of: Developer Application
definition: A test execution tool is a type of software used to test software, hardware or complete systems. Synonyms of test execution tool include test execution engine, test executive, test manager, test sequencer. Two common forms in which a test execution engine may appear are as a: (a) module of a test software suite (test bench) or an integrated development environment, or (b) stand-alone application software.
alternative label: Test Execution Engine
alternative label: Test Executive
alternative label: Test Manager

Thin Client Computer
type: Class
subclass of: Shared Computer
definition: A thin client is a lightweight computer that has been optimized for establishing a remote connection with a server-based computing environment. The server does most of the work, which can include launching software programs, performing calculations, and storing data. This contrasts with a fat client or a conventional personal computer; the former is also intended for working in a client-server model but has significant local processing power, while the latter aims to perform its function mostly locally. Thin clients are shared computers as the thin client's computing resources are provided by a remote server.

Thread
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual

Thread Start Function
type: Class
subclass of: Subroutine
subclass of: Restriction
  on property: executes
  some values from: Thread
type: NamedIndividual
executes: Thread
definition: A function which invokes a create thread system call.

Ticket Granting Ticket
type: Class
subclass of: Access Token
definition: In some computer security systems, a Ticket Granting Ticket or Ticket to Get Tickets (TGT) is a small, encrypted identification file with a limited validity period. After authentication, this file is granted to a user for data traffic protection by the key distribution center (KDC) subsystem of authentication services such as Kerberos. The TGT file contains the session key, its expiration date, and the user's IP address, which protects the user from man-in-the-middle attacks. The TGT is used to obtain a service ticket from Ticket Granting Service (TGS). User is granted access to network services only after this service ticket is provided.
alternative label: Golden Ticket

Time Series Analysis
type: Class
subclass of: Statistical Method
type: NamedIndividual
d3fend-id: D3A-TSA
definition: Time series analysis comprises methods for analyzing time series data in order to extract meaningful statistics and other characteristics of the data.
kb-article: ## References Wikipedia. (n.d.). Time series. [Link](https://en.wikipedia.org/wiki/Time_series)

Token-based Authentication
type: Class
subclass of: Agent Authentication
subclass of: Restriction
  on property: uses
  some values from: Access Token
type: NamedIndividual
kb-reference: Reference-Entrust-What-Is-Token-Based-Authentication
uses: Access Token
d3fend-id: D3-TBA
definition: Token-based authentication is an authentication protocol where users verify their identity in exchange for a unique access token. Users can then access the website, application, or resource for the life of the token without having to re-enter their credentials.
kb-article: ## How it works Token-based authentication starts with a user logging into a system, device or application, typically using a password or a security question. An authorization server validates that initial authentication and then issues an access token, which is a small piece of data that lets a client application make a secure call or signal to an API server. Once this initial token-based authentication protocol is completed, the token works like a stamped ticket: The user can continue to seamlessly access the relevant resources, without re-authenticating, for the duration of the token lifecycle. That lifecycle ends when the user logs out or quits an app — and can also be triggered by a set time-out protocol. ## Considerations: While token-based authentication is undoubtedly a major step above traditional password-based authentication, the token is still considered a “bearer token” — that is, access is granted to whomever holds the token.

Token Binding
type: Class
subclass of: Credential Hardening
subclass of: Restriction
  on property: strengthens
  some values from: Access Token
type: NamedIndividual
strengthens: Access Token
d3fend-id: D3-TB
definition: Token binding is a security mechanism used to enhance the protection of tokens, such as cookies or OAuth tokens, by binding them to a specific connection.
kb-article: ## How it works When issuing a security token to a client that supports Token Binding, a server includes the client's Token Binding ID (or its cryptographic hash) in the token. Later on, when a client presents a security token containing a Token Binding ID, the server verifies that the ID in the token matches the ID of the Token Binding established with the client. In the case of a mismatch, the server rejects the token. ## Considerations - While industry participation in the standards process is widespread, browser support remains limited. - In practice, token-binding implementations are tied to Transport Security Layer (TLS).

Trace Process
type: Class
subclass of: System Call
subclass of: Restriction
  on property: monitors
  some values from: Process
type: NamedIndividual
monitors: Process
definition: A trace system call provides a means by which one process (the "tracer") may observe and control the execution of another process (the "tracee"), and examine and change the tracee's memory and registers. It is primarily used to implement breakpoint debugging and system call tracing.
alternative label: Open Process

Trace Thread
type: Class
subclass of: System Call
type: NamedIndividual

Trajectory Prediction
type: Class
subclass of: Forecasting

Transducer Sensor
type: Class
subclass of: Sensor

Transfer Agent Authentication
type: Class
subclass of: Message Hardening
type: NamedIndividual
kb-reference: Reference-DomainKeysIdentifiedMail-Signatures-IETF
kb-reference: Reference-RFC7208-SenderPolicyFramework-SPF-ForAuthorizingUseOfDomainsInEmail-IETF
kb-reference: Reference-RFC7489-Domain-basedMessageAuthentication-Reporting-AndConformance-DMARC
d3fend-id: D3-TAAN
definition: Validating that server components of a messaging infrastructure are authorized to send a particular message.
kb-article: ## How it works Transfer Agent Authentication can be accomplished in different ways for depending on the protocol. In Email, Sender Policy Framework (SPF), Domain Key Identified Email (DKIM) or Domain-based Message Authentication Reporting and Conformance (DMARC) are used to validate sender domain ownership. ### SPF SPF protocol allows for mail domain owners to specify the mail servers they use when sending email. SPF requires the use of SPF records published in the Domain Name System (DNS). The records record the authorized IPs for email senders. SPF uses the return-path address for domain IP identification. Email that is forwarded may cause the return-path validation problems. ### DKIM DKIM also uses a record entry in DNS for authentication but does not rely on the simple return-path for validation. A signature header is added to email and encryption is used for security. This adds an additional layer of complexity and requires that DKIM servers be configured identified cryptographic signatures. The additional complexity results in a validation process that can survive complex routing of emails. ### DMARC DMARC is an email policy and authentication protocol that seeks to ensure that the "From" field of emails is not spoofed. DMARC makes use of both SPF records and DKIM published key validation. DMARC also has a decision policy framework, contained in a DMARC record, for handling of rejected email. The DMARC framework also updates DMARC domains with authentication statues for allowed senders of that domain. ## Considerations - Additional work is required to ensure that all SPF, DKIM and DMARC records are current and up to date. - Maintenance of DKIM signing keys is needed. - Using SPF without DKIM and DMARC verifies the Return-Path domain however does not prevent spoofing of the displayed From: address. - Parts of an email that are not signed or verified by email authentication methods, such as the message body or the header To: and Subject: fields, can be altered …

Transfer Learning
type: Class
subclass of: Machine Learning
type: NamedIndividual
d3fend-id: D3A-TL
definition: Transfer learning (TL) is a research problem in machine learning (ML) that focuses on storing knowledge gained while solving one problem and applying it to a different but related problem.
kb-article: ## References Transfer learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Transfer_learning).

Transformer-XL
type: Class
subclass of: Transformer-based Learning
type: NamedIndividual
d3fend-id: D3A-TX
definition: Transformer-XL is a transformer architecture that introduces the notion of recurrence to the deep self-attention network. Instead of computing the hidden states from scratch for each new segment, Transformer-XL reuses the hidden states obtained in previous segments.
kb-article: ## References Transformer-XL. (n.d.). Papers with Code. [Link](https://paperswithcode.com/method/transformer-xl)

Transformer-based Learning
type: Class
subclass of: Machine Learning
type: NamedIndividual
d3fend-id: D3A-TBL
definition: A transformer is a deep learning model. It is distinguished by its adoption of self-attention, differentially weighting the significance of each part of the input (which includes the recursive output) data.
kb-article: ## References "Transformer (machine learning model)." Wikipedia. [Link](https://en.wikipedia.org/wiki/Transformer_(machine_learning_model)).

Translation Lookaside Buffer
type: Class
subclass of: Memory Management Unit Component
type: NamedIndividual
definition: A translation lookaside buffer (TLB) is a memory cache that is used to reduce the time taken to access a user memory location. It is a part of the chip's memory-management unit (MMU).

Transport Layer Event
type: Class
subclass of: Network Event
definition: An event occurring at the transport layer, responsible for end-to-end communication and data transfer management.

Transport Link
type: Class
subclass of: Logical Link

Trimmed Mean
type: Class
subclass of: Central Tendency
type: NamedIndividual
d3fend-id: D3A-TM
definition: The arithmetic mean of data values after a certain number or proportion of the highest and lowest data values have been discarded.
kb-article: ## References Wikipedia. (n.d.). Central tendency. [Link](https://en.wikipedia.org/wiki/Central_tendency)
synonym: Truncated mean

Trust Store
type: Class
subclass of: Digital Information Bearer
definition: Stores public information necessary to determine if another party can be trusted.

Trusted Library
type: Class
subclass of: Source Code Hardening
subclass of: Restriction
  on property: hardens
  some values from: Subroutine
type: NamedIndividual
hardens: Subroutine
kb-reference: Reference-LeverageSecurityFrameworksLibraries OWASP
d3fend-id: D3-TL
definition: A trusted library is a collection of pre-verified and secure code modules or components that are used within software applications to perform specific functions. These libraries are considered reliable and have been vetted for security vulnerabilities, ensuring they do not introduce risks into the application.
kb-article: ## How it Works Using a trusted library can reduce the chances of introducing errors compared to writing code from scratch. ## Considerations Note: This resource should not be considered a definitive or exhaustive coding guideline.

Tunnel Close Event
type: Class
subclass of: Tunnel Event
definition: An event where a network tunnel is terminated, ending encapsulated communication and releasing the associated resources.

Tunnel Event
type: Class
subclass of: Network Event
definition: An event involving the establishment, usage, or termination of a network tunnel. Tunnels provide encapsulated communication pathways across various layers, enabling secure, isolated, or virtualized transport of data.

Tunnel Open Event
type: Class
subclass of: Tunnel Event
definition: An event where a network tunnel is established, enabling encapsulated communication between endpoints. This marks the initiation of secure or isolated data transport through the tunnel.

Tunnel Renew Event
type: Class
subclass of: Tunnel Event
definition: An event where the lifecycle of a network tunnel is extended, ensuring continued encapsulated communication and avoiding session expiration.

UDP Event
type: Class
subclass of: Transport Layer Event
definition: An event involving the User Datagram Protocol (UDP), providing a connectionless datagram service with minimal protocol mechanisms.

URL
type: Class
subclass of: Identifier
subclass of: Restriction
  on property: addresses
  some values from: Resource
type: NamedIndividual
addresses: Resource
definition: A Uniform Resource Locator (URL), commonly informally termed a web address (a term which is not defined identically) is a reference to a web resource that specifies its location on a computer network and a mechanism for retrieving it.A URL is a specific type of Uniform Resource Identifier (URI), although many people use the two terms interchangeably. A URL implies the means to access an indicated resource, which is not true of every URI. URLs occur most commonly to reference web pages (http), but are also used for file transfer (ftp), email (mailto), database access (JDBC), and many other applications.
alternative label: Uniform Resource Locator

URL Analysis
type: Class
subclass of: Identifier Analysis
subclass of: Restriction
  on property: analyzes
  some values from: URL
type: NamedIndividual
analyzes: URL
kb-reference: Reference-MethodAndApparatusForDetectingMaliciousWebsites EndgameInc
kb-reference: Reference-MethodAndSystemForDetectingRestrictedContentAssociatedWithRetrievedContent SophosLtd
d3fend-id: D3-UA
definition: Determining if a URL is benign or malicious by analyzing the URL or its components.
kb-article: ## How it works URLs may contain components, for example: * scheme * userinfo * host name * port * path * query * fragment These components are used as features in analysis algorithms. Contextual information about a URL such as where it is embedded (ex. emails, files, network protocols), header, path, location, and origin information, as well as information about the content returned from the URL request, may be incorporated into an analytic for URL analysis. For example, if a URL indicates a .pdf file but an executable is actually returned, the combination of these two pieces of information indicates suspicious activity. Additional techniques include: * Extracting features of a URL such as domain name length, ratio of consecutive consonants, percentage of digits in a domain, and number of vowels. Values for each feature are combined to develop a score for the URL. * Determining the probability of a character occurring in the URL given the preceding two characters. For example, for google.com, the probability of a 'g' occurring at the beginning of a word, the probability of an 'o' occurring after a "g, the probability of an o" occurring after a 'g' and "o, and so forth. A dictionary or a list of known good domains is used to determine probability. Probabilities are multiplied to develop a score for the URL. URL analysis may trigger follow-on analytics such as **File Analysis** ## Considerations * Volume of URLs being analyzed, combined with the speed at which they are analyzed * Fidelity of analysis technique at detecting brand new URLs versus analyzing URLs of established domains

URL Reputation Analysis
type: Class
subclass of: Identifier Reputation Analysis
subclass of: Restriction
  on property: analyzes
  some values from: URL
type: NamedIndividual
analyzes: URL
kb-reference: Reference-Finding phishing sites
d3fend-id: D3-URA
definition: Analyzing the reputation of a URL.

Uncertainty Sampling
type: Class
subclass of: Active Learning
type: NamedIndividual
d3fend-id: D3A-US
definition: Makes the utility inversely proportional to the uncertainty of the model with respect to the sample and will work with any model provided it can assess its uncertainty of a predection.
kb-article: ## References Intro to Active Learning. inovex Blog. [Link](https://www.inovex.de/de/blog/intro-to-active-learning/).

Unit Test Execution Tool
type: Class
subclass of: Test Execution Tool
definition: An unit test execution tool automatically performs unit testing. Unit testing is a software testing method by which individual units of source code are tested to determine whether they are fit for use. Unit test execution tools work with sets of one or more computer program modules together with associated control data, usage procedures, and operating procedures. This contrasts with integration testing, which tests inter-unit dependencies and the modules as a group.

