An autoregressive integrated moving average (ARIMA) model is a generalization of an autoregressive moving average (ARMA) model.
## References Wikipedia. (n.d.). Autoregressive integrated moving average. [Link](https://en.wikipedia.org/wiki/Autoregressive_integrated_moving_average)
Autoregressive Integrated Moving Average Model
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).
## References Wikipedia. (n.d.). Autoregressive-moving-average model. [Link](https://en.wikipedia.org/wiki/Autoregressive%E2%80%93moving-average_model)
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 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.
## References The Actor-Critic Reinforcement Learning Algorithm. Medium. [Link](https://medium.com/intro-to-artificial-intelligence/the-actor-critic-reinforcement-learning-algorithm-c8095a655c14).
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).
## References GeeksforGeeks. (n.d.). Adaptive Resonance Theory (ART). [Link](https://www.geeksforgeeks.org/adaptive-resonance-theory-art/)
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.
## 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, complete, average) to determine which produces the most cohesive clusters for the data at hand. ## Platforms, Tools, or Libraries - **scikit-learn**: - A versatile machine learning library in Python. - The `AgglomerativeClustering` class in scikit-learn provides this functionality. - **SciPy**: - A Python library used for scientific and technical computing. - The `scipy.cluster.hierarchy` module provides functions for hierarchical and agglomerative clustering, including the `linkage` and `dendrogram` functions. - **R**: - The `hclust` function in the stats package provides agglomerative clustering. - The `agnes` function in the `cluster` package offers a more extensive implementation. - **MATLAB**: - Offers the `linkage` function for hierarchical agglomerative clustering and `dendrogram` for visualization. - **Weka**: - A collection of machine learning algorithms for data mining tasks. - The `HierarchicalClusterer` class provides an implementation of agglomerative clustering. ## References 1. Jain, A. K., & Dubes, R. C. (1988). *Algorithms for clustering data*. Prentice-Hall, Inc. 2. Murtagh, F., & Legendre, P. (2014). Ward’s hierarchical agglomerative clustering method: which algorithms implement Ward’s criterion?. *Journal of Classification*, 31(3), 274-295. [Link](https://link.springer.com/article/10.1007/s00357-014-9161-z). 3. Scikit-learn. (30 Jun 2023). Scikit-learn Documentation: Agglomerative Clustering. [Link](https://scikit-learn.org/stable/modules/generated/sklearn.cluster.AgglomerativeClustering.html).
Alethic logic is a modal logic that addresses the modalities of necessity and possibility.
## References 1. Alethic logic. (2023, June 4). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Modal_logic#Alethic_logic)
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).
Answer set programming is a form of declarative programming based on the stable model (answer set) semantics of logic programming.
## 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)
Collects information on applications on an endpoint.
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.
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.
Association rule learning is a rule-based machine learning method for discovering interesting relations between variables in large databases.
## References Association rule learning. (n.d.). Wikipedia. [Link](https://en.wikipedia.org/wiki/Association_rule_learning)
Asymmetric Feature-based Transfer Learning
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.
## 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).
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.
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.
## 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.)
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.
## References Wikipedia. (n.d.). Autoregressive model. [Link](https://en.wikipedia.org/wiki/Autoregressive_model)
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.
## 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))
Bidirectional Encoder Representations from Transformers
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.
A probabilistic model that makes the most probable prediction for a new example.
## 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).
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).
## References Wikipedia. (n.d.). Bayes estimator. [Link](https://en.wikipedia.org/wiki/Bayes_estimator)
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.
## 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 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.
## References Wikipedia. (n.d.). Bayesian linear regression. [Link](https://en.wikipedia.org/wiki/Bayesian_linear_regression)
A supervised learning method that builds a Bayesian linear regression model using training data.
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.
## 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 (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)
## 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).
Boolean expression matching produces a Boolean truth value for a given boolean expression and assignment of values to variables in the expression.
## 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 is a sequential process where each subsequent model attempts to correct the errors of the previous model
## 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)
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.
## References Ensemble learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Ensemble_learning).
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.
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.
## References C4.5 algorithm. Wikipedia. [Link](https://en.wikipedia.org/wiki/C4.5_algorithm).
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.
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
Sensitive Cookie Without 'HttpOnly' Flag
Insufficient Visual Distinction of Homoglyphs Presented to User
Improper Restriction of Rendered UI Layers or Frames
Use of Web Link to Untrusted Target with window.opener Access
Struts: Incomplete validate() Method Definition
Processor Optimization Removal or Modification of Security-critical Code
Automated Recognition Mechanism with Inadequate Detection or Handling of Adversarial Input Perturbations
Struts: Form Bean Does Not Extend Validation Class
Static Member Data Element outside of a Singleton Class Element
Data Element Aggregating an Excessively Large Number of Non-Primitive Elements
Architecture with Number of Horizontal Layers Outside of Expected Range
Parent Class with a Virtual Destructor and a Child Class without a Virtual Destructor
Creation of Immutable Text Using String Concatenation
Invokable Control Element with Large Number of Outward Calls
Excessive Data Query Operations in a Large Data Table
Excessive Platform Resource Consumption within a Loop
Initialization with Hard-Coded Network Resource Configuration Data
Excessive Use of Hard-Coded Literals in Initialization
Invocation of a Control Element at an Unnecessarily Deep Horizontal Layer
Multiple Inheritance from Concrete Classes
Invokable Control Element with Variadic Parameters
Data Access Operations Outside of Expected Data Manager Component
Invokable Control Element in Multi-Thread Context with non-Final Static Storable or Member Element