Unix Hard Link
type: Class
subclass of: Hard Link
subclass of: Unix Link
definition: A Unix hard link is a hard link on a Unix file system.

Unix Link
type: Class
subclass of: File System Link
definition: A Unix link is a file link in a Unix file system.

Unload Library Event
type: Class
subclass of: Process Event
subclass of: Restriction
  on property: has-participant
  some values from: Shared Library File
definition: An event where a process unloads a dynamically linked library or module, reducing its memory footprint or functionality.

Unload Module
type: Class
subclass of: System Call
subclass of: Restriction
  on property: unloads
  some values from: Hardware Driver
subclass of: Restriction
  on property: unloads
  some values from: Kernel Module
type: NamedIndividual
unloads: Hardware Driver
unloads: Kernel Module
definition: A system call that unloads a driver or extension from the kernel.

Unlock Account
type: Class
subclass of: Restore User Account Access
subclass of: Restriction
  on property: restores
  some values from: User Account
type: NamedIndividual
kb-reference: Reference-CybersecurityIncidentandVulnerabilityResponsePlaybooks
restores: User Account
d3fend-id: D3-ULA
definition: Restoring a user account's access to resources by unlocking a locked User Account.

Unsupervised Learning
type: Class
subclass of: Machine Learning
type: NamedIndividual
d3fend-id: D3A-UL
definition: Unsupervised learning creates relationships with unlabeled data without the input of a human or other outside actor. Uses only input data.
kb-abstract: ## References Unsupervised learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Unsupervised_learning).

Unsupervised Preprocessing
type: Class
subclass of: Semi-Supervised Learning
type: NamedIndividual
d3fend-id: D3A-UP
definition: When performing unsupervised learning, the machine is presented with unlabeled data. (Unlabeled data has no target.) Unsupervised learning algorithms seek to discover intrinsic patterns that underlie the data, such as a clustering parameter or a redundant parameter (dimension) that can be reduced.
kb-article: ## References SAS Institute Inc. (n.d.). Decision Trees. In SAS® Visual Data Mining and Machine Learning.[Link](https://documentation.sas.com/doc/en/vdmmlcdc/8.4/vdmmladvug/n1e4spzcnv1f0fn1vsxhbzgdp1bb.htm).

Use Case Goal
type: Class
subclass of: Goal

Use Case Prerequisite
type: Class
subclass of: Condition

Use Case Procedure
type: Class
subclass of: Procedure

Use Case Step
type: Class
subclass of: Step

User
type: Class
subclass of: Agent
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: has-account
  some values from: User Account
subclass of: Restriction
  on property: restricted-by
  some values from: Access Control List
type: NamedIndividual
has-account: User Account
restricted-by: Access Control List
definition: A user is a person [or agent] who uses a computer or network service. Users generally use a system or a software product without the technical expertise required to fully understand it. Power users use advanced features of programs, though they are not necessarily capable of computer programming and system administration. A user often has a user account and is identified to the system by a username (or user name). Other terms for username include login name, screenname (or screen name), nickname (or nick) and handle, which is derived from the identical Citizen's Band radio term. Some software products provide services to other systems and have no direct end users.

User Account
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: identified-by
  some values from: Digital Identity
subclass of: Restriction
  on property: used-by
  some values from: Agent
type: NamedIndividual
identified-by: Digital Identity
used-by: Agent
definition: A user account allows a user to authenticate to a system and potentially to receive authorization to access resources provided by or connected to that system; however, authentication does not imply authorization. To log into an account, a user is typically required to authenticate oneself with a password or other credentials for the purposes of accounting, security, logging, and resource management.

User Account Attach Policy Event
type: Class
subclass of: User Account Event
definition: An event where an IAM policy is attached to a user account.

User Account Creation Event
type: Class
subclass of: User Account Event
definition: An event representing the creation of a new user account within a system or domain.

User Account Deletion Event
type: Class
subclass of: User Account Event
definition: An event representing the permanent deletion of a user account from a system or domain.

User Account Detach Policy Event
type: Class
subclass of: User Account Event
definition: An event where an IAM policy is detached from a user account.

User Account Disable Event
type: Class
subclass of: User Account Event
definition: An event where a user account is disabled, preventing its active use within the system.

User Account Enable Event
type: Class
subclass of: User Account Event
definition: An event where a user account is enabled, granting it active use within the system.

User Account Event
type: Class
subclass of: Digital Event
subclass of: Restriction
  on property: has-participant
  some values from: User Account
definition: An event capturing operations or state changes performed on user accounts, including lifecycle management, access control modifications, and policy assignments.

User Account Lock Event
type: Class
subclass of: User Account Event
definition: An event where a user account is locked out due to failed authentication attempts or administrative action.

User Account MFA Disable Event
type: Class
subclass of: User Account Event
definition: An event where multi-factor authentication (MFA) is disabled for a user account.

User Account MFA Enable Event
type: Class
subclass of: User Account Event
definition: An event where multi-factor authentication (MFA) is enabled for a user account.

User Account Password Change Event
type: Class
subclass of: User Account Event
definition: An event where a user account's password is modified, typically by the user or an administrator.

User Account Password Reset Event
type: Class
subclass of: User Account Event
definition: An event where a user account's password is reset, typically due to a forgotten password or administrative action.

User Account Permissions
type: Class
subclass of: Access Policy Administration
subclass of: Restriction
  on property: restricts
  some values from: User Account
type: NamedIndividual
kb-reference: Reference-ConfigureUserAccessControlAndPermissions
restricts: User Account
d3fend-id: D3-UAP
definition: Restricting a user account's access to resources.

User Account Update Event
type: Class
subclass of: User Account Event
definition: An event capturing updates to a user account, including changes to its attributes or configuration.

User Action
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: records
  some values from: Action
type: NamedIndividual
records: Action
definition: An action performed by a user. Executing commands, granting permissions, and accessing resources are examples of user actions.

User Application
type: Class
subclass of: Application
definition: A user application is executed for that an individual user on a user's personal computer or remotely by means of virtualization. This is in contrast to service applications or enterprise software.

User Behavior
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: contains
  some values from: User Action
type: NamedIndividual
contains: User Action
definition: A user behavior is a pattern of user actions, or set of such patterns. Modeling and analyzing these patterns and monitoring a users actions for meaningful anomalies is known as user behavior analytics (UBA).

User Behavior Analysis
type: Class
subclass of: Defensive Technique
subclass of: Restriction
  on property: enables
  some values from: Detect
type: NamedIndividual
enables: Detect
d3fend-id: D3-UBA
definition: User behavior analytics ("UBA") as defined by Gartner, is a cybersecurity process about detection of insider threats, targeted attacks, and financial fraud. UBA solutions look at patterns of human behavior, and then apply algorithms and statistical analysis to detect meaningful anomalies from those patterns-anomalies that indicate potential threats.' Instead of tracking devices or security events, UBA tracks a system's users. Big data platforms are increasing UBA functionality by allowing them to analyze petabytes worth of data to detect insider threats and advanced persistent threats.
kb-article: ## Technique Overview Some techniques monitor patterns of human behavior and then apply algorithms and to identify patterns such as repeated login attempts from a single IP address or large file downloads, or abnormal accesses. Other techniques may have explicit or rigid definitions of "bad behavior" which are then matched against instances in a computer network environment.
synonym: Credential Monitoring
synonym: UBA

User Data Transfer Analysis
type: Class
subclass of: User Behavior Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Resource Access
type: NamedIndividual
analyzes: Resource Access
kb-reference: Reference-SystemAndMethodThereofForIdentifyingAndRespondingToSecurityIncidentsBasedOnPreemptiveForensics PaloAltoNetworksInc
kb-reference: Reference-SystemForImplementingThreatDetectionUsingThreatAndRiskAssessmentOfAsset-actorInteractions VECTRANETWORKSInc
d3fend-id: D3-UDTA
definition: Analyzing the amount of data transferred by a user.
kb-article: ## How it works Unusual data transfer activity may indicate unauthorized activity. Data transfers can be analyzed by collecting network traffic or application logs. ## Considerations * There is a potential for false positives from anomalies that are not associated with unauthorized activity. * Attackers that move low and slow may not differentiate their data transfer behavior enough for an alert to trigger.

User Geolocation Logon Pattern Analysis
type: Class
subclass of: User Behavior Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Network Traffic
type: NamedIndividual
analyzes: Network Traffic
kb-reference: Reference-MethodAndApparatusForNetworkFraudDetectionAndRemediationThroughAnalytics IdaptiveLLC
kb-reference: Reference-System,Method,AndComputerProgramProductForDetectingAndAssessingSecurityRisksInANetwork ExabeamInc
d3fend-id: D3-UGLPA
definition: Monitoring geolocation data of user logon attempts and comparing it to a baseline user behavior profile to identify anomalies in logon location.
kb-article: ## How it works Geolocation data for each user logon attempt is collected and used to create a baseline user behavior profile. Current geolocation logon data is then compared against the user behavior profile. Logon activity that deviates from normal patterns and can help in identifying situations that may be indicative of a remote attacker using stolen credentials. For example: * logons from locations that are different from where a user usually logs in * logons from a location in which an enterprise has no users located * logon that is not physically possible given the elapsed time since a logon from another location. ## Considerations * Potential for false positives from logon anomalies that are not associated with malicious activity. * Attackers may not differentiate their logon behavior enough to trigger an alert.

User Group
type: Class
subclass of: Access Control Group
subclass of: Restriction
  on property: contains
  some values from: User
type: NamedIndividual
contains: User
definition: User groups are a way to collect user accounts and/or computer accounts into manageable units. Administrators can assign permissions, roles, or access to resources, as well as modify group membership, depending on the operating system.
synonym: Security Group

User Init Configuration File
type: Class
subclass of: Configuration File
subclass of: User Logon Init Resource
type: NamedIndividual
definition: A user initialization configuration file is a file containing the information necessary to configure that part of a user's environment which is common to all applications and actions. User configurations may be overridden by more specific configuration information (such as that found in a application configuration file.)
alternative label: User Configuration File

User Init Script
type: Class
subclass of: Executable Script
subclass of: Init Script
subclass of: User Logon Init Resource
type: NamedIndividual
definition: A script used to initialize and configure elements of the user's applications and user environment.

User Input Function
type: Class
subclass of: Input Function
type: NamedIndividual
definition: Generic function that receives direct user input from an untrusted source.

User Interface
type: Class
subclass of: Digital Information Bearer
definition: The user interface (UI), in the industrial design field of human-machine interaction, is the space where interactions between humans and machines occur. The goal of this interaction is to allow effective operation and control of the machine from the human end, whilst the machine simultaneously feeds back information that aids the operators' decision-making process. Examples of this broad concept of user interfaces include the interactive aspects of computer operating systems, hand tools, heavy machinery operator controls, and process controls. The design considerations applicable when creating user interfaces are related to or involve such disciplines as ergonomics and psychology.
alternative label: UI

User Logon Init Resource
type: Class
subclass of: Local Resource
type: NamedIndividual
definition: A user logon initialization resource contains information used to configure a user's environment when a user logs into a system.

User Manual Reference
type: Class
subclass of: Technique Reference
pref-label: User Manual

User Process
type: Class
subclass of: Process
type: NamedIndividual
definition: A user process is a process running to perform functions in the name of on particular user and user account, such as run an application or application service serving any number users. This is in contrast to a system process, which executes software to fulfill operating system functions.

User Profile
type: Class
subclass of: Digital Information Bearer
definition: A user profile is a collection of settings and information associated with a user. It contains critical information that is used to identify an individual, such as their name, age, portrait photograph and individual characteristics such as knowledge or expertise.

User Session Init Config Analysis
type: Class
subclass of: Operating System Monitoring
subclass of: Restriction
  on property: analyzes
  some values from: User Init Configuration File
type: NamedIndividual
analyzes: User Init Configuration File
kb-reference: Reference-IdentificationAndExtractionOfKeyForensicsIndicatorsOfCompromiseUsingSubject-specificFilesystemViews
kb-reference: Reference-RegistryKeySecurityAndAccessRights
kb-reference: Reference-CAR-2020-09-002:ComponentObjectModelHijacking MITRE
kb-reference: Reference-CAR-2020-11-011:RegistryEditFromScreensaver
d3fend-id: D3-USICA
definition: Analyzing modifications to user session config files such as .bashrc or .bash_profile.
synonym: User Startup Config Analysis

User Startup Directory
type: Class
subclass of: User Logon Init Resource
subclass of: Restriction
  on property: contains
  some values from: User Startup Script File
type: NamedIndividual
contains: User Startup Script File
definition: A user startup directory holds information necessary to start the users session with the system.

User Startup Script File
type: Class
subclass of: Executable Script
subclass of: User Logon Init Resource
type: NamedIndividual
definition: A user startup script file is a shortcut file that is executed when a user logs in and starts a session on the host. These indicate applications the user wants started at login. For Windows, these are typically found in the user's startup directory.

User to User Message
type: Class
subclass of: Digital Information Bearer
subclass of: Restriction
  on property: has-recipient
  some values from: User Account
subclass of: Restriction
  on property: has-sender
  some values from: User Account
subclass of: Restriction
  on property: may-contain
  some values from: Email
type: NamedIndividual
has-recipient: User Account
has-sender: User Account
may-contain: Email
definition: Personal message, private message (PM), direct message (DM), or personal chat (PC) is a private form of messaging between different members on a given platform. It is only seen and accessible by the users participating in the message.
alternative label: Personal Message
alternative label: Private Message

Utility Software
type: Class
subclass of: Software
definition: Utility applications are software applications designed to help to analyze, configure, optimize or maintain a computer. It is used to support the computer infrastructure - in contrast to application software, which is aimed at directly performing tasks that benefit ordinary users. However, utilities often form part of the application systems. For example, a batch job may run user-written code to update a database and may then include a step that runs a utility to back up the database, or a job may run a utility to compress a disk before copying files.
alternative label: Utility Application

Virtual Machine Image
type: Class
subclass of: Storage Image
subclass of: Restriction
  on property: contains
  some values from: System State Image
type: NamedIndividual
contains: System State Image
definition: A Virtual Machine Image (VMI) is a file that encapsulates the entire state of a virtual machine at a given point in time. This includes the operating system, applications, data, and configurations. VMIs are used to create and replicate virtual machines, ensuring consistency and reliability across different environments.
alternative label: VM Image

VPN Server
type: Class
subclass of: Server
definition: A VPN server is a type of server that enables hosting and delivery of VPN services. It is a combination of VPN hardware and software technologies that provides VPN clients with connectivity to a secure and/or private network, or rather, the VPN.

Variability
type: Class
subclass of: Descriptive Statistics
type: NamedIndividual
d3fend-id: D3A-VAR
definition: Dispersion (also called variability, scatter, or spread) is the extent to which a distribution is stretched or squeezed. A measure of statistical dispersion is a nonnegative real number that is zero if all the data are the same and increases as the data become more diverse.
kb-article: ## References Wikipedia. (n.d.). Statistical dispersion. [Link](https://en.wikipedia.org/wiki/Statistical_dispersion)

Variable Initialization
type: Class
subclass of: Source Code Hardening
subclass of: Restriction
  on property: hardens
  some values from: Subroutine
type: NamedIndividual
hardens: Subroutine
kb-reference: Reference-CManualIntegerInitialization GNU
kb-reference: Reference-VariableInitialization CWE
d3fend-id: D3-VI
definition: Setting variables to a known value before use.
kb-article: ## How it Works Initializing variables upon declaration ensures that the variable has a known quantity before use. ## Considerations * Default behavior when declaring variables varies by language. * This is particularly important in programming languages that do not initialize variables to a default value upon declaration. In these instances, the value that a variable will contain after declaration is indeterminate which can cause issues. In fact, that value could be different each time the program is ran. * Note: This resource should not be considered a definitive or exhaustive coding guideline.

Variable Type Validation
type: Class
subclass of: Source Code Hardening
subclass of: Restriction
  on property: hardens
  some values from: Pointer Dereferencing Function
type: NamedIndividual
hardens: Pointer Dereferencing Function
kb-reference: Reference-TypeSystems Princeton
d3fend-id: D3-VTV
definition: Ensuring that a variable has the correct type.
kb-article: ## How it Works A developer should consider how the variable will be used throughout the program and choose the correct variable type. A developer should programmatically check if a variable has the correct (expected) type before using that variable. ## Considerations * The result of an operation on an unexpected variable type will vary based on the language. * Note: This resource should not be considered a definitive or exhaustive coding guideline.

Variance
type: Class
subclass of: Variability
type: NamedIndividual
d3fend-id: D3A-VAR
definition: Variance is a measure of dispersion, meaning it is a measure of how far a set of numbers is spread out from their average value.
kb-article: ## References Wikipedia. (n.d.). Variance. [Link](https://en.wikipedia.org/wiki/Variance)

Variance Reduction
type: Class
subclass of: Active Learning
type: NamedIndividual
d3fend-id: D3A-VR
definition: Leverages a well-known result from statistical learning and decomposes the model error into a data noise term, a model bias term and a model variance term. As the noise term only depends on the data and the bias is induced by the choice of model, any reduction in the error can only come from the variance term.
kb-article: ## References Intro to Active Learning. inovex Blog. [Link](https://www.inovex.de/de/blog/intro-to-active-learning/).

Vendor
type: Class
subclass of: Provider

Version Control Tool
type: Class
subclass of: Developer Application
definition: Version control tools are tools that used to conduct version control. A component of software configuration management, version control, also known as revision control, source control, or source code management systems are systems responsible for the management of changes to documents, computer programs, large web sites, and other collections of information. Changes are usually identified by a number or letter code, termed the "revision number", "revision level", or simply "revision". For example, an initial set of files is "revision 1". When the first change is made, the resulting set is "revision 2", and so on. Each revision is associated with a timestamp and the person making the change. Revisions can be compared, restored, and with some types of files, merged.
alternative label: Revision Control
alternative label: Source Control

Video Input Device
type: Class
subclass of: Input Device
type: NamedIndividual
definition: Video input devices are used to digitize images or video from the outside world into the computer. The information can be stored in a multitude of formats depending on the user's requirement.

Virtual Address
type: Class
subclass of: Memory Address
type: NamedIndividual
definition: A virtual address in memory is a pointer or marker for a memory space that an operating system allows a process to use. The virtual address points to a location in primary storage that a process can use independently of other processes.
synonym: Logical Address

Virtual Memory Space
type: Class
subclass of: Memory Address Space
definition: Virtual memory is a memory management technique where secondary memory can be used as if it were a part of the main memory. Virtual memory uses hardware and software to enable a computer to compensate for physical memory shortages

Virtualization Software
type: Class
subclass of: Service Application
type: NamedIndividual
definition: Virtualization software allows a single host computer to create and run one or more virtual environments. Virtualization software is most often used to emulate a complete computer system in order to allow a guest operating system to be run, for example allowing Linux to run as a guest on top of a PC that is natively running a Microsoft Windows operating system (or the inverse, running Windows as a guest on Linux).

Volume
type: Class
subclass of: Digital Information Bearer
type: NamedIndividual
definition: In the context of computer operating systems, a volume or logical drive is a single accessible storage area with a single file system, typically (though not necessarily) resident on a single partition of a hard disk. Although a volume might be different from a physical disk drive, it can still be accessed with an operating system's logical interface. However, a volume differs from a partition.
alternative label: Drive Volume
alternative label: Logical Drive

Volume Boot Record
type: Class
subclass of: Boot Record
type: NamedIndividual
definition: A volume boot record (VBR) (also known as a volume boot sector, a partition boot record or a partition boot sector) is a type of boot sector introduced by the IBM Personal Computer. It may be found on a partitioned data storage device, such as a hard disk, or an unpartitioned device, such as a floppy disk, and contains machine code for bootstrapping programs (usually, but not necessarily, operating systems) stored in other parts of the device. On non-partitioned storage devices, it is the first sector of the device. On partitioned devices, it is the first sector of an individual partition on the device, with the first sector of the entire device being a Master Boot Record (MBR) containing the partition table.

Volume Snapshot
type: Class
subclass of: Storage Snapshot
type: NamedIndividual
definition: A volume snapshot is a point-in-time copy of a storage volume.

Voting
type: Class
subclass of: Ensemble Learning
type: NamedIndividual
d3fend-id: D3A-VOT
definition: Voting is another form of ensembling.
kb-article: ## References Ensemble learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Ensemble_learning).

Vulnerability
type: Class
subclass of: D3FEND Core
type: NamedIndividual

Weakness
type: Class
subclass of: D3FEND Core
definition: A weakness is a condition in a software, firmware, hardware, or service component that, under certain circumstances, could contribute to the introduction of vulnerabilities.

Web API Resource
type: Class
subclass of: Web Resource
definition: A web API resource is an API resource identified by a Uniform Resource Identifier (URI) and made available from one host to another host via a web protocol and across a network or networks.

Web Access Token
type: Class
subclass of: Session Token
definition: A web access token is a credential that allows a web client application to access a specific resource to perform specific actions on behalf of the user.
synonym: WAT

Web Application Firewall
type: Class
subclass of: Application Layer Firewall
definition: A web application firewall (or WAF) filters, monitors, and blocks HTTP traffic to and from a web application. A WAF is differentiated from a regular firewall in that a WAF is able to filter the content of specific web applications while regular firewalls serve as a safety gate between servers. By inspecting HTTP traffic, it can prevent attacks stemming from web application security flaws, such as SQL injection, cross-site scripting (XSS), file inclusion, and security misconfigurations.
alternative label: WAF

Web Application Server
type: Class
subclass of: Web Server
definition: A web application server is a web server that hosts applications. Application server frameworks are software frameworks for building application servers. An application server framework provides both facilities to create web applications and a server environment to run them. In the case of Java application servers, the server behaves like an extended virtual machine for running applications, transparently handling connections to the database on one side, and, often, connections to the Web client on the other.

Web Authentication
type: Class
subclass of: Authentication
subclass of: Restriction
  on property: may-create
  some values from: Session Cookie
definition: A request-response comprising a user credential presentation to a system and a verification response where the verifying party is a web server.

Web File Resource
type: Class
subclass of: Network File Resource
subclass of: Web Resource
subclass of: Restriction
  on property: addressed-by
  some values from: URL
type: NamedIndividual
addressed-by: URL
definition: A web file resource is a file resource identified by a Uniform Resource Identifier (URI) and made available from one host to another host via a web protocol and across a network or networks.

Web Identity Token
type: Class
subclass of: Credential
subclass of: Restriction
  on property: signed-by
  some values from: Cryptographic Key
type: NamedIndividual
signed-by: Cryptographic Key
definition: An ID token is an artifact that proves that the user has been authenticated.
kb-article: ## How it works An ID token is proof of the user's authentication. An ID token is encoded as a JSON Web Token (JWT), a standard format that allows your application to easily inspect its content, and make sure it comes from the expected issuer and that no one else changed it.
synonym: Identity Token

Web Network Traffic
type: Class
subclass of: Network Traffic
type: NamedIndividual
definition: Web network traffic is network traffic that uses a standard web protocol.

Web Resource
type: Class
subclass of: Network Resource
definition: A web resource is a resource identified by a Uniform Resource Identifier (URI) and made available from one host to another host via a web protocol and across a network or networks.

Web Resource Access
type: Class
subclass of: Network Resource Access
type: NamedIndividual
definition: Ephemeral digital artifact comprising a request of a network resource and any response from that network resource using a standard web protocol.

Web Script File
type: Class
subclass of: Executable Script
type: NamedIndividual
definition: A file containing a script in a web-scripting programming language. Web scripts may be present and run on the client or on the server side.
alternative label: Web Script

Web Server
type: Class
subclass of: Server
type: NamedIndividual
definition: A web server is server software, or hardware dedicated to running this software, that can satisfy client requests on the World Wide Web. A web server can, in general, contain one or more websites. A web server processes incoming network requests over HTTP and several other related protocols. While the major function is to serve content, a full implementation of HTTP also includes ways of receiving content from clients. This feature is used for submitting web forms, including uploading of files.

Web Server Application
type: Class
subclass of: Service Application
type: NamedIndividual
definition: A web server application (or web app) is an application software that runs on a web server, unlike computer-based software programs that are stored locally on the Operating System (OS) of the device. Web applications are accessed by the user through a web browser with an active internet connection. These applications are programmed using a client-server modeled structure-the user ("client") is provided services through an off-site server that is hosted by a third-party. Examples of commonly-used, web applications, include: web-mail, online retail sales, online banking, and online auctions.
alternative label: Web App
alternative label: Web Application

Web Session Access Mediation
type: Class
subclass of: Network Resource Access Mediation
subclass of: Restriction
  on property: isolates
  some values from: Service Application Process
type: NamedIndividual
isolates: Service Application Process
kb-reference: Reference-NIST-Special-Publication-800-41-Revision-1
d3fend-id: D3-WSAM
definition: Web session access mediation secures user sessions in web applications by employing robust authentication and integrity validation, along with adaptive threat mitigation techniques, to ensure that access to web resources is authorized and protected from session-related attacks.
kb-article: ## How it works Web Session Access Mediation involves managing user access to web applications and services, ensuring secure and authorized sessions. This includes authenticating users, maintaining session integrity, and protecting against threats like session hijacking. Examples include accessing corporate intranets, SaaS applications, or online portals.

Web Session Activity Analysis
type: Class
subclass of: User Behavior Analysis
subclass of: Restriction
  on property: analyzes
  some values from: Web Resource Access
type: NamedIndividual
analyzes: Web Resource Access
kb-reference: Reference-HostIntrusionPreventionSystemUsingSoftwareAndUserBehaviorAnalysis SophosLtd
kb-reference: Reference-SystemAndMethodForDetectionOfAChangeInBehaviorInTheUseOfAWebsiteThroughVectorVelocityAnalysis SilverTailSystems
kb-reference: Reference-SystemAndMethodForNetworkSecurityIncludingDetectionOfAttacksThroughPartnerWebsites EMCIPHoldingCoLLC
kb-reference: Reference-SystemAndMethodThereofForIdentifyingAndRespondingToSecurityIncidentsBasedOnPreemptiveForensics PaloAltoNetworksInc
d3fend-id: D3-WSAA
definition: Monitoring changes in user web session behavior by comparing current web session activity to a baseline behavior profile or a catalog of predetermined malicious behavior.
kb-article: ## How it works User web session data is collected over a period of time to create a user behavior profile. Data collected includes clicks made on a website, average time between clicks, filling out web forms, order in which pages are viewed, and downloading files. Current user web session behavior is then compared against the use behavior profile to identify anomalies and a likelihood that the current user web session is malicious. Current user web session behavior can also be compared to predetermined known malicious behavior profiles that are developed through analysis of malware in run time at a threat research facility. ## Considerations * Potential for false positives from anomalies that are not associated with malicious activity. * Attackers may not differentiate their web session activity enough to trigger an alert.

Weighted Mean
type: Class
subclass of: Central Tendency
type: NamedIndividual
d3fend-id: D3A-WM
definition: A mean that incorporates weighting to certain data elements.
kb-article: ## Considerations The arithmetic mean, geometric mean, and harmonic mean can all be weighted. ## References Wikipedia. (n.d.). Central tendency. [Link](https://en.wikipedia.org/wiki/Central_tendency)

Wide Area Network
type: Class
subclass of: Network
definition: By contrast to a local area network (LAN), a wide area network (WAN), not only covers a larger geographic distance, but also generally involves leased telecommunication circuits or Internet links.
alternative label: WAN

Windows OpenFile
type: Class
subclass of: OS API Create File
subclass of: OS API Open File
subclass of: Restriction
  on property: invokes
  some values from: Windows NtOpenFile
type: NamedIndividual
invokes: Windows NtOpenFile
definition: Creates, opens, reopens, or deletes a file.