Excessive Number of Inefficient Server-Side Data Accesses
Parent Class with References to Child Class
Creation of Class Instance within a Static Code Block
Invokable Control Element with Signature Containing an Excessive Number of Parameters
Runtime Resource Management Control Element in a Component Built to Run on Application Servers
Excessive Execution of Sequential Searches of Data Resource
Inconsistency Between Implementation and Documented Design
Serializable Data Element Containing non-Serializable Item Elements
Data Resource Access without Use of Connection Pooling
Non-SQL Invokable Control Element with Excessive Number of Data Resource Accesses
Unconditional Control Flow Transfer outside of Switch Block
Floating Point Comparison with Incorrect Operator
Parent Class without Virtual Destructor Method
Source Code File with Excessive Number of Lines of Code
Class Instance Self Destruction Control Element
Data Access from Outside Expected Data Manager Component
Invokable Control Element with Excessive File or Data Access Operations
Invokable Control Element with Excessive Volume of Commented-out Code
Class with Excessive Number of Child Classes
Class with Virtual Method without a Virtual Destructor
Synchronous Access of Remote Resource without Timeout
Large Data Table with Excessive Number of Indices
Method Containing Access of a Member Element from Another Class
Use of Object without Invoking Destructor Method
Use of Same Invokable Control Element in Multiple Architectural Layers
Excessive Index Range Scan for a Data Resource
Loop Condition Value Update within the Loop
Singleton Class Instance Creation without Proper Locking or Synchronization
Persistent Storable Data Element without Associated Comparison Control Element
Data Element containing Pointer Item without Proper Copy Control Element
Inconsistent Naming Conventions for Identifiers
ASP.NET Misconfiguration: Creating Debug Binary
Insufficient Isolation of System-Dependent Functions
Reliance on Runtime Component in Generated Code
Reliance on Machine-Dependent Data Representation
Use of Platform-Dependent Third Party Components
Use of Unmaintained Third Party Components
Insufficient Isolation of Symbolic Constant Definitions
Use of Same Variable for Multiple Purposes
Incomplete Documentation of Program Execution
Source Code Element without Standard Prologue
Callable with Insufficient Behavioral Summary
Insufficient Documentation of Error Handling Techniques
Excessive Use of Unconditional Branching
Declaration of Variable with Unnecessarily Wide Scope
Compilation with Insufficient Warnings or Errors
Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')
ASP.NET Misconfiguration: Improper Model Validation
DMA Device Enabled Too Early in Boot Phase
On-Chip Debug and Test Interface With Improper Access Control
System-on-Chip (SoC) Using Components without Unique, Immutable Identifiers
Power-On of Untrusted Execution Core Before Enabling Fabric Access Control
ASP.NET Misconfiguration: Missing Custom Error Page
Incorrect Register Defaults or Module Parameters
Insufficient Granularity of Address Regions Protected by Register Locks
Race Condition for Write-Once Attributes
Improper Restriction of Write-Once Bit Fields
Improper Prevention of Lock Bit Modification
Improper Lock Behavior After Power State Transition
Security-Sensitive Hardware Controls with Missing Lock Bit Protection
Hardware Internal or Debug Modes Allow Override of Locks
Incorrect Use of Autoboxing and Unboxing for Performance Critical Operations
Improper Neutralization of Formula Elements in a CSV File
Improper Zeroization of Hardware Register
Use of a Cryptographic Primitive with a Risky Implementation
Use of Predictable Algorithm in Random Number Generator
Inclusion of Undocumented Features or Chicken Bits
Sensitive Non-Volatile Information Not Protected During Debug
Internal Asset Exposed to Unsafe Debug Access Level or State
Improper Finite State Machines (FSMs) in Hardware Logic
Improper Write Handling in Limited-write Non-Volatile Memories
Improper Protection Against Voltage and Clock Glitches
Semiconductor Defects in Hardware Logic with Security-Sensitive Implications
Application-Level Admin Tool with Inconsistent View of Underlying Operating System
CPU Hardware Not Configured to Support Exclusivity of Write and Execute Operations
Comparison Logic is Vulnerable to Power Side-Channel Attacks
Improper Restriction of Software Interfaces to Hardware Features
Improper Access Control Applied to Mirrored or Aliased Memory Regions
Exposure of Sensitive System Information Due to Uncleared Debug Information
Improper Restriction of Security Token Assignment
Improper Handling of Overlap Between Protected Memory Ranges
Improper Handling of Single Event Upsets
Improper Access Control for Register Interface
Hardware Logic with Insecure De-Synchronization between Control and Data Channels
Unintended Reentrant Invocation of Non-reentrant Code Via Nested Calls
Improper Scrubbing of Sensitive Data from Decommissioned Device
Policy Privileges are not Assigned Consistently Between Control and Data Agents
Product Released in Non-Release Configuration
Uninitialized Value on Reset for Registers Holding Security Settings
Sensitive Information Uncleared Before Debug/Power State Transition
Improper Access Control for Volatile Memory Containing Boot Code
Sensitive Cookie with Improper SameSite Attribute
Hardware Child Block Incorrectly Connected to Parent System
Missing Protection Against Hardware Reverse Engineering Using Integrated Circuit (IC) Imaging Techniques
Cryptographic Operations are run Before Supporting Units are Ready
Access Control Check Implemented After Asset is Accessed
Sequence of Processor Instructions Leads to Unexpected Behavior
Assumed-Immutable Data is Stored in Writable Memory
Mutable Attestation or Measurement Reporting Data
Improper Validation of Specified Type of Input
Improper Validation of Consistency within Input
Improper Validation of Unsafe Equivalence in Input
Incorrect Decoding of Security Identifiers
Public Key Re-Use for Signing both Debug and Production Code
Incorrect Conversion of Security Identifiers
Missing Source Correlation of Multiple Independent Data
Debug Messages Revealing Unnecessary Information
Incorrect Chaining or Granularity of Debug Components
Unprotected Confidential Information on Device is Accessible by OSAT Vendors
Missing Protection Mechanism for Alternate Hardware Interface
ASP.NET Misconfiguration: Password in Configuration File
Improper Handling of Length Parameter Inconsistency
Non-Transparent Sharing of Microarchitectural Resources
Improperly Preserved Integrity of Hardware Configuration State During a Power Save/Restore Operation
Improper Translation of Security Attributes by Fabric Bridge
Missing Protection for Mirrored Regions in On-Chip Fabric Firewall
Hardware Allows Activation of Test or Debug Logic at Runtime
Missing Write Protection for Parametric Data Values
Improper Setting of Bus Controlling Capability in Fabric End-point
Fabric-Address Map Allows Programming of Unwarranted Overlaps of Protected and Unprotected Ranges
Improper Access Control in Fabric Bridge
Missing Support for Security Features in On-chip Fabrics or Buses
Improper Protection against Electromagnetic Fault Injection (EM-FI)
Improper Protection for Outbound Error Messages and Alert Signals
Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Use of Blocking Code in Single-threaded, Non-blocking Context
Improper Management of Sensitive Trace Data