Windows CreateFileA
type: Class
subclass of: OS API Create File
subclass of: OS API Open File
subclass of: Restriction
  on property: invokes
  some values from: Windows NtCreateFile
subclass of: Restriction
  on property: invokes
  some values from: Windows NtCreateMailslotFile
subclass of: Restriction
  on property: invokes
  some values from: Windows NtCreateNamedPipeFile
subclass of: Restriction
  on property: invokes
  some values from: Windows NtCreatePagingFile
type: NamedIndividual
invokes: Windows NtCreateFile
invokes: Windows NtCreateMailslotFile
invokes: Windows NtCreateNamedPipeFile
invokes: Windows NtCreatePagingFile
definition: Creates or opens a file or I/O device. The most commonly used I/O devices are as follows: file, file stream, directory, physical disk, volume, console buffer, tape drive, communications resource, mailslot, and pipe. The function returns a handle that can be used to access the file or device for various types of I/O depending on the file or device and the flags and attributes specified.

Windows CreateProcessA
type: Class
subclass of: OS API Create Process
subclass of: Restriction
  on property: invokes
  some values from: Windows NtCreateProcess
subclass of: Restriction
  on property: invokes
  some values from: Windows NtCreateProcessEx
type: NamedIndividual
invokes: Windows NtCreateProcess
invokes: Windows NtCreateProcessEx
definition: Creates a new process and its primary thread. The new process runs in the security context of the calling process.

Windows CreateRemoteThread
type: Class
subclass of: OS API Create Thread
subclass of: Restriction
  on property: invokes
  some values from: Windows NtCreateThreadEx
type: NamedIndividual
invokes: Windows NtCreateThreadEx

Windows CreateThread
type: Class
subclass of: OS API Create Thread
subclass of: Restriction
  on property: invokes
  some values from: Windows NtCreateThread
subclass of: Restriction
  on property: invokes
  some values from: Windows NtCreateThreadEx
type: NamedIndividual
invokes: Windows NtCreateThread
invokes: Windows NtCreateThreadEx
definition: Creates a thread to execute within the virtual address space of the calling process.

Windows DeleteFile
type: Class
subclass of: OS API Delete File
subclass of: Restriction
  on property: invokes
  some values from: Windows NtDeleteFile
type: NamedIndividual
invokes: Windows NtDeleteFile
definition: Deletes an existing file.

Windows DuplicateToken
type: Class
subclass of: OS API Copy Token
subclass of: Restriction
  on property: invokes
  some values from: Windows NtDuplicateToken
type: NamedIndividual
invokes: Windows NtDuplicateToken
definition: The DuplicateToken function creates a new access token that duplicates one already in existence.

Windows GetThreadContext
type: Class
subclass of: OS API Get Thread Context
subclass of: Restriction
  on property: invokes
  some values from: Windows NtGetThreadContext
type: NamedIndividual
invokes: Windows NtGetThreadContext
definition: Retrieves the context of the specified thread.

Windows NtGetThreadContext
type: Class
subclass of: OS API Get Thread Context
type: NamedIndividual

Windows NtAllocateVirtualMemory
type: Class
subclass of: OS API Allocate Memory
type: NamedIndividual

Windows NtAllocateVirtualMemoryEx
type: Class
subclass of: OS API Allocate Memory

Windows NtCreateFile
type: Class
subclass of: OS API Create File
type: NamedIndividual

Windows NtCreateMailslotFile
type: Class
subclass of: OS API Create File
type: NamedIndividual
definition: Creates a special File Object called Mailslot.

Windows NtCreateNamedPipeFile
type: Class
subclass of: OS API Create File
type: NamedIndividual
definition: Creates Named Pipe File Object.

Windows NtCreatePagingFile
type: Class
subclass of: OS API Create File
type: NamedIndividual
definition: Typically used by Control Panel's "System" applet for creating new paged files.

Windows NtCreateProcess
type: Class
subclass of: OS API Create Process
type: NamedIndividual

Windows NtCreateProcessEx
type: Class
subclass of: OS API Create Process
type: NamedIndividual

Windows NtCreateThread
type: Class
subclass of: OS API Create Thread
type: NamedIndividual

Windows NtCreateThreadEx
type: Class
subclass of: OS API Create Thread
type: NamedIndividual

Windows NtDeleteFile
type: Class
subclass of: OS API Delete File
type: NamedIndividual
definition: Deletes the specified file.

Windows NtDuplicateToken
type: Class
subclass of: OS API Copy Token
type: NamedIndividual

Windows NtFlushInstructionCache
type: Class
subclass of: OS API Write Memory
type: NamedIndividual

Windows NtFreeVirtualMemory
type: Class
subclass of: OS API Free Memory
type: NamedIndividual

Windows NtOpenFile
type: Class
subclass of: OS API Open File
type: NamedIndividual

Windows NtOpenProcess
type: Class
subclass of: OS API Trace Process
type: NamedIndividual
definition: Opens a handle to process obj and sets the access rights to this object.

Windows NtOpenThread
type: Class
subclass of: OS API Trace Thread
type: NamedIndividual
definition: Opens a handle to a thread object with the access specified.

Windows NtProtectVirtualMemory
type: Class
subclass of: OS API Allocate Memory
type: NamedIndividual

Windows NtQuerySystemTime
type: Class
subclass of: OS API Get System Time
type: NamedIndividual
definition: Returns current time in Coordinated Universal Time (UTC) 8-bytes format.

Windows NtReadFile
type: Class
subclass of: OS API Read File
type: NamedIndividual

Windows NtReadFileScatter
type: Class
subclass of: OS API Read File
type: NamedIndividual
definition: Reads specified block from file into multiple buffers. Each buffer must have one page length.

Windows NtResumeThread
type: Class
subclass of: OS API Resume Thread
type: NamedIndividual

Windows NtSetInformationFile Argument FileDispositionInformation
type: Class
subclass of: OS API Delete File
definition: Request to delete the file when it is closed or cancel a previously requested deletion.

Windows NtSetThreadContext
type: Class
subclass of: OS API Set Thread Context
type: NamedIndividual

Windows NtSuspendProcess
type: Class
subclass of: OS API Suspend Process

Windows NtSuspendThread
type: Class
subclass of: OS API Suspend Thread
type: NamedIndividual

Windows NtTerminateProcess
type: Class
subclass of: OS API Terminate Process
type: NamedIndividual

Windows NtWriteFile
type: Class
subclass of: OS API Write File
type: NamedIndividual

Windows NtWriteFileGather
type: Class
subclass of: OS API Write File
type: NamedIndividual
definition: Writes specified block of file with data from memory pages.

Windows NtWriteVirtualMemory
type: Class
subclass of: OS API Write Memory
type: NamedIndividual

Windows OpenProcess
type: Class
subclass of: OS API Trace Process
subclass of: Restriction
  on property: invokes
  some values from: Windows NtOpenProcess
type: NamedIndividual
invokes: Windows NtOpenProcess
definition: Opens an existing local process object.

Windows OpenThread
type: Class
subclass of: OS API Trace Thread
subclass of: Restriction
  on property: invokes
  some values from: Windows NtOpenThread
type: NamedIndividual
invokes: Windows NtOpenThread
definition: Opens an existing thread object.

Windows QueryPerformanceCounter
type: Class
subclass of: OS API Get System Time
subclass of: Restriction
  on property: invokes
  some values from: Windows NtQuerySystemTime
type: NamedIndividual
invokes: Windows NtQuerySystemTime
definition: Retrieves the current value of the performance counter, which is a high resolution (<1us) time stamp that can be used for time-interval measurements.

Windows ReadFile
type: Class
subclass of: OS API Read File
subclass of: Restriction
  on property: invokes
  some values from: Windows NtReadFile
subclass of: Restriction
  on property: invokes
  some values from: Windows NtReadFileScatter
type: NamedIndividual
invokes: Windows NtReadFile
invokes: Windows NtReadFileScatter
definition: Reads data from the specified file or input/output (I/O) device. Reads occur at the position specified by the file pointer if supported by the device.

Windows Registry
type: Class
subclass of: System Configuration Database
subclass of: Restriction
  on property: contains
  some values from: Windows Registry Key
type: NamedIndividual
contains: Windows Registry Key
definition: The Windows Registry is a hierarchical database that stores low-level settings for the Microsoft Windows operating system and for applications that opt to use the registry. The kernel, device drivers, services, Security Accounts Manager, and user interface can all use the registry. The registry also allows access to counters for profiling system performance.

Windows Registry Event
type: Class
subclass of: Digital Event
subclass of: Restriction
  on property: has-participant
  some values from: Windows Registry
definition: Events involving interactions with the Windows Registry, including keys, values, and associated security configurations.

Windows Registry Key
type: Class
subclass of: System Configuration Database Record
subclass of: Restriction
  on property: may-contain
  some values from: Windows Registry Key
subclass of: Restriction
  on property: may-contain
  some values from: Windows Registry Value
subclass of: Restriction
  on property: windows-registry-key
  some values from: string
type: NamedIndividual
may-contain: Windows Registry Value
definition: Windows Registry Keys are container objects similar to folders that contain subkeys and/or data entries called values. A key can be a 'Registry Hive' when it is root key of a logical group of keys, subkeys, and values that has a set of supporting files loaded into memory when the operating system is started or a user logs in.

Windows Registry Key Creation Event
type: Class
subclass of: Windows Registry Key Event
definition: An event where a new registry key is added to the Windows Registry, establishing a new hierarchical node for configuration.

Windows Registry Key Deletion Event
type: Class
subclass of: Windows Registry Key Event
definition: An event representing the removal of a registry key from the Windows Registry, including its hierarchical structure and associated metadata.

Windows Registry Key Event
type: Class
subclass of: Windows Registry Event
subclass of: Restriction
  on property: has-participant
  some values from: Windows Registry Key
definition: Events representing actions performed on Windows Registry keys, such as creation, modification, or deletion, which define hierarchical nodes for storing configuration data.

Windows Registry Key Export Event
type: Class
subclass of: Windows Registry Key Event
definition: An event representing the export of registry key data from the Windows Registry to an external file or format.

Windows Registry Key Import Event
type: Class
subclass of: Windows Registry Key Event
definition: An event where registry key data is imported into the Windows Registry from an external source.

Windows Registry Key Read Event
type: Class
subclass of: Windows Registry Key Event
definition: An event where a registry key is accessed to query its structure, properties, or associated metadata without modifying its state.

Windows Registry Key Renaming Event
type: Class
subclass of: Windows Registry Key Event
definition: An event where the name of a registry key is changed, altering its identifier within the registry hierarchy.

Windows Registry Key Restore Event
type: Class
subclass of: Windows Registry Key Event
definition: An event where a registry key is restored to a previous state using a backup or recovery mechanism.

Windows Registry Key Set Security Event
type: Class
subclass of: Windows Registry Key Event
definition: An event representing the application or modification of access controls or security settings to a registry key.

Windows Registry Key Update Event
type: Class
subclass of: Windows Registry Key Event
definition: An event where an existing registry key is updated or reconfigured, reflecting changes to its metadata or properties.

Windows Registry Value
type: Class
subclass of: System Configuration Database Record
subclass of: Restriction
  on property: contained-by
  some values from: Windows Registry Key
subclass of: Restriction
  on property: windows-registry-value
  some values from: string
type: NamedIndividual
contained-by: Windows Registry Key
definition: A Windows Registry Value is a data structure consisting of a name, type, data (as a pointer), and the length. Windows Registry Values are always associated with a Windows Registry Key. They store the actual configuration data for the operating system and the programs that run on the system.

Windows Registry Value Deletion Event
type: Class
subclass of: Windows Registry Value Event
definition: An event where a registry value is deleted from the Windows Registry, permanently removing its associated data.

Windows Registry Value Event
type: Class
subclass of: Windows Registry Event
subclass of: Restriction
  on property: has-participant
  some values from: Windows Registry Value
definition: Events representing actions performed on Windows Registry values, which store configuration data within registry keys.

Windows Registry Value Get Event
type: Class
subclass of: Windows Registry Value Event
definition: An event where the data of a registry value is retrieved, typically to read its configuration or state.

Windows Registry Value Set Event
type: Class
subclass of: Windows Registry Value Event
definition: An event where data is assigned to a registry value, either creating it or updating its existing content.

Windows Registry Value Update Event
type: Class
subclass of: Windows Registry Value Event
definition: An event indicating changes to the data or configuration of an existing registry value within the Windows Registry.

Windows ResumeThread
type: Class
subclass of: OS API Resume Thread
subclass of: Restriction
  on property: invokes
  some values from: Windows NtResumeThread
type: NamedIndividual
invokes: Windows NtResumeThread
definition: Decrements a thread's suspend count. When the suspend count is decremented to zero, the execution of the thread is resumed.

Windows SetThreadContext
type: Class
subclass of: OS API Set Thread Context
subclass of: Restriction
  on property: invokes
  some values from: Windows NtSetThreadContext
type: NamedIndividual
invokes: Windows NtSetThreadContext
definition: Sets the context for the specified thread.

Windows Shortcut File
type: Class
subclass of: Shortcut File
type: NamedIndividual
definition: A Microsoft Windows shortcut file.
alternative label: Shell Link

Windows SuspendThread
type: Class
subclass of: OS API Suspend Thread
subclass of: Restriction
  on property: invokes
  some values from: Windows NtSuspendThread
type: NamedIndividual
invokes: Windows NtSuspendThread
definition: Suspends the specified thread.

Windows TerminateProcess
type: Class
subclass of: OS API Terminate Process
subclass of: Restriction
  on property: invokes
  some values from: Windows NtTerminateProcess
type: NamedIndividual
invokes: Windows NtTerminateProcess
definition: Terminates the specified process and all of its threads.

Windows VirtualAllocEx
type: Class
subclass of: OS API Allocate Memory
subclass of: Restriction
  on property: invokes
  some values from: Windows NtAllocateVirtualMemory
subclass of: Restriction
  on property: invokes
  some values from: Windows NtProtectVirtualMemory
type: NamedIndividual
invokes: Windows NtAllocateVirtualMemory
invokes: Windows NtProtectVirtualMemory
definition: Reserves, commits, or changes the state of a region of memory within the virtual address space of a specified process. The function initializes the memory it allocates to zero.

Windows VirtualFree
type: Class
subclass of: OS API Free Memory
subclass of: Restriction
  on property: invokes
  some values from: Windows NtFreeVirtualMemory
type: NamedIndividual
invokes: Windows NtFreeVirtualMemory
definition: Releases, decommits, or releases and decommits a region of pages within the virtual address space of the calling process.

Windows VirtualProtectEx
type: Class
subclass of: OS API Allocate Memory
subclass of: Restriction
  on property: invokes
  some values from: Windows NtAllocateVirtualMemory
subclass of: Restriction
  on property: invokes
  some values from: Windows NtProtectVirtualMemory
type: NamedIndividual
invokes: Windows NtAllocateVirtualMemory
invokes: Windows NtProtectVirtualMemory
definition: Changes the protection on a region of committed pages in the virtual address space of a specified process.

Windows WriteFile
type: Class
subclass of: OS API Write File
subclass of: Restriction
  on property: invokes
  some values from: Windows NtWriteFile
subclass of: Restriction
  on property: invokes
  some values from: Windows NtWriteFileGather
type: NamedIndividual
invokes: Windows NtWriteFile
invokes: Windows NtWriteFileGather
definition: Writes data to the specified file or input/output (I/O) device.

Windows WriteProcessMemory
type: Class
subclass of: OS API Write Memory
subclass of: Restriction
  on property: invokes
  some values from: Windows NtFlushInstructionCache
subclass of: Restriction
  on property: invokes
  some values from: Windows NtProtectVirtualMemory
subclass of: Restriction
  on property: invokes
  some values from: Windows NtWriteVirtualMemory
type: NamedIndividual
invokes: Windows NtFlushInstructionCache
invokes: Windows NtProtectVirtualMemory
invokes: Windows NtWriteVirtualMemory
definition: Writes data to an area of memory in a specified process. The entire area to be written to must be accessible or the operation fails.

Wireless Access Point
type: Class
subclass of: Computer Network Node
subclass of: Restriction
  on property: contains
  some values from: RF Transmitter
type: NamedIndividual
contains: RF Transmitter
definition: In computer networking, a wireless access point (WAP), or more generally just access point (AP), is a networking hardware device that allows other Wi-Fi devices to connect to a wired network. The AP usually connects to a router (via a wired network) as a standalone device, but it can also be an integral component of the router itself. An AP is differentiated from a hotspot which is a physical location where Wi-Fi access is available.
alternative label: WAP

Wireless Router
type: Class
subclass of: Router
subclass of: Wireless Access Point
definition: A wireless router is a device that performs the functions of a router and also includes the functions of a wireless access point. It is used to provide access to the Internet or a private computer network. Depending on the manufacturer and model, it can function in a wired local area network, in a wireless-only LAN, or in a mixed wired and wireless network.

Write File
type: Class
subclass of: System Call
subclass of: Restriction
  on property: modifies
  some values from: File
type: NamedIndividual
modifies: File
definition: The write is one of the most basic routines provided by a Unix-like operating system kernel. It writes data from a buffer declared by the user to a given device, such as a file. This is the primary way to output data from a program by directly using a system call. The destination is identified by a numeric code. The data to be written, for instance a piece of text, is defined by a pointer and a size, given in number of bytes. write thus takes three arguments.

Write Memory
type: Class
subclass of: System Call
subclass of: Restriction
  on property: modifies
  some values from: Memory Block
type: NamedIndividual
modifies: Memory Block

Zero Client Computer
type: Class
subclass of: Thin Client Computer
definition: Zero client is also referred as ultra thin client, contains no moving parts but centralizes all processing and storage to just what is running on the server. As a result, it requires no local driver to install, no patch management, and no local operating system licensing fees or updates. The device consumes very little power and is tamper-resistant and completely incapable of storing any data locally, providing a more secure endpoint.

t-SNE Clustering
type: Class
subclass of: Projection-based Clustering
type: NamedIndividual
d3fend-id: D3A-TSC
definition: T-distributed Stochastic Neighbor Embedding (t-SNE) is a statistical method for visualizing high-dimensional data by giving each datapoint a location in a two or three-dimensional map.
kb-article: ## References Wikipedia. (n.d.). T-distributed stochastic neighbor embedding. [Link](https://en.wikipedia.org/wiki/T-distributed_stochastic_neighbor_embedding)

AMD64 Code Segment
type: NamedIndividual
type: Image Code Segment
type: Process Code Segment

ARM32 Code Segment
type: NamedIndividual
type: Image Code Segment
type: Process Code Segment

ASCII Domain Name
type: NamedIndividual
type: Domain Name

Adobe PDF File 1.3
type: NamedIndividual
type: Document File
may-contain: JavascriptFile

BSD Process
type: NamedIndividual
type: Process

Bash Script File
type: NamedIndividual
type: Executable Script

CCI-000015
type: NamedIndividual
type: CCI Control
broader: Account Locking
broader: Domain Account Monitoring
broader: Local Account Monitoring
member-of: CCICatalog v2022-04-05
date published: 2009-05-13T00:00:00
contributor: DISA FSO
definition: The organization employs automated mechanisms to support the information system account management functions.

CCI-000016
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Account Locking
date published: 2009-05-13T00:00:00
contributor: DISA FSO
definition: The information system automatically removes or disables temporary accounts after an organization-defined time period for each type of account.

CCI-000017
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Account Locking
date published: 2009-05-13T00:00:00
contributor: DISA FSO
definition: The information system automatically disables inactive accounts after an organization-defined time period.

CCI-000018
type: NamedIndividual
type: CCI Control
exactly: Domain Account Monitoring
member-of: CCICatalog v2022-04-05
date published: 2009-05-13T00:00:00
contributor: DISA FSO
definition: The information system automatically audits account creation actions.

CCI-000020
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
date published: 2009-09-14T00:00:00
contributor: DISA FSO
definition: The information system dynamically manages user privileges and associated access authorizations.

CCI-000022
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
date published: 2009-05-13T00:00:00
contributor: DISA FSO
definition: The information system enforces one or more organization-defined nondiscretionary access control policies over an organization-defined set of users and resources.

CCI-000025
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-14T00:00:00
contributor: DISA FSO
definition: The information system enforces information flow control using explicit security attributes on information, source, and destination objects as a basis for flow control decisions.

CCI-000027
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-05-13T00:00:00
contributor: DISA FSO
definition: The information system enforces dynamic information flow control based on organization-defined policies.

CCI-000029
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-05-13T00:00:00
contributor: DISA FSO
definition: The information system enforces organization-defined limitations on the embedding of data types within other data types.

CCI-000030
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-05-13T00:00:00
contributor: DISA FSO
definition: The information system enforces information flow control based on organization-defined metadata.

CCI-000032
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-14T00:00:00
contributor: DISA FSO
definition: The information system enforces information flow control using organization-defined security policy filters as a basis for flow control decisions for organization-defined information flows.

CCI-000034
type: NamedIndividual
type: CCI Control
broader: Inbound Traffic Filtering
broader: Outbound Traffic Filtering
member-of: CCICatalog v2022-04-05
date published: 2009-05-13T00:00:00
contributor: DISA FSO
definition: The information system provides the capability for a privileged administrator to enable/disable organization-defined security policy filters under organization-defined conditions.

CCI-000035
type: NamedIndividual
type: CCI Control
broader: Inbound Traffic Filtering
broader: Outbound Traffic Filtering
member-of: CCICatalog v2022-04-05
date published: 2009-09-14T00:00:00
contributor: DISA FSO
definition: The information system provides the capability for privileged administrators to configure the organization-defined security policy filters to support different security policies.

CCI-000037
type: NamedIndividual
type: CCI Control
broader: Local File Permissions
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2009-09-14T00:00:00
contributor: DISA FSO
definition: The organization implements separation of duties through assigned information system access authorizations.

CCI-000040
type: NamedIndividual
type: CCI Control
broader: Authorization Event Thresholding
broader: Local Account Monitoring
member-of: CCICatalog v2022-04-05
date published: 2009-09-14T00:00:00
contributor: DISA FSO
definition: The organization audits any use of privileged accounts, or roles, with access to organization-defined security functions or security-relevant information, when accessing other system functions.

CCI-000044
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Account Locking
date published: 2009-09-14T00:00:00
contributor: DISA FSO
definition: The information system enforces the organization-defined limit of consecutive invalid logon attempts by a user during the organization-defined time period.

CCI-000047
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Account Locking
date published: 2009-09-14T00:00:00
contributor: DISA FSO
definition: The information system delays next login prompt according to the organization-defined delay algorithm, when the maximum number of unsuccessful attempts is exceeded, automatically locks the account/node for an organization-defined time period or locks the account/node until released by an Administrator IAW organizational policy.

CCI-000056
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Account Locking
date published: 2009-09-14T00:00:00
contributor: DISA FSO
definition: The information system retains the session lock until the user reestablishes access using established identification and authentication procedures.

CCI-000057
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Account Locking
date published: 2009-05-19T00:00:00
contributor: DISA FSO
definition: The information system initiates a session lock after the organization-defined time period of inactivity.

CCI-000058
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Account Locking
date published: 2009-05-19T00:00:00
contributor: DISA FSO
definition: The information system provides the capability for users to directly initiate session lock mechanisms.

CCI-000060
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Account Locking
date published: 2009-05-19T00:00:00
contributor: DISA FSO
definition: The information system conceals, via the session lock, information previously visible on the display with a publicly viewable image.

CCI-000066
type: NamedIndividual
type: CCI Control
broader: Remote Terminal Session Detection
member-of: CCICatalog v2022-04-05
date published: 2009-09-14T00:00:00
contributor: DISA FSO
definition: The organization enforces requirements for remote connections to the information system.

CCI-000067
type: NamedIndividual
type: CCI Control
broader: Remote Terminal Session Detection
member-of: CCICatalog v2022-04-05
date published: 2009-09-14T00:00:00
contributor: DISA FSO
definition: The information system monitors remote access methods.

CCI-000068
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Encrypted Tunnels
date published: 2009-09-14T00:00:00
contributor: DISA FSO
definition: The information system implements cryptographic mechanisms to protect the confidentiality of remote access sessions.

CCI-000071
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Remote Terminal Session Detection
date published: 2009-05-19T00:00:00
contributor: DISA FSO
definition: The organization monitors for unauthorized remote connections to the information system on an organization-defined frequency.

CCI-000139
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: System Daemon Monitoring
date published: 2009-09-15T00:00:00
contributor: DISA FSO
definition: The information system alerts designated organization-defined personnel or roles in the event of an audit processing failure.

CCI-000143
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: System Daemon Monitoring
date published: 2009-05-20T00:00:00
contributor: DISA FSO
definition: The information system provides a warning when allocated audit record storage volume reaches an organization-defined percentage of maximum audit record storage capacity.

CCI-000144
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: System Daemon Monitoring
date published: 2009-05-20T00:00:00
contributor: DISA FSO
definition: The information system provides a real-time alert when organization-defined audit failure events occur.

CCI-000162
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Credential Hardening
date published: 2009-05-22T00:00:00
contributor: DISA FSO
definition: The information system protects audit information from unauthorized access.

CCI-000163
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Platform Hardening
narrower: System Configuration Permissions
date published: 2009-05-22T00:00:00
contributor: DISA FSO
definition: The information system protects audit information from unauthorized modification.

CCI-000164
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Platform Hardening
date published: 2009-05-22T00:00:00
contributor: DISA FSO
definition: The information system protects audit information from unauthorized deletion.

CCI-000185
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Credential Hardening
date published: 2009-09-15T00:00:00
contributor: DISA FSO
definition: The information system, for PKI-based authentication, validates certifications by constructing and verifying a certification path to an accepted trust anchor including checking certificate status information.

CCI-000186
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Credential Hardening
date published: 2009-09-15T00:00:00
contributor: DISA FSO
definition: The information system, for PKI-based authentication, enforces authorized access to the corresponding private key.

CCI-000187
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Credential Hardening
date published: 2009-09-15T00:00:00
contributor: DISA FSO
definition: The information system, for PKI-based authentication, maps the authenticated identity to the account of the individual or group.

CCI-000192
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Strong Password Policy
date published: 2009-09-15T00:00:00
contributor: DISA FSO
definition: The information system enforces password complexity by the minimum number of upper case characters used.

CCI-000193
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Strong Password Policy
date published: 2009-09-15T00:00:00
contributor: DISA FSO
definition: The information system enforces password complexity by the minimum number of lower case characters used.

CCI-000194
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Strong Password Policy
date published: 2009-09-15T00:00:00
contributor: DISA FSO
definition: The information system enforces password complexity by the minimum number of numeric characters used.

CCI-000195
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Strong Password Policy
date published: 2009-09-15T00:00:00
contributor: DISA FSO
definition: The information system, for password-based authentication, when new passwords are created, enforces that at least an organization-defined number of characters are changed.

CCI-000196
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Strong Password Policy
date published: 2009-09-15T00:00:00
contributor: DISA FSO
definition: The information system, for password-based authentication, stores only cryptographically-protected passwords.

CCI-000197
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Strong Password Policy
date published: 2009-09-15T00:00:00
contributor: DISA FSO
definition: The information system, for password-based authentication, transmits only cryptographically-protected passwords.

CCI-000198
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Strong Password Policy
date published: 2009-09-15T00:00:00
contributor: DISA FSO
definition: The information system enforces minimum password lifetime restrictions.