Improperly Controlled Sequential Memory Allocation
Missing Immutable Root of Trust in Hardware
Security Version Number Mutable to Older Versions
Remanent Data Readable after Memory Erase
Improper Isolation of Shared Resources in Network On Chip (NoC)
Improper Handling of Faults that Lead to Instruction Skips
Inefficient Regular Expression Complexity
Unauthorized Error Injection Can Degrade Hardware Redundancy
Improper Neutralization of Special Elements Used in a Template Engine
Improper Protections Against Hardware Overheating
Insufficient Precision or Accuracy of a Real Number
Use of Externally-Controlled Format String
Information Exposure through Microarchitectural State after Transient Execution
Incorrect Calculation of Multi-Byte String Length
Improper Handling of Hardware Behavior in Exceptionally Cold Environments
Insecure Operation on Windows Junction / Mount Point
Incorrect Parsing of Numbers with Different Radices
Dependency on Vulnerable Third-Party Component
Compiler Removal of Code to Clear Buffers
Improper Neutralization of Parameter/Argument Delimiters
Improper Neutralization of Value Delimiters
Improper Neutralization of Record Delimiters
Improper Neutralization of Line Delimiters
Improper Neutralization of Section Delimiters
Improper Neutralization of Expression/Command Delimiters
Improper Neutralization of Input Leaders
Improper Neutralization of Quoting Syntax
External Control of System or Configuration Setting
Improper Neutralization of Escape, Meta, or Control Sequences
Improper Neutralization of Comment Delimiters
Improper Neutralization of Macro Symbols
Improper Neutralization of Substitution Characters
Improper Neutralization of Variable Name Delimiters
Improper Neutralization of Null Byte or NUL Character
Improper Handling of Missing Special Element
Improper Handling of Additional Special Element
Improper Handling of Inconsistent Special Elements
Improper Handling of URL Encoding (Hex Encoding)
Incorrect Behavior Order: Validate Before Canonicalize
Incorrect Behavior Order: Validate Before Filter
Exposure of Sensitive Information Through Data Queries
Observable Internal Behavioral Discrepancy
Observable Behavioral Discrepancy With Equivalent Products
Self-generated Error Message Containing Sensitive Information
Exposure of Sensitive Information Due to Incompatible Policies
Invocation of Process Using Visible Sensitive Information
Insertion of Sensitive Information Into Debugging Code
Storage of File With Sensitive Data Under FTP Root
Truncation of Security-relevant Information
Obscured Security-relevant Information by Alternate Name
Improper Handling of Undefined Parameters
Improper Handling of Incomplete Structural Elements
Improper Handling of Unexpected Data Type
Creation of chroot Jail Without Changing Working Directory
Improper Clearing of Heap Memory Before Release ('Heap Inspection')
J2EE Bad Practices: Direct Management of Connections
J2EE Bad Practices: Direct Use of Sockets
Incorrect Check of Function Return Value
Storing Passwords in a Recoverable Format
Improper Handling of Insufficient Privileges
Insecure Preserved Inherited Permissions
Incorrect Execution-Assigned Permissions
Improper Handling of Insufficient Permissions or Privileges
Reliance on IP Address for Authentication
Improper Following of a Certificate's Chain of Trust
Improper Validation of Certificate with Host Mismatch
Improper Validation of Certificate Expiration
Reflection Attack in an Authentication Protocol
Authentication Bypass by Assumed-Immutable Data
Authentication Bypass by Primary Weakness
Improper Restriction of Excessive Authentication Attempts
Use of Password System for Primary Authentication
Cleartext Storage of Sensitive Information in a Cookie
Cleartext Storage of Sensitive Information in Memory
Cleartext Storage of Sensitive Information in GUI
Cleartext Storage of Sensitive Information in Executable
Key Exchange without Entity Authentication
Generation of Predictable IV with CBC Mode
Improper Handling of Insufficient Entropy in TRNG
Same Seed in Pseudo-Random Number Generator (PRNG)
Predictable Seed in Pseudo-Random Number Generator (PRNG)
Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
Predictable Exact Value from Previous Values
Predictable Value Range from Previous Values
Improper Verification of Cryptographic Signature
Acceptance of Extraneous Untrusted Data With Trusted Data
Reliance on Reverse DNS Resolution for a Security-Critical Action
Improper Validation of Integrity Check Value
Product UI does not Warn User of Unsafe Actions
Improperly Implemented Security Check for Standard
Exposure of Private Personal Information to an Unauthorized Actor
Path Traversal: '/absolute/pathname/here'
Missing Check for Certificate Revocation after Initial Check
Passing Mutable Objects to an Untrusted Method
Returning a Mutable Object to an Untrusted Caller
Creation of Temporary File With Insecure Permissions
Creation of Temporary File in Directory with Insecure Permissions
Path Traversal: '\absolute\pathname\here'
J2EE Bad Practices: Use of System.exit()
J2EE Bad Practices: Direct Use of Threads
Symbolic Name not Mapping to Correct Object
Detection of Error Condition Without Action
Use of NullPointerException Catch to Detect NULL Pointer Dereference
Declaration of Catch for Generic Exception
Declaration of Throws for Generic Exception
Path Traversal: '\\UNC\share\name\' (Windows UNC Share)
Missing Release of Memory after Effective Lifetime
Exposure of File Descriptor to Unintended Control Sphere ('File Descriptor Leak')
Insufficient Control of Network Message Volume (Network Amplification)
Incorrect Behavior Order: Early Amplification
Improper Handling of Highly Compressed Data (Data Amplification)
Race Condition During Access to Alternate Channel
Unprotected Windows Messaging Channel ('Shatter')
Path Equivalence: 'filename....' (Multiple Trailing Dot)
Dangerous Signal Handler not Disabled During Sensitive Operations
Unrestricted Upload of File with Dangerous Type
Behavioral Change in New Version or Environment
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Unimplemented or Unsupported Feature in UI
Path Equivalence: 'file...name' (Multiple Internal Dot)
Insecure Default Variable Initialization
External Initialization of Trusted Variables or Data Stores
Path Equivalence: 'filename ' (Trailing Space)
Duplicate Key in Associative List (Alist)
Return of Pointer Value Outside of Expected Range
Use of Pointer Subtraction to Determine Size
Path Equivalence: ' filename' (Leading Space)
Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')
External Control of Assumed-Immutable Web Parameter
Missing Default Case in Multiple Condition Expression
Signal Handler Use of a Non-reentrant Function
Path Equivalence: 'file name' (Internal Whitespace)
Exposure of Data Element to Wrong Session
Path Equivalence: 'filename/' (Trailing Slash)
Public cloneable() Method Without Final ('Object Hijack')
Use of Inner Class Containing Sensitive Data
Download of Code Without Integrity Check
Private Data Structure Returned From A Public Method
Public Data Assigned to Private Array-Typed Field
Cloneable Class Containing Sensitive Information
Serializable Class Containing Sensitive Data
J2EE Misconfiguration: Data Transmission Without Encryption
Path Equivalence: '//multiple/leading/slash'
Replicating Malicious Code (Virus or Worm)
Path Equivalence: '/multiple//internal/slash'
Path Equivalence: '/multiple/trailing/slash//'
.NET Misconfiguration: Use of Impersonation
Use of Web Browser Cache Containing Sensitive Information
Cleartext Storage of Sensitive Information in an Environment Variable
Exposure of Version-Control Repository to an Unauthorized Control Sphere
Exposure of Core Dump File to an Unauthorized Control Sphere
Exposure of Access Control List Files to an Unauthorized Control Sphere
Path Equivalence: '\multiple\\internal\backslash'
Exposure of Backup File to an Unauthorized Control Sphere
Inclusion of Sensitive Information in Test Code
Insertion of Sensitive Information into Log File
Exposure of Information Through Shell Error Message
Servlet Runtime Error Message Containing Sensitive Information
Java Runtime Error Message Containing Sensitive Information
Use of Persistent Cookies Containing Sensitive Information
Path Equivalence: 'filedir\' (Trailing Backslash)
Inclusion of Sensitive Information in an Include File
Use of Singleton Pattern Without Synchronization in a Multithreaded Context
Missing Standardized Error Handling Mechanism
Use of Hard-coded, Security-relevant Constants
Exposure of Information Through Directory Listing
Path Equivalence: '/./' (Single Dot Directory)
Server-generated Error Message Containing Sensitive Information
Incorrect Behavior Order: Authorization Before Parsing and Canonicalization
Command Shell in Externally Accessible Directory
ASP.NET Misconfiguration: Not Using Input Validation Framework
J2EE Misconfiguration: Plaintext Password in Configuration File
ASP.NET Misconfiguration: Use of Identity Impersonation
Use of getlogin() in Multithreaded Application
Use of umask() with chmod-style Argument
Authorization Bypass Through User-Controlled SQL Primary Key
Unsynchronized Access to Shared Data in a Multithreaded Context
finalize() Method Without super.finalize()
Path Equivalence: 'fakedir/../realdir/filename'
EJB Bad Practices: Use of Synchronization Primitives
J2EE Bad Practices: Non-serializable Object Stored in Session
Object Model Violation: Just One of Equals and Hashcode Defined
Array Declared Public, Final, and Static
Assignment of a Fixed Address to a Pointer
Attempt to Access Child of a Non-structure Pointer
Sensitive Data Storage in Improperly Locked Memory
Authentication Bypass: OpenSSL CTX Object Modified after SSL Objects are Created
J2EE Framework: Saving Unserializable Objects to Disk
Use of Wrong Operator in String Comparison
Use of GET Request Method With Sensitive Query Strings
Missing Validation of OpenSSL Certificate
J2EE Misconfiguration: Insufficient Session-ID Length
URL Redirection to Untrusted Site ('Open Redirect')
Public Static Final Field References Mutable Object
Struts: Non-private Field in ActionForm Class
Improper Restriction of XML External Entity Reference
Improper Authorization of Index Containing Sensitive Information
Sensitive Cookie in HTTPS Session Without 'Secure' Attribute
Inclusion of Sensitive Information in Source Code Comments
Incomplete Identification of Uploaded File Variables (PHP)
Dangling Database Cursor ('Cursor Injection')
Improper Validation of Function Hook Arguments
Unsafe ActiveX Control Marked Safe For Scripting
Null Byte Interaction Error (Poison Null Byte)
Unnecessary Complexity in Protection Mechanism (Not Using 'Economy of Mechanism')
Weak Password Recovery Mechanism for Forgotten Password
Improper Restriction of Names for Files and Other Resources
Improper Neutralization of Data within XPath Expressions ('XPath Injection')
Improper Neutralization of HTTP Headers for Scripting Syntax
Overly Restrictive Account Lockout Mechanism
Reliance on File Name or Extension of Externally-Supplied File
Use of Non-Canonical URL Paths for Authorization Decisions
Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking
Trusting HTTP Permission Methods on the Server Side
Exposure of WSDL File Containing Sensitive Information
Improper Neutralization of Data within XQuery Expressions ('XQuery Injection')
Insufficient Psychological Acceptability
Improper Handling of Windows Device Names
Function Call With Incorrect Order of Arguments
Function Call With Incorrect Number of Arguments
Function Call With Incorrect Argument Type
Function Call With Incorrect Variable or Reference as Argument
Permission Race Condition During Resource Copy
Improper Handling of Windows ::DATA Alternate Data Stream
Unchecked Return Value to NULL Pointer Dereference
Incomplete Denylist to Cross-Site Scripting
J2EE Misconfiguration: Missing Custom Error Page
Improper Handling of Apple HFS+ Alternate Data Stream Path
Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')
Improper Neutralization of Equivalent Special Elements
Use of a One-Way Hash with a Predictable Salt
Access to Critical Private Variable via Public Method
Missing Reference to Active File Descriptor or Handle
Allocation of File Descriptors or Handles Without Limits or Throttling
Missing Release of File Descriptor or Handle after Effective Lifetime
Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Improper Address Validation in IOCTL with METHOD_NEITHER I/O Control Code
Exposed IOCTL with Insufficient Access Control
Reliance on Cookies without Validation and Integrity Checking in a Security Decision
Use of Path Manipulation Function without Maximum-sized Buffer
Memory Allocation with Excessive Size Value
Only Filtering One Instance of a Special Element
Incomplete Filtering of Multiple Instances of Special Elements
Only Filtering Special Elements Relative to a Marker
Only Filtering Special Elements at an Absolute Position
J2EE Misconfiguration: Entity Bean Declared Remote
Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
Buffer Access Using Size of Source Buffer
Improper Neutralization of Script in an Error Message Web Page
Improper Neutralization of Script in Attributes of IMG Tags in a Web Page
Premature Release of Resource During Expected Lifetime
Improper Control of Document Type Definition
Inclusion of Web Functionality from an Untrusted Source
Signal Handler Function Associated with Multiple Signals
Loop with Unreachable Exit Condition ('Infinite Loop')
Use of Password Hash Instead of Password for Authentication
Improper Enforcement of a Single, Unique Action
Inappropriate Encoding for Output Context
Numeric Range Comparison Without Minimum Check
Improper Neutralization of Encoded URI Schemes in a Web Page
Improper Enforcement of Behavioral Workflow
Access of Resource Using Incompatible Type ('Type Confusion')
Improper Neutralization of Invalid Characters in Identifiers in Web Pages
Improper Neutralization of Alternate XSS Syntax
Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
J2EE Misconfiguration: Weak Access Permissions for EJB Methods
Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection')
Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')
Improper Restriction of Power Consumption
Storage of Sensitive Data in a Mechanism without Access Control
Improper Enforcement of Message Integrity During Transmission in a Communication Channel
Improper Verification of Intent by Broadcast Receiver
Improper Export of Android Application Components
Use of Implicit Intent for Sensitive Communication
Improper Authorization in Handler for Custom URL Scheme
Incorrectly Specified Destination in a Communication Channel
Permissive Cross-domain Policy with Untrusted Domains
Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')
Improper Neutralization of Server-Side Includes (SSI) Within a Web Page
Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion')
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.