CCI-000199
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Strong Password Policy
date published: 2009-09-15T00:00:00
contributor: DISA FSO
definition: The information system enforces maximum password lifetime restrictions.

CCI-000200
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Strong Password Policy
date published: 2009-05-22T00:00:00
contributor: DISA FSO
definition: The information system prohibits password reuse for the organization-defined number of generations.

CCI-000205
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Strong Password Policy
date published: 2009-05-22T00:00:00
contributor: DISA FSO
definition: The information system enforces minimum password length.

CCI-000213
type: NamedIndividual
type: CCI Control
broader: Biometric Authentication
broader: Certificate-based Authentication
broader: Multi-factor Authentication
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2009-09-14T00:00:00
contributor: DISA FSO
definition: The information system enforces approved authorizations for logical access to information and system resources in accordance with applicable access control policies.

CCI-000218
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-14T00:00:00
contributor: DISA FSO
definition: The information system, when transferring information between different security domains, identifies information flows by data type specification and usage.

CCI-000219
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-14T00:00:00
contributor: DISA FSO
definition: The information system, when transferring information between different security domains, decomposes information into organization-defined policy-relevant subcomponents for submission to policy enforcement mechanisms.

CCI-000226
type: NamedIndividual
type: CCI Control
broader: Execution Isolation
member-of: CCICatalog v2022-04-05
date published: 2009-09-14T00:00:00
contributor: DISA FSO
definition: The information system provides the capability for a privileged administrator to configure organization-defined security policy filters to support different security policies.

CCI-000346
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Local File Permissions
narrower: User Account Permissions
date published: 2009-09-18T00:00:00
contributor: DISA FSO
definition: The organization employs automated mechanisms to enforce access restrictions.

CCI-000352
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Executable Allowlisting
narrower: Executable Denylisting
date published: 2009-09-18T00:00:00
contributor: DISA FSO
definition: The information system prevents the installation of organization-defined critical software programs that are not signed with a certificate that is recognized and approved by the organization.

CCI-000374
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Operating System Monitoring
date published: 2009-09-18T00:00:00
contributor: DISA FSO
definition: The organization employs automated mechanisms to respond to unauthorized changes to organization-defined configuration settings.

CCI-000381
type: NamedIndividual
type: CCI Control
broader: Platform Hardening
member-of: CCICatalog v2022-04-05
date published: 2009-09-18T00:00:00
contributor: DISA FSO
definition: The organization configures the information system to provide only essential capabilities.

CCI-000382
type: NamedIndividual
type: CCI Control
broader: Platform Hardening
member-of: CCICatalog v2022-04-05
date published: 2009-09-18T00:00:00
contributor: DISA FSO
definition: The organization configures the information system to prohibit or restrict the use of organization-defined functions, ports, protocols, and/or services.

CCI-000386
type: NamedIndividual
type: CCI Control
exactly: Executable Denylisting
member-of: CCICatalog v2022-04-05
date published: 2009-09-18T00:00:00
contributor: DISA FSO
definition: The organization employs automated mechanisms to prevent program execution on the information system in accordance with the organization-defined specifications.

CCI-000417
type: NamedIndividual
type: CCI Control
broader: Execution Isolation
broader: Network Isolation
member-of: CCICatalog v2022-04-05
date published: 2009-09-18T00:00:00
contributor: DISA FSO
definition: The organization disables network access by unauthorized components/devices or notifies designated organizational officials.

CCI-000663
type: NamedIndividual
type: CCI Control
broader: Execution Isolation
member-of: CCICatalog v2022-04-05
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The organization (or information system) enforces explicit rules governing the installation of software by users.

CCI-000764
type: NamedIndividual
type: CCI Control
broader: Biometric Authentication
broader: Certificate-based Authentication
broader: Multi-factor Authentication
broader: One-time Password
member-of: CCICatalog v2022-04-05
date published: 2009-09-17T00:00:00
contributor: DISA FSO
definition: The information system uniquely identifies and authenticates organizational users (or processes acting on behalf of organizational users).

CCI-000765
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Multi-factor Authentication
date published: 2009-09-17T00:00:00
contributor: DISA FSO
definition: The information system implements multifactor authentication for network access to privileged accounts.

CCI-000766
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Multi-factor Authentication
date published: 2009-09-17T00:00:00
contributor: DISA FSO
definition: The information system implements multifactor authentication for network access to non-privileged accounts.

CCI-000767
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Multi-factor Authentication
date published: 2009-09-17T00:00:00
contributor: DISA FSO
definition: The information system implements multifactor authentication for local access to privileged accounts.

CCI-000768
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Multi-factor Authentication
date published: 2009-09-17T00:00:00
contributor: DISA FSO
definition: The information system implements multifactor authentication for local access to non-privileged accounts.

CCI-000771
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Multi-factor Authentication
date published: 2009-09-17T00:00:00
contributor: DISA FSO
definition: The information system uses multifactor authentication for network access to privileged accounts where one of the factors is provided by a device separate from the information system being accessed.

CCI-000772
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Multi-factor Authentication
date published: 2009-09-17T00:00:00
contributor: DISA FSO
definition: The information system uses multifactor authentication for network access to non-privileged accounts where one of the factors is provided by a device separate from the information system being accessed.

CCI-000774
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: One-time Password
date published: 2009-09-17T00:00:00
contributor: DISA FSO
definition: The information system uses organization-defined replay-resistant authentication mechanisms for network access to privileged accounts.

CCI-000776
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: One-time Password
date published: 2009-09-17T00:00:00
contributor: DISA FSO
definition: The information system uses organization-defined replay-resistant authentication mechanisms for network access to non-privileged accounts.

CCI-000804
type: NamedIndividual
type: CCI Control
broader: Biometric Authentication
broader: Certificate-based Authentication
broader: Multi-factor Authentication
broader: One-time Password
member-of: CCICatalog v2022-04-05
date published: 2009-09-17T00:00:00
contributor: DISA FSO
definition: The information system uniquely identifies and authenticates non-organizational users (or processes acting on behalf of non-organizational users).

CCI-000831
type: NamedIndividual
type: CCI Control
broader: Credential Eviction
broader: Process Eviction
member-of: CCICatalog v2022-04-05
date published: 2009-09-18T00:00:00
contributor: DISA FSO
definition: The organization implements a configurable capability to automatically disable the information system if organization-defined security violations are detected.

CCI-000877
type: NamedIndividual
type: CCI Control
broader: Biometric Authentication
broader: Certificate-based Authentication
broader: Multi-factor Authentication
member-of: CCICatalog v2022-04-05
date published: 2009-09-18T00:00:00
contributor: DISA FSO
definition: The organization employs strong authenticators in the establishment of nonlocal maintenance and diagnostic sessions.

CCI-000880
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Operating System Monitoring
date published: 2009-09-18T00:00:00
contributor: DISA FSO
definition: The organization audits non-local maintenance and diagnostic sessions.

CCI-000884
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Credential Hardening
date published: 2009-09-18T00:00:00
contributor: DISA FSO
definition: The organization protects nonlocal maintenance sessions by employing organization-defined authenticators that are replay resistant.

CCI-000888
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Encrypted Tunnels
date published: 2009-09-18T00:00:00
contributor: DISA FSO
definition: The organization employs cryptographic mechanisms to protect the integrity and confidentiality of non-local maintenance and diagnostic communications.

CCI-001009
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: File Encryption
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system uses cryptographic mechanisms to protect and restrict access to information on portable digital media.

CCI-001019
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Disk Encryption
narrower: File Encryption
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The organization employs cryptographic mechanisms to protect information in storage.

CCI-001067
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Platform Hardening
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system implements privileged access authorization to organization-identified information system components for selected organization-defined vulnerability scanning activities.

CCI-001069
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Executable Allowlisting
narrower: Executable Denylisting
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The organization employs automated mechanisms to detect the presence of unauthorized software on organizational information systems and notify designated organizational officials in accordance with the organization-defined frequency.

CCI-001082
type: NamedIndividual
type: CCI Control
broader: Local File Permissions
broader: System Configuration Permissions
member-of: CCICatalog v2022-04-05
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system separates user functionality (including user interface services) from information system management functionality.

CCI-001083
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Local File Permissions
narrower: System Configuration Permissions
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system prevents the presentation of information system management-related functionality at an interface for non-privileged users.

CCI-001084
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: System Configuration Permissions
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system isolates security functions from nonsecurity functions.

CCI-001085
type: NamedIndividual
type: CCI Control
broader: Hardware-based Process Isolation
member-of: CCICatalog v2022-04-05
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system utilizes underlying hardware separation mechanisms to implement security function isolation.

CCI-001086
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: System Configuration Permissions
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system isolates security functions enforcing access and information flow control from both nonsecurity functions and from other security functions.

CCI-001087
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: System Configuration Permissions
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The organization implements an information system isolation boundary to minimize the number of nonsecurity functions included within the boundary containing security functions.

CCI-001089
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: System Configuration Permissions
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The organization implements security functions as a layered structure minimizing interactions between layers of the design and avoiding any dependence by lower layers on the functionality or correctness of higher layers.

CCI-001090
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Network Traffic Filtering
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system prevents unauthorized and unintended information transfer via shared system resources.

CCI-001092
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system protects against or limits the effects of the organization-defined or referenced types of denial of service attacks.

CCI-001094
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system restricts the ability of individuals to launch organization-defined denial of service attacks against other information systems.

CCI-001096
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Local File Permissions
narrower: System Configuration Permissions
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system limits the use of resources by priority.

CCI-001100
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system prevents public access into the organization's internal networks except as appropriately mediated by managed interfaces employing boundary protection devices.

CCI-001109
type: NamedIndividual
type: CCI Control
exactly: Inbound Traffic Filtering
exactly: Outbound Traffic Filtering
member-of: CCICatalog v2022-04-05
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system at managed interfaces denies network communications traffic by default and allows network communications traffic by exception (i.e., deny all, permit by exception).

CCI-001111
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system prevents remote devices that have established a non-remote connection with the system from communicating outside of that communications path with resources in external networks.

CCI-001115
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system, at managed interfaces, denies network traffic and audits internal users (or malicious code) posing a threat to external information systems.

CCI-001117
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system checks incoming communications to ensure the communications are coming from an authorized source and routed to an authorized destination.

CCI-001118
type: NamedIndividual
type: CCI Control
broader: Network Isolation
member-of: CCICatalog v2022-04-05
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system implements host-based boundary protection mechanisms for servers, workstations, and mobile devices.

CCI-001124
type: NamedIndividual
type: CCI Control
broader: Broadcast Domain Isolation
member-of: CCICatalog v2022-04-05
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system prevents discovery of specific system components composing a managed interface.

CCI-001125
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system enforces adherence to protocol format.

CCI-001127
type: NamedIndividual
type: CCI Control
broader: Encrypted Tunnels
member-of: CCICatalog v2022-04-05
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system protects the integrity of transmitted information.

CCI-001128
type: NamedIndividual
type: CCI Control
broader: Encrypted Tunnels
member-of: CCICatalog v2022-04-05
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The organization employs cryptographic mechanisms to recognize changes to information during transmission unless otherwise protected by alternative physical measures.

CCI-001133
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Session Duration Analysis
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system terminates the network connection associated with a communications session at the end of the session or after an organization-defined time period of inactivity.

CCI-001144
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Disk Encryption
narrower: File Encryption
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system implements required cryptographic protections using cryptographic modules that comply with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.

CCI-001145
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Disk Encryption
narrower: File Encryption
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The organization employs, at a minimum, FIPS-validated cryptography to protect unclassified information.

CCI-001146
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Disk Encryption
narrower: File Encryption
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The organization employs NSA-approved cryptography to protect classified information.

CCI-001147
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Disk Encryption
narrower: File Encryption
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The organization employs, at a minimum, FIPS-validated cryptography to protect information when such information must be separated from individuals who have the necessary clearances yet lack the necessary access approvals.

CCI-001150
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Remote Terminal Session Detection
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system prohibits remote activation of collaborative computing devices, excluding the organization-defined exceptions where remote activation is to be allowed.

CCI-001166
type: NamedIndividual
type: CCI Control
broader: Dynamic Analysis
broader: Emulated File Analysis
broader: File Content Rules
member-of: CCICatalog v2022-04-05
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system identifies organization-defined unacceptable mobile code.

CCI-001169
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Executable Denylisting
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system prevents the download of organization-defined unacceptable mobile code.

CCI-001170
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Executable Denylisting
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system prevents the automatic execution of mobile code in organization-defined software applications.

CCI-001178
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Domain Trust Policy
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system provides additional data origin authentication artifacts along with the authoritative name resolution data the system returns in response to external name/address resolution queries.

CCI-001185
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Authentication Cache Invalidation
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system invalidates session identifiers upon user logout or other session termination.

CCI-001199
type: NamedIndividual
type: CCI Control
broader: Disk Encryption
broader: File Content Rules
broader: File Encryption
broader: File Hashing
broader: Local File Permissions
member-of: CCICatalog v2022-04-05
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system protects the confidentiality and/or integrity of organization-defined information at rest.

CCI-001200
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Disk Encryption
narrower: File Encryption
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The organization employs cryptographic mechanisms to prevent unauthorized disclosure of information at rest unless otherwise protected by alternative physical measures.

CCI-001210
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Driver Load Integrity Checking
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system, at organization-defined information system components, loads and executes the operating environment from hardware-enforced, read-only media.

CCI-001211
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Application Configuration Hardening
date published: 2009-09-21T00:00:00
contributor: DISA FSO
definition: The information system, at organization-defined information system components, loads and executes organization-defined applications from hardware-enforced, read-only media.

CCI-001233
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Software Update
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The organization employs automated mechanisms on an organization-defined frequency to determine the state of information system components with regard to flaw remediation.

CCI-001237
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Software Update
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The organization employs automated patch management tools to facilitate flaw remediation to organization-defined information system components.