## References Wikipedia. (n.d.). Canopy clustering algorithm. [Link](https://en.wikipedia.org/wiki/Canopy_clustering_algorithm)
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.
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).
Senses data from cloud service platforms. Including data from cloud service authentications, authorizations, and other activities.
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.
A commonly applied series of techniques which induce a greater effect than each individual technique. The techniques are applied in a strict sequence.
A compute server is a system specifically designed to undertake large amounts of computation, usually but not necessarily in a client/server environment.
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.
Outputs characters to a computer console.
A software build tool that creates a container (e.g., Docker container) for deployment.
A running instance of a d3f:ContainerImage
A software layer between d3f:ContainerProcess and d3f:Kernel which often mediates the invocation of d3f:SystemCall
Copies a memory block from one location to another.
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.
## References Wikipedia. (n.d.). Cramér's V. [Link](https://en.wikipedia.org/wiki/Cram%C3%A9r%27s_V)
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.
## References Esri. (n.d.). How CycleGAN Works. [Link](https://developers.arcgis.com/python/guide/how-cyclegan-works/)
A density-based clustering algorithm that works on the assumption that clusters are dense regions in space separated by regions of lower density.
## 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.)
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.
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.
## References OpenReview. (n.d.). Unsupervised Clustering using Pseudo Ensemble Models. [Link](https://openreview.net/pdf?id=B1eT9VMgOX)
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.
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.
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.
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.
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.
Datalog is a declarative logic programming language that is a syntactically a subset of Prolog.
## 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)
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
## References scikit-learn. (n.d.). Decision Trees. [Link](https://scikit-learn.org/stable/modules/tree.html#tree)
Deep Convolutional GAN (DCGAN) uses convolutional and convolutional-transpose layers in the generator and discriminator, respectively.
## 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/)
Uses a deep convolutional neural network, with layers of tiled convolutional filters to mimic the effects of receptive fields.
## References Q-learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Q-learning#Deep_Q-learning).
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.
## References Intro to Active Learning. inovex Blog. [Link](https://www.inovex.de/de/blog/intro-to-active-learning/).
Deontic logic addresses the modality of obligations and norms; i.e., the modality of morality.
## References 1. Deontic logic. (2023, June 4). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Modal_logic#Deontic_logic)
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.
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.
Discriminant analysis attempts to establish whether a set of variables can be used to distinguish between two or more groups of cases.
## References Wikipedia. (n.d.). Multivariate statistics. [Link](https://en.wikipedia.org/wiki/Multivariate_statistics)
A divisive clustering approach is a hierarchical, top-down approach to clustering a dataset.
A Dyna-Q agent combines acting, learning, and planning.
## References CompNeuro Neuromatch Academy Tutorials. [Link](https://compneuro.neuromatch.io/tutorials/W3D4_ReinforcementLearning/student/W3D4_Tutorial4.html)
Dynamic program analysis is the analysis of computer software that is performed by executing programs on a real or virtual processor.
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.
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.
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.
Epistemic logic addresses modalities of knowledge; i.e., the certainty of sentences.
## References 1. Epistemic logic. (2023, June 4). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Modal_logic#Epistemic_logic)
Exact matching for numeric types is just the simple test for mathematical equivalence of the values being matched.
## References 1. Equality (mathematics). (2023, May 31). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Equality_(mathematics)]
An exception handler is a code segment that processes an exception.
An unsupervised clustering algorithm and extends to NLP applications like Latent Dirichlet Allocation, the Baum-Welch algorithm for Hidden Markov Models, and medical imaging.
## 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 (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
Supervised learning establishes a relationship between the known input and output variables to conduct a predictive analysis.
nal Consiterations ## References Intro to Active Learning. inovex Blog. [Link](https://www.inovex.de/de/blog/intro-to-active-learning/).
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.
Has an input of a file path, and opens a file handle for reading or writing.
A file sharing service (or file share service) provides the ability to share data across a network.
Collects files and file metadata on an endpoint.
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.
Collects information on firmware installed on an Endpoint.
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.
## 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 solution. ### Validation Approach - Domain SMEs should be identified to review the analytics results and compare them to expected results for a given input. - Where possible, an outside team of SMEs should inspect the formal logic specification of a system against its stated requirements and suitability to address its domain problem sets. - Defining a set of competency questions and the expected results provides one means of validation. ## References 1. First-order logic. (2023, May 26). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/First-order_logic) 2. Shapiro, S. and Kissel, T. Classical Logic. (2022). Stanford Encyclopedia of Philosophy. [Link](https://plato.stanford.edu/entries/logic-classical/) 3. A.I. For Anyone. First-order Logic (n.d.). [Link](https://www.aiforanyone.org/glossary/first-order-logic) 4. Smith, P. An Introduction to Formal Logic. (2020). [Link](https://doi.org/10.1017/9781108328999) 5. Gruninger, M. and Fox, M. (1995). Methodology for the Design and Evaluation of Ontologies. [Link](https://www.researchgate.net/publication/2288533_Methodology_for_the_Design_and_Evaluation_of_Ontologies) 6. Keet, C., Suarez-Figurosa, M., and Poveda-Villalon, M. (2014). Pitfalls in Ontologies and TIPS to Prevent Them. [Link](https://dl.acm.org/doi/10.4018/ijswis.2014040102) 7. Bjorner, N. et al. The inner magic behind the Z3 theorem prover. (2019) [Link](https://www.microsoft.com/en-us/research/blog/the-inner-magic-behind-the-z3-theorem-prover/)
The very first routine run in order to load the operating system.