CCI-001239
type: NamedIndividual
type: CCI Control
broader: File Analysis
broader: Network Traffic Analysis
broader: Platform Monitoring
broader: Process Analysis
member-of: CCICatalog v2022-04-05
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The organization employs malicious code protection mechanisms at information system entry and exit points to detect and eradicate malicious code transported by electronic mail, electronic mail attachments, web accesses, removable media, or other common means or inserted through the exploitation of information system vulnerabilities.

CCI-001242
type: NamedIndividual
type: CCI Control
broader: Dynamic Analysis
broader: Emulated File Analysis
broader: File Content Rules
member-of: CCICatalog v2022-04-05
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The organization configures malicious code protection mechanisms to perform real-time scans of files from external sources at endpoints as the files are downloaded, opened, or executed in accordance with organizational security policy.

CCI-001262
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The information system monitors inbound and outbound communications for unusual or unauthorized activities or conditions.

CCI-001297
type: NamedIndividual
type: CCI Control
broader: Driver Load Integrity Checking
broader: File Hashing
broader: Pointer Authentication
broader: TPM Boot Integrity
member-of: CCICatalog v2022-04-05
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The information system detects unauthorized changes to software and information.

CCI-001305
type: NamedIndividual
type: CCI Control
broader: Message Authentication
broader: Sender MTA Reputation Analysis
broader: Sender Reputation Analysis
broader: Transfer Agent Authentication
member-of: CCICatalog v2022-04-05
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The organization employs spam protection mechanisms at information system entry and exit points to detect and take action on unsolicited messages transported by electronic mail, electronic mail attachments, web accesses, removable media, or other common means.

CCI-001310
type: NamedIndividual
type: CCI Control
broader: Database Query String Analysis
member-of: CCICatalog v2022-04-05
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The information system checks the validity of organization-defined inputs.

CCI-001350
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: File Encryption
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The information system implements cryptographic mechanisms to protect the integrity of audit information.

CCI-001352
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The organization protects the audit records of non-local accesses to privileged accounts and the execution of privileged functions.

CCI-001356
type: NamedIndividual
type: CCI Control
exactly: Authentication Event Thresholding
exactly: Authorization Event Thresholding
member-of: CCICatalog v2022-04-05
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The organization monitors for atypical usage of information system accounts.

CCI-001368
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The information system enforces approved authorizations for controlling the flow of information within the system based on organization-defined information flow control policies.

CCI-001372
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The information system, when transferring information between different security domains, implements organization-defined security policy filters requiring fully enumerated formats that restrict data structure and content.

CCI-001373
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The information system, when transferring information between different security domains, examines the information for the presence of organization-defined unsanctioned information.

CCI-001374
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The information system, when transferring information between different security domains, prohibits the transfer of organization-defined unsanctioned information in accordance with the organization-defined security policy.

CCI-001376
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Domain Trust Policy
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The information system uniquely identifies source domains for information transfer.

CCI-001377
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Domain Trust Policy
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The information system uniquely authenticates source domains for information transfer.

CCI-001399
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The information system supports and maintains the binding of organization-defined security attributes to information in storage.

CCI-001400
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The information system supports and maintains the binding of organization-defined security attributes to information in process.

CCI-001401
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2009-09-22T00:00:00
contributor: DISA FSO
definition: The information system supports and maintains the binding of organization-defined security attributes to information in transmission.

CCI-001403
type: NamedIndividual
type: CCI Control
exactly: Domain Account Monitoring
member-of: CCICatalog v2022-04-05
date published: 2009-09-24T00:00:00
contributor: DISA FSO
definition: The information system automatically audits account modification actions.

CCI-001404
type: NamedIndividual
type: CCI Control
exactly: Domain Account Monitoring
member-of: CCICatalog v2022-04-05
date published: 2009-09-24T00:00:00
contributor: DISA FSO
definition: The information system automatically audits account disabling actions.

CCI-001405
type: NamedIndividual
type: CCI Control
exactly: Domain Account Monitoring
member-of: CCICatalog v2022-04-05
date published: 2009-09-24T00:00:00
contributor: DISA FSO
definition: The information system automatically audits account removal actions.

CCI-001414
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-24T00:00:00
contributor: DISA FSO
definition: The information system enforces approved authorizations for controlling the flow of information between interconnected systems based on organization-defined information flow control policies.

CCI-001424
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2009-09-25T00:00:00
contributor: DISA FSO
definition: The information system dynamically associates security attributes with organization-defined subjects in accordance with organization-defined security policies as information is created and combined.

CCI-001425
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2009-09-25T00:00:00
contributor: DISA FSO
definition: The information system provides authorized individuals (or processes acting on behalf of individuals) the capability to change the value of associated security attributes.

CCI-001426
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2009-09-25T00:00:00
contributor: DISA FSO
definition: The information system maintains the binding of security attributes to information with sufficient assurance that the information--attribute association can be used as the basis for automated policy actions.

CCI-001427
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2009-09-25T00:00:00
contributor: DISA FSO
definition: The information system allows authorized users to associate security attributes with information.

CCI-001428
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2009-09-25T00:00:00
contributor: DISA FSO
definition: The information system displays security attributes in human-readable form on each object that the system transmits to output devices to identify organization-identified special dissemination, handling, or distribution instructions using organization-identified human-readable, standard naming conventions.

CCI-001436
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2009-09-25T00:00:00
contributor: DISA FSO
definition: The organization disables organization-defined networking protocols within the information system deemed to be nonsecure except for explicitly identified components in support of specific operational requirements.

CCI-001452
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Account Locking
date published: 2009-05-25T00:00:00
contributor: DISA FSO
definition: The information system enforces the organization-defined time period during which the limit of consecutive invalid access attempts by a user is counted.

CCI-001453
type: NamedIndividual
type: CCI Control
exactly: Encrypted Tunnels
member-of: CCICatalog v2022-04-05
date published: 2009-09-29T00:00:00
contributor: DISA FSO
definition: The information system implements cryptographic mechanisms to protect the integrity of remote access sessions.

CCI-001454
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Remote Terminal Session Detection
date published: 2009-09-29T00:00:00
contributor: DISA FSO
definition: The organization ensures that remote sessions for accessing an organization-defined list of security functions and security-relevant information are audited.

CCI-001493
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
date published: 2009-09-29T00:00:00
contributor: DISA FSO
definition: The information system protects audit tools from unauthorized access.

CCI-001494
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Platform Hardening
narrower: System Configuration Permissions
date published: 2009-09-29T00:00:00
contributor: DISA FSO
definition: The information system protects audit tools from unauthorized modification.

CCI-001495
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Platform Hardening
date published: 2009-09-29T00:00:00
contributor: DISA FSO
definition: The information system protects audit tools from unauthorized deletion.

CCI-001496
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: File Encryption
date published: 2009-09-29T00:00:00
contributor: DISA FSO
definition: The information system implements cryptographic mechanisms to protect the integrity of audit tools.

CCI-001499
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: System Configuration Permissions
narrower: User Account Permissions
date published: 2009-09-29T00:00:00
contributor: DISA FSO
definition: The organization limits privileges to change software resident within software libraries.

CCI-001555
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Domain Trust Policy
date published: 2010-05-11T00:00:00
contributor: DISA FSO
definition: The information system uniquely identifies destination domains for information transfer.

CCI-001556
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Domain Trust Policy
date published: 2010-05-11T00:00:00
contributor: DISA FSO
definition: The information system uniquely authenticates destination domains for information transfer.

CCI-001557
type: NamedIndividual
type: CCI Control
broader: Network Traffic Analysis
member-of: CCICatalog v2022-04-05
date published: 2010-05-11T00:00:00
contributor: DISA FSO
definition: The information system tracks problems associated with the information transfer.

CCI-001574
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2010-05-11T00:00:00
contributor: DISA FSO
definition: The information system rejects or delays, as defined by the organization, network traffic which exceed the organization-defined thresholds.

CCI-001589
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Operating System Monitoring
date published: 2010-05-12T00:00:00
contributor: DISA FSO
definition: The organization incorporates detection of unauthorized, security-relevant configuration changes into the organization‚Äôs incident response capability to ensure they are tracked.

CCI-001619
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Strong Password Policy
date published: 2010-05-12T00:00:00
contributor: DISA FSO
definition: The information system enforces password complexity by the minimum number of special characters used.

CCI-001632
type: NamedIndividual
type: CCI Control
exactly: Encrypted Tunnels
member-of: CCICatalog v2022-04-05
date published: 2010-05-12T00:00:00
contributor: DISA FSO
definition: The organization protects nonlocal maintenance sessions by separating the maintenance session from other network sessions with the information system by either physically separated communications paths or logically separated communications paths based upon encryption.

CCI-001662
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Dynamic Analysis
narrower: Emulated File Analysis
narrower: File Content Rules
date published: 2010-05-12T00:00:00
contributor: DISA FSO
definition: The information system takes organization-defined corrective action when organization-defined unacceptable mobile code is identified.

CCI-001668
type: NamedIndividual
type: CCI Control
broader: File Analysis
broader: Network Traffic Analysis
broader: Platform Monitoring
broader: Process Analysis
member-of: CCICatalog v2022-04-05
date published: 2010-05-12T00:00:00
contributor: DISA FSO
definition: The organization employs malicious code protection mechanisms at workstations, servers, or mobile computing devices on the network to detect and eradicate malicious code transported by electronic mail, electronic mail attachments, web accesses, removable media, or other common means or inserted through the exploitation of information system vulnerabilities.

CCI-001677
type: NamedIndividual
type: CCI Control
broader: Message Authentication
broader: Sender MTA Reputation Analysis
broader: Sender Reputation Analysis
broader: Transfer Agent Authentication
member-of: CCICatalog v2022-04-05
date published: 2010-05-12T00:00:00
contributor: DISA FSO
definition: The organization employs spam protection mechanisms at workstations, servers, or mobile computing devices on the network to detect and take action on unsolicited messages transported by electronic mail, electronic mail attachments, web accesses, removable media, or other common means.

CCI-001682
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Account Locking
date published: 2011-05-03T00:00:00
contributor: DISA FSO
definition: The information system automatically removes or disables emergency accounts after an organization-defined time period for each type of account.

CCI-001683
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Domain Account Monitoring
date published: 2011-05-03T00:00:00
contributor: DISA FSO
definition: The information system notifies organization-defined personnel or roles for account creation actions.

CCI-001684
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Domain Account Monitoring
date published: 2011-05-03T00:00:00
contributor: DISA FSO
definition: The information system notifies organization-defined personnel or roles for account modification actions.

CCI-001685
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Domain Account Monitoring
date published: 2011-05-03T00:00:00
contributor: DISA FSO
definition: The information system notifies organization-defined personnel or roles for account disabling actions.

CCI-001686
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Domain Account Monitoring
date published: 2011-05-03T00:00:00
contributor: DISA FSO
definition: The information system notifies organization-defined personnel or roles for account removal actions.

CCI-001695
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Executable Denylisting
date published: 2011-10-07T00:00:00
contributor: DISA FSO
definition: The information system prevents the execution of organization-defined unacceptable mobile code.

CCI-001744
type: NamedIndividual
type: CCI Control
broader: Operating System Monitoring
member-of: CCICatalog v2022-04-05
date published: 2013-02-28T00:00:00
contributor: DISA FSO
definition: The information system implements organization-defined security responses automatically if baseline configurations are changed in an unauthorized manner.

CCI-001749
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Executable Allowlisting
narrower: Executable Denylisting
date published: 2013-02-28T00:00:00
contributor: DISA FSO
definition: The information system prevents the installation of organization-defined software components without verification the software component has been digitally signed using a certificate that is recognized and approved by the organization.

CCI-001762
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: System Configuration Permissions
date published: 2013-02-28T00:00:00
contributor: DISA FSO
definition: The organization disables organization-defined functions, ports, protocols, and services within the information system deemed to be unnecessary and/or nonsecure.

CCI-001764
type: NamedIndividual
type: CCI Control
broader: Executable Allowlisting
broader: Executable Denylisting
member-of: CCICatalog v2022-04-05
date published: 2013-02-28T00:00:00
contributor: DISA FSO
definition: The information system prevents program execution in accordance with organization-defined policies regarding software program usage and restrictions, and/or rules authorizing the terms and conditions of software program usage.

CCI-001767
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Executable Denylisting
date published: 2013-02-28T00:00:00
contributor: DISA FSO
definition: The organization employs an allow-all, deny-by-exception policy to prohibit the execution of unauthorized software programs on the information system.

CCI-001774
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Executable Allowlisting
date published: 2013-02-28T00:00:00
contributor: DISA FSO
definition: The organization employs a deny-all, permit-by-exception policy to allow the execution of authorized software programs on the information system.

CCI-001811
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: File Analysis
date published: 2013-03-01T00:00:00
contributor: DISA FSO
definition: The information system alerts organization-defined personnel or roles when the unauthorized installation of software is detected.

CCI-001812
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Executable Allowlisting
narrower: Executable Denylisting
date published: 2013-03-01T00:00:00
contributor: DISA FSO
definition: The information system prohibits user installation of software without explicit privileged status.

CCI-001813
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-03-01T00:00:00
contributor: DISA FSO
definition: The information system enforces access restrictions.

CCI-001855
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: System Daemon Monitoring
date published: 2013-03-14T00:00:00
contributor: DISA FSO
definition: The information system provides a warning to organization-defined personnel, roles, and/or locations within an organization-defined time period when allocated audit record storage volume reaches an organization-defined percentage of repository maximum audit record storage capacity.

CCI-001858
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: System Daemon Monitoring
date published: 2013-03-14T00:00:00
contributor: DISA FSO
definition: The information system provides a real-time alert in an organization-defined real-time period to organization-defined personnel, roles, and/or locations when organization-defined audit failure events requiring real-time alerts occur.