Flash memory is an electronic non-volatile computer memory storage medium that can be electrically erased and reprogrammed.
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.
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.
## 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)
Generative pre-trained transformers (GPT) are a type of large language model (LLM) and a prominent framework for generative artificial intelligence.
## References Generative pre-trained transformer. (n.d.). In Wikipedia. [Link](https://en.wikipedia.org/wiki/Generative_pre-trained_transformer)
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
## References Wikipedia. (2021, September 20). Gated Recurrent Unit. [Link](https://en.wikipedia.org/wiki/Gated_recurrent_unit)
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.
## 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]
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.
## Reference 1. Google. (28 Sep 2023). Gradient Boosted Decision Trees. [Link](https://developers.google.com/machine-learning/decision-forests/intro-to-gbdt).
Graph-based Semi-Supervised Learning (GSSL) methods aim to classify unlabeled data by learning the graph structure and labeled data jointly.
## 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).
Firmware that is installed on computer graphics card.
A class of neural networks that specializes in processing data that has a grid-like topology, such as an image.
## References Talukdar, P. (2020, June 10). Convolutional Neural Networks Explained. Towards Data Science. [Link](https://towardsdatascience.com/convolutional-neural-networks-explained-9cc5188c4939)
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.
## References TechVidvan. (n.d.). Clustering in Machine Learning Tutorial. [Link](https://techvidvan.com/tutorials/clustering-in-machine-learning/)
Firmware that is installed on a hard disk device.
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
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.
## 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
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.
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.
## References 1. Higher-order logic. (2023, May 13). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Higher-order_logic)
Collects the configuration data on an endpoint.
A collection of Hosts used to allow operations such as access control to be applied to the entire group.
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.
Firmware that is installed on an HCI device such as a mouse or keyboard.
This method creates an asymmetric mapping from the target to the source and takes into account bias issues of cross-domain correspondences.
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.
## 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).
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.
Loads an external software library to enable the invocations of its methods.
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.
## 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).
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.
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.
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 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.
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.
Interval estimation is the use of sample data to estimate an interval of possible values of a parameter of interest.
## References Wikipedia. (n.d.). Interval estimation. [Link](https://en.wikipedia.org/wiki/Interval_estimation)
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 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.
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.
Intrusion Detection and Prevention System
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.
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.
## 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**: - **Silhouette Score**: The silhouette score refers to a scoring method that helps validate the consistency between clusters of data. The evaluation technique also produces a concise graphical representation of how well each object appear to have been classified. It is suited to K-centric Clustering in that it also works for different metric spaces. - **Distance Metric**: The distance measure must be a true metric (see [2]). Differences in the metric chosen may (e.g., Euclidean,a Manhattan) affect results significantly. - **Sensitivity**: Greedy implementations may be sensitive to outliers. ## Platforms, Tools, or Libraries N/A. _Note that this algorithm is relatively simple and so it is usually implemented from scratch by those incorporating this algorithm into a system._ ## References 1. Gonzalez, T.F. (1985). Clustering to Minimize the Maximum Intercluster Distance. Theor. Comput. Sci., 38, 293-306. [Link](https://www.sciencedirect.com/science/article/pii/0304397585902245?via%3Dihub). 1. Weisstein, Eric W. (n.d.). "Metric." From MathWorld--A Wolfram Web Resource. [Link](https://mathworld.wolfram.com/Metric.html). 1. Wikipedia. (8 Aug 2023). Metric k-center [Link](https://en.wikipedia.org/wiki/Metric_k-center). 1. Wikipedia. (14 Aug 2023). Vertex k-center problem. [Link](https://en.wikipedia.org/wiki/Vertex_k-center_problem). 1. Wikipedia. (n.d.). Rand Index. [Link](https://en.wikipedia.org/wiki/Rand_index). 1. Wikipedia. (n.d.). Adjusted Mutual Information. [Link](https://en.wikipedia.org/wiki/Adjusted_mutual_information). 1. Wikipedia. (1 Aug 2023). Silhouette (clustering). [Link](https://en.wikipedia.org/wiki/Silhouette_(clustering)).
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
## 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).
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.
## **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 an easy implementation and can adjust will to new training data. ## Key Test Considerations - **Supervised Learning:** - **Cross Validation:** As cross validation methods like k-fold, leave-one-out, and stratified cross validation can help validate model performance. However, nuances like pessimism bias in k-fold cross validation or high variability in leave-one-out cross validation may need consideration. - **Classification:** - **ROC Curve:** A standard technique used to summarize classifier performance over a range of tradeoffs between true and false positives is the Receiver Operating Characteristic (ROC) curve. - **Data Imbalance:** Imbalanced data sets where one class significantly outnumbers others, under sampling techniques like SMOTE may be beneficial in sampling minority classes. - **K-Nearest Neighbor** - **Choice of K:** The number of neighbors, K, affects the decision boundary. A smaller K can lead to a noisy decision boundary, while a large K can smooth it out, but may also blur class distinctions. - **K-d Tree:** Exact searching on large datasets can be computationally costly and inefficient. Implementing approximate nearest neighbor algorithms like the K-d tree algorithm. - **Dimensionality:** KNN does not perform well while using high-dimensional data and can be sensitive to irrelevant features which can lead to overfitting. - **Distance Metric:** Choosing the appropriate distance metric (Euclidean, Manhattan, MinKowski, Hamming etc.) is essential, based on the nature of the data. ## **References** 1. IBM. K-Nearest Neighbors Algorithm. [Link](https://www.ibm.com/topics/knn?mhsrc=ibmsearch_a&mhq=k-nearest%20neighbors%20). 2. Muja, M., & Lowe, D. G. (2014). Scalable nearest neighbor algorithms for high dimensional data. IEEE Transactions on Pattern Analysis and Machine Intelligence. [Link]( https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=6809191). 3. Chawla, N. V., Bowyer, K. W., Hall, L. O., & Kegelmeyer, W. P. (2002). SMOTE: synthetic minority over-sampling technique. Journal of artificial intelligence research, 16, 321-357. [Link]( https://www.jair.org/index.php/jair/article/view/10302/24590). 4. Kohavi, R. (1995). A study of cross-validation and bootstrap for accuracy estimation and model selection. Proceedings of the 14th international joint conference on Artificial intelligence . [Link]( https://www.ijcai.org/Proceedings/95-2/Papers/016.pdf).
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.
## 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 $\\tau$ 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." ;
## 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]""",
A Kerberos ticket-granting service (TGS) ticket is given in response to requesting a Kerberos TGS request.
Monitors system calls (operating system api functions).
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.
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
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.
## 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)
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
## 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 is a form of logic programming that uses linear logic, that is, it emphasizes the use of formulas as resources.
## 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)
Statistical regression method used for predictive analysis by modeling the linear relationship between independent and dependent variables.
## 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.analyticsvidhya.com/blog/2021/06/linear-regression-in-machine-learning/. 1. 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. 1. Ng, Ritchie. “Evaluating a Linear Regression Model.” Ritchieng.github.io, 8 Jan. 2023, https://www.ritchieng.com/machine-learning-evaluate-linear-regression-model/. 1. 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.
A supervised learning method that builds a linear regression model using training data.
## 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.
Creates a child process and provides more precise control over the data shared between the parent and child processes
Creates a child process and provides more precise control over the data shared between the parent and child processes. Newer system call.
A flag parameter to the Clone3 syscall. If set, the child is placed in the same thread group as the calling process.
A flag parameter to the Clone syscall. If set, the child is placed in the same thread group as the calling process.
Equivalent to calling Linux Open with flags equal to O_CREAT|O_WRONLY|O_TRUNC.
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.
Execute program relative to a directory file descriptor. Behavior is similar to Linux Execve.
Creates a child process with unique PID but retains parent PID as Parent Process Identifier (PPID)
Linux Open Argument O_RDONLY, O_WRONLY, O_RDWR
Create a regular file. Extension of Linux Openat.
Linux OpenAt2 Argument O_RDONLY, O_WRONLY, O_RDWR
Create a regular file. Same functionality as Linux Open but slight differences in parameter.
Linux OpenAt Argument O_RDONLY, O_WRONLY, O_RDWR
Same functionality as Linux Open but slight differences in parameter.
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.
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.
Attach to the process specified in pid, making it a tracee of the calling process.
Copy the tracee's general-purpose or floating-point registers, respectively, to the address data in the tracer.
Read a word at the address addr in the tracee's memory, returning the word as the result of the ptrace() call.
Copy the word data to the address addr in the tracee's memory.
Modify the tracee's general-purpose or floating-point registers, respectively, from the address data in the tracer.
Restart the stopped tracee as for PTRACE_CONT, but first detach from it.
Indicates that the process is to be traced by its parent.
Change the name or location of a file. Different parameter handling than Linux Rename.
Change the name or location of a file. Additional flags argument.
Delete a name and possibly the file it refers to.
Delete a name and possibly the file it refers to. Different parameter handling than Linux Unlink
Create child process that temp suspends parent process until it terminates
A local authentication service running on a host can authenticate a user logged into just that local host computer.
A local authorization service running on a host can authorize a user logged into just that local host computer.
Logistic regression is estimating the parameters of a logistic model.
## References Wikipedia. (n.d.). Logistic regression. [Link](https://en.wikipedia.org/wiki/Logistic_regression)
A supervised learning method that builds a logistic regression model using training data.
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
## References Wikipedia. (2021, September 29). Long short-term memory. [Link](https://en.wikipedia.org/wiki/Long_short-term_memory)
A future release of D3FEND will define a taxonomy of Source Code Hardening Techniques.
M1015 scope is broad, touches on an wide variety of techniques in D3FEND.
Future D3FEND releases will model the scanning and inventory domains.
Modeling user training is outside the scope of D3FEND.
Establishing and running a Threat Intelligence Program is outside the scope of D3FEND.
D3FEND models this as an infrastructure dependency to support D3-NTA.
M1021 scope is broad, touches on an wide variety of techniques in d3fend.
IT disaster recovery plans are outside the current scope of D3FEND.
D3-AZET may be related (is potentially related though not called out in ATT&CK definition.)
D3-SCF is one possible way to filter library loading.
M1047 scope is broad, touches on an wide variety of techniques in d3fend.
"Sandboxing" is often used to describe a detection environment which includes some forms of analysis (see D3-DA.)" Many forms of isolation (e.g., quarantining) are more static in nature and simply limit software's access to system resources.
Comprehensive IT disaster recovery plans are outside the current scope of D3FEND.
Maximum-margin classifiers attempt to maximize the distance between the given data points and the decision boundary
## 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.)
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.
Reserves memory for a running process to use.
Releases previously reserved memory associated with a process.
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.
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.
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,
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
## References MBPO Agents. MathWorks. [Link](https://www.mathworks.com/help/reinforcement-learning/ug/mbpo-agents.html).
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.
## References Policy and Value Iteration. Towards Data Science. [Link](https://towardsdatascience.com/policy-and-value-iteration-78501afb41d2).
the act of observing something (and sometimes keeping a record of it)
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.
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.
## Refrences Wikipedia. (n.d.). Moving average model. [Link](https://en.wikipedia.org/wiki/Moving_average_model)
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.
## References Multilayer perceptron. Wikipedia. [Link](https://en.wikipedia.org/wiki/Multilayer_perceptron).
Digital video files which often contain audio.
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.
## 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)
A supervised learning method that builds a multiple regression model using training data.
An NTFS hard link points to another file, and files share the same MFT entry (inode), in the same filesystem.
NTFS junction points are are similar to NTFS symlinks but are defined only for directories. Only accepts local absolute paths.
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.
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.
## References Naive Bayes. IBM. [Link](https://www.ibm.com/topics/naive-bayes?mhsrc=ibmsearch_a&mhq=naive%20bayes).
Firmware that is installed on a network card (network interface controller).
A directory resource made available from one host to other hosts on a computer network.
Monitors network traffic and produces summaries of data flows traversing the network.
A network link is a link within the network layer, which is responsible for packet forwarding including routing through intermediate routers.
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.)
Monitors and parses network protocols to extract values from various network protocol layers.
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.
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.
A non-parametric test relies is used when the underlying distribution of data is non-symmetric (non-normal distribution).
## 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-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.
## References 1. Non-monotonic logic. (2023, June 1). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Non-monotonic_logic)
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.
## References Wikipedia. (n.d.). Nonlinear regression. [Link](https://en.wikipedia.org/wiki/Nonlinear_regression)
A supervised learning method that builds a non-linear regression model using training data.
The Web Ontology Language (OWL) is a family of knowledge representation languages for authoring ontologies.
## 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)
A software packaging tool oriented on building a software package for a particular operating system (e.g. rpmbuild.)
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.
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.
An orchestration server provides orchestration services that automate the configuration, coordination, and management of computer systems and software.
A d3f:Server which receives commands from a d3f:OrchestrationController to execute workloads.
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.
A POSIX-compliant symbolic link. These are often fast symbolic links, but need not be.
A log of all the network packet data captured from a network by a network sensor (i.e., packet analyzer),
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.
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.
A parametric test relies upon the assumption that the data you want to test is (or approximately is) normally distributed.
## 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)
In computing, a parent process is a process that has created one or more child processes.
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.
## References Wolfram MathWorld. (n.d.). Correlation Coefficient. [Link](https://mathworld.wolfram.com/CorrelationCoefficient.html)
Firmware that is installed on peripheral hub device such as a USB or Firewire hub.
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.
## 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).
The phi coefficient (or mean square contingency coefficient is a measure of association for two binary variables.
## References \Wikipedia. (n.d.). Phi coefficient. [Link](https://en.wikipedia.org/wiki/Phi_coefficient)
Matthews Correlation Coefficient (in machine learning)
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.
## References Esri. (n.d.). How Pix2Pix Works. [Link](https://developers.arcgis.com/python/guide/how-pix2pix-works/)
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.
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.
## References Wikipedia. (n.d.). Point-biserial correlation coefficient. [Link](https://en.wikipedia.org/wiki/Point-biserial_correlation_coefficient)
A point estimation is a single value that estimates the parameter. Point estimates are single values calculated from the sample
## References Pennsylvania State University. (n.d.). Statistical Inference and Estimation. [Link](https://online.stat.psu.edu/stat504/lesson/statistical-inference-and-estimation)
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.
Principal Component Analysis (PCA) is a statistic-based method of identifying patterns in a large dataset while increasing interpretability and preserving information.
## References Wikipedia. (n.d.). Principal component analysis. [Link](https://en.wikipedia.org/wiki/Principal_component_analysis)
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.
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 extends traditional logic truth tables with probabilistic expressions.
## References 1. Probabilistic logic. (2023, June 5). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Probabilistic_logic)
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.
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.
## References Machine Learning Mastery. (n.d.). Introduction to Progressive Growing Generative Adversarial Networks. [Link](https://machinelearningmastery.com/introduction-to-progressive-growing-generative-adversarial-networks/)
Projected clustering is a dimension reduction subspace clustering method.
## References GeeksforGeeks. (n.d.). Projected Clustering in Data Analytics. [Link](https://www.geeksforgeeks.org/projected-clustering-in-data-analytics/)
Prolog has its roots in first-order logic, a formal logic, and unlike many other programming languages.
## 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)
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.
## 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)
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.
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.
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.
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.
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 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.
## References Random forest. Wikipedia. [Link](https://en.wikipedia.org/wiki/Random_forest).
The dataset is repeatedly sampled with a random split of the data into train and test sets.
## 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/).
Numeric Range Matching determines if a value lies with an interval of values (i.e., within the range of values.)
Reference - Apparatus for to provide content to and query a reverse domain name system server - Barrracuda Networks
An apparatus is disclosed for to provide content to and query a reverse domain name system (DNS) server without depending on the kindness of domain name system registrars, registrants. DNS replies are observed by firewalls or filters, analyzed, and transmitted to a reverse domain name system server. An embodiment of the present invention can be within a DNS server or SMTP server.
This patent includes the description of a method of blocking email traffic from untrusted domains by analyzing the TCP/IP source IP addresses and blocking traffic for IPs whose reverse lookup response FQDN matches a denylist.
Apparatus for to provide content to and query a reverse domain name system server
Reference - Biometric Challenge-Response Authentication - Accenture
Secret biometric responses to authentication challenges for MFA. Methods, systems, and apparatus, including computer programs encoded on computer storage media, for authenticating users based on a sequence of biometric authentication challenges. In one aspect, a process includes receiving a first image of the face of the user and processing the first image according to a first authentication process to determine whether the face of the user shown in the first image matches the face of an authorized user. A second authentication process including a sequence of biometric authentication challenges is identified. The sequence includes at least one facial expression challenge. The user is authenticated in response to determining that the first authentication process is satisfied based on the face of the user shown in the first image matching the face of the authorized user and the second authentication process is satisfied based on the user providing a valid biometric response to each biometric authentication challenge.
Biometric Challenge-Response Authentication
Reference - CAR-2020-11-010: CMSTP - MITRE
CMSTP.exe is the Microsoft Connection Manager Profile Installer, which can be leveraged to setup listeners that will receive and install malware from remote sources in trusted fashion. When CMSTP.exe is seen in combination with an external connection, it is a good indication of this TTP.
Reference - Embedding contexts for on-line threats into response policy zones - Verisign Inc
Hierarchical threat intelligence embedded in subdomain CNAMEs of a DNS denylist. In one embodiment, a response policy zone (RPZ) application generates an RPZ that includes contexts for the on-line threats that are associated with domain names. For a domain name that is associated with an on-line threat, the RPZ application determines a threat specification that describes a characteristic of the on-line threat. The RPZ application then generates an alias based on the domain name and the threat specification. Subsequently, the RPZ application generates a domain name system (DNS) resource record that maps the domain name to the alias, includes the resource record in the RPZ, and transmits the RPZ to a DNS name server that implements the RPZ. Upon receiving a DNS query associated with the domain name, the DNS name server generates a DNS response based on the alias. Because the domain name and the threat specification is reflected in the alias, the DNS response automatically provides a relevant context.
Embedding contexts for on-line threats into response policy