CCI-001936
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Multi-factor Authentication
date published: 2013-05-03T00:00:00
contributor: DISA FSO
definition: The information system implements multifactor authentication for network access to privileged accounts such that one of the factors is provided by a device separate from the system gaining access.

CCI-001937
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Multi-factor Authentication
date published: 2013-05-03T00:00:00
contributor: DISA FSO
definition: The device used in the information system implementation of multifactor authentication for network access to privileged accounts meets organization-defined strength of mechanism requirements.

CCI-001941
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: One-time Password
date published: 2013-05-03T00:00:00
contributor: DISA FSO
definition: The information system implements replay-resistant authentication mechanisms for network access to privileged accounts.

CCI-001953
type: NamedIndividual
type: CCI Control
broader: Biometric Authentication
broader: Certificate-based Authentication
member-of: CCICatalog v2022-04-05
date published: 2013-05-03T00:00:00
contributor: DISA FSO
definition: The information system accepts Personal Identity Verification (PIV) credentials.

CCI-001954
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Biometric Authentication
narrower: Certificate-based Authentication
date published: 2013-05-03T00:00:00
contributor: DISA FSO
definition: The information system electronically verifies Personal Identity Verification (PIV) credentials.

CCI-001957
type: NamedIndividual
type: CCI Control
broader: One-time Password
member-of: CCICatalog v2022-04-05
date published: 2013-05-03T00:00:00
contributor: DISA FSO
definition: The information system implements organization-defined out-of-band authentication under organization-defined conditions.

CCI-001991
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Certificate-based Authentication
date published: 2013-05-03T00:00:00
contributor: DISA FSO
definition: The information system, for PKI-based authentication, implements a local cache of revocation data to support path discovery and validation in case of inability to access revocation information via the network.

CCI-002005
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Biometric Authentication
date published: 2013-05-03T00:00:00
contributor: DISA FSO
definition: The information system, for biometric-based authentication, employs mechanisms that satisfy organization-defined biometric quality requirements.

CCI-002009
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Biometric Authentication
narrower: Certificate-based Authentication
date published: 2013-05-03T00:00:00
contributor: DISA FSO
definition: The information system accepts Personal Identity Verification (PIV) credentials from other federal agencies.

CCI-002010
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Biometric Authentication
narrower: Certificate-based Authentication
date published: 2013-05-03T00:00:00
contributor: DISA FSO
definition: The information system electronically verifies Personal Identity Verification (PIV) credentials from other federal agencies.

CCI-002015
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Biometric Authentication
narrower: Certificate-based Authentication
date published: 2013-05-03T00:00:00
contributor: DISA FSO
definition: The information system accepts Personal Identity Verification-I (PIV-I) credentials.

CCI-002016
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Biometric Authentication
narrower: Certificate-based Authentication
date published: 2013-05-03T00:00:00
contributor: DISA FSO
definition: The information system electronically verifies Personal Identity Verification-I (PIV-I) credentials.

CCI-002041
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Strong Password Policy
date published: 2013-05-03T00:00:00
contributor: DISA FSO
definition: The information system allows the use of a temporary password for system logons with an immediate change to a permanent password.

CCI-002145
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: User Account Permissions
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system enforces organization-defined circumstances and/or usage conditions for organization-defined information system accounts.

CCI-002165
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system enforces organization-defined discretionary access control policies over defined subjects and objects.

CCI-002169
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system enforces a role-based access control policy over defined subjects and objects.

CCI-002178
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: System Call Filtering
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system enforces the revocation of access authorizations resulting from changes to the security attributes of subjects based on organization-defined rules governing the timing of revocations of access authorizations.

CCI-002179
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: System Call Filtering
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system enforces the revocation of access authorizations resulting from changes to the security attributes of objects based on organization-defined rules governing the timing of revocations of access authorizations.

CCI-002201
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Domain Trust Policy
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system, when transferring information between different security domains, uses organization-defined data type identifiers to validate data essential for information flow decisions.

CCI-002205
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Domain Trust Policy
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system uniquely identifies and authenticates source by organization, system, application, and/or individual for information transfer.

CCI-002207
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Domain Trust Policy
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system uniquely identifies and authenticates destination by organization, system, application, and/or individual for information transfer.

CCI-002211
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system, when transferring information between different security domains, applies the same security policy filtering to metadata as it applies to data payloads.

CCI-002218
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Domain Trust Policy
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system provides access from a single device to computing platforms, applications, or data residing on multiple different security domains, while preventing any information flow between the different security domains.

CCI-002233
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Executable Denylisting
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system prevents organization-defined software from executing at higher privilege levels than users executing the software.

CCI-002235
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: System Configuration Permissions
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system prevents non-privileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures.

CCI-002238
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Account Locking
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system automatically locks the account or node for either an organization-defined time period, until the locked account or node is released by an administrator, or delays the next logon prompt according to the organization-defined delay algorithm when the maximum number of unsuccessful logon attempts is exceeded.

CCI-002262
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The organization provides the means to associate organization-defined types of security attributes having organization-defined security attribute values with information in storage.

CCI-002263
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The organization provides the means to associate organization-defined types of security attributes having organization-defined security attribute values with information in process.

CCI-002264
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The organization provides the means to associate organization-defined types of security attributes having organization-defined security attribute values with information in transmission.

CCI-002272
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system dynamically associates security attributes with organization-defined objects in accordance with organization-defined security policies as information is created and combined.

CCI-002277
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system provides authorized individuals (or processes acting on behalf of individuals) the capability to define the value of associated security attributes.

CCI-002281
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system maintains the association of organization-defined security attributes to organization-defined subjects.

CCI-002282
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system maintains the association of organization-defined security attributes to organization-defined objects.

CCI-002283
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system maintains the integrity of organization-defined security attributes associated with organization-defined subjects.

CCI-002284
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system maintains the integrity of organization-defined security attributes associated with organization-defined objects.

CCI-002289
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system supports the association of organization-defined security attributes with organization-defined subjects by authorized individuals (or processes acting on behalf of individuals).

CCI-002290
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system supports the association of organization-defined security attributes with organization-defined objects by authorized individuals (or processes acting on behalf of individuals).

CCI-002302
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system implements organization-defined techniques or technologies with an organization-defined level of assurance in associating security attributes to information.

CCI-002306
type: NamedIndividual
type: CCI Control
broader: System Configuration Permissions
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system provides authorized individuals the capability to define or change the type of security attributes available for association with subjects.

CCI-002307
type: NamedIndividual
type: CCI Control
broader: System Configuration Permissions
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system provides authorized individuals the capability to define or change the value of security attributes available for association with subjects.

CCI-002308
type: NamedIndividual
type: CCI Control
broader: System Configuration Permissions
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system provides authorized individuals the capability to define or change the type of security attributes available for association with objects.

CCI-002309
type: NamedIndividual
type: CCI Control
broader: System Configuration Permissions
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The information system provides authorized individuals the capability to define or change the value of security attributes available for association with objects.

CCI-002322
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Remote Terminal Session Detection
date published: 2013-06-24T00:00:00
contributor: DISA FSO
definition: The organization provides the capability to expeditiously disconnect or disable remote access to the information system within the organization-defined time period.

CCI-002346
type: NamedIndividual
type: CCI Control
broader: Database Query String Analysis
broader: Disk Encryption
broader: File Encryption
member-of: CCICatalog v2022-04-05
date published: 2013-06-25T00:00:00
contributor: DISA FSO
definition: The organization employs organization-defined data mining prevention techniques for organization-defined data storage objects to adequately protect against data mining.

CCI-002347
type: NamedIndividual
type: CCI Control
broader: File Access Pattern Analysis
broader: Input Device Analysis
broader: Resource Access Pattern Analysis
broader: User Data Transfer Analysis
member-of: CCICatalog v2022-04-05
date published: 2013-06-25T00:00:00
contributor: DISA FSO
definition: The organization employs organization-defined data mining detection techniques for organization-defined data storage objects to adequately detect data mining attempts.

CCI-002353
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-25T00:00:00
contributor: DISA FSO
definition: The information system transmits organization-defined access authorization information using organization-defined security safeguards to organization-defined information systems which enforce access control decisions.

CCI-002355
type: NamedIndividual
type: CCI Control
broader: User Account Permissions
member-of: CCICatalog v2022-04-05
date published: 2013-06-25T00:00:00
contributor: DISA FSO
definition: The information system enforces access control decisions based on organization-defined security attributes that do not include the identity of the user or process acting on behalf of the user.

CCI-002357
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: User Account Permissions
date published: 2013-06-25T00:00:00
contributor: DISA FSO
definition: The information system implements a reference monitor for organization-defined access control policies that is tamperproof.

CCI-002358
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: User Account Permissions
date published: 2013-06-25T00:00:00
contributor: DISA FSO
definition: The information system implements a reference monitor for organization-defined access control policies that is always invoked.

CCI-002359
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: User Account Permissions
date published: 2013-06-25T00:00:00
contributor: DISA FSO
definition: The information system implements a reference monitor for organization-defined access control policies that is small enough to be subject to analysis and testing, the completeness of which can be assured.

CCI-002361
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Process Termination
date published: 2013-06-26T00:00:00
contributor: DISA FSO
definition: The information system automatically terminates a user session after organization-defined conditions or trigger events requiring session disconnect.

CCI-002363
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Process Termination
date published: 2013-06-26T00:00:00
contributor: DISA FSO
definition: The information system provides a logout capability for user-initiated communications sessions whenever authentication is used to gain access to organization-defined information resources.

CCI-002364
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Process Termination
date published: 2013-06-26T00:00:00
contributor: DISA FSO
definition: The information system displays an explicit logout message to users indicating the reliable termination of authenticated communications sessions.

CCI-002381
type: NamedIndividual
type: CCI Control
broader: Hardware-based Process Isolation
broader: Kernel-based Process Isolation
member-of: CCICatalog v2022-04-05
date published: 2013-07-02T00:00:00
contributor: DISA FSO
definition: The organization minimizes the number of nonsecurity functions included within the isolation boundary containing security functions.

CCI-002382
type: NamedIndividual
type: CCI Control
broader: Hardware-based Process Isolation
broader: Kernel-based Process Isolation
member-of: CCICatalog v2022-04-05
date published: 2013-07-02T00:00:00
contributor: DISA FSO
definition: The organization implements security functions as largely independent modules that maximize internal cohesiveness within modules and minimize coupling between modules.

CCI-002384
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Network Traffic Filtering
date published: 2013-07-02T00:00:00
contributor: DISA FSO
definition: The information system prevents unauthorized information transfer via shared resources in accordance with organization-defined procedures when system processing explicitly switches between different information classification levels or security categories.

CCI-002385
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2013-07-02T00:00:00
contributor: DISA FSO
definition: The information system protects against or limits the effects of organization-defined types of denial of service attacks by employing organization-defined security safeguards.

CCI-002394
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: System Configuration Permissions
date published: 2013-07-02T00:00:00
contributor: DISA FSO
definition: The information system protects the availability of resources by allocating organization-defined resources based on priority, quota, and/or organization-defined security safeguards.

CCI-002397
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2013-07-02T00:00:00
contributor: DISA FSO
definition: The information system, in conjunction with a remote device, prevents the device from simultaneously establishing non-remote connections with the system and communicating via some other connection to resources in external networks.

CCI-002400
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Outbound Traffic Filtering
date published: 2013-07-02T00:00:00
contributor: DISA FSO
definition: The information system audits the identity of internal users associated with denied outgoing communications traffic posing a threat to external information systems.

CCI-002403
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2013-07-02T00:00:00
contributor: DISA FSO
definition: The information system only allows incoming communications from organization-defined authorized sources routed to organization-defined authorized destinations.

CCI-002409
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Inbound Traffic Filtering
narrower: Outbound Traffic Filtering
date published: 2013-07-02T00:00:00
contributor: DISA FSO
definition: The information system blocks both inbound and outbound communications traffic between organization-defined communication clients that are independently configured by end users and external service providers.

CCI-002411
type: NamedIndividual
type: CCI Control
broader: Hardware-based Process Isolation
broader: IO Port Restriction
broader: Kernel-based Process Isolation
member-of: CCICatalog v2022-04-05
date published: 2013-07-02T00:00:00
contributor: DISA FSO
definition: The information system provides the capability to dynamically isolate/segregate organization-defined information system components from other components of the system.

CCI-002420
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Encrypted Tunnels
date published: 2013-07-02T00:00:00
contributor: DISA FSO
definition: The information system maintains the confidentiality and/or integrity of information during preparation for transmission.

CCI-002421
type: NamedIndividual
type: CCI Control
broader: Encrypted Tunnels
member-of: CCICatalog v2022-04-05
date published: 2013-07-02T00:00:00
contributor: DISA FSO
definition: The information system implements cryptographic mechanisms to prevent unauthorized disclosure of information and/or detect changes to information during transmission unless otherwise protected by organization-defined alternative physical safeguards.

CCI-002422
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Encrypted Tunnels
date published: 2013-07-02T00:00:00
contributor: DISA FSO
definition: The information system maintains the confidentiality and/or integrity of information during reception.

CCI-002423
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Encrypted Tunnels
date published: 2013-07-02T00:00:00
contributor: DISA FSO
definition: The information system implements cryptographic mechanisms to protect message externals (e.g., message headers and routing information) unless otherwise protected by organization-defined alternative physical safeguards.

CCI-002425
type: NamedIndividual
type: CCI Control
member-of: CCICatalog v2022-04-05
narrower: Encrypted Tunnels
date published: 2013-07-02T00:00:00
contributor: DISA FSO
definition: The information system implements cryptographic mechanisms to conceal or randomize communication patterns unless otherwise protected by organization-defined alternative physical safeguards.

CCI-002426
type: NamedIndividual
type: CCI Control
broader: Encrypted Tunnels
member-of: CCICatalog v2022-04-05
date published: 2013-07-02T00:00:00
contributor: DISA FSO
definition: The information system provides a trusted communications path that is logically isolated and distinguishable from other paths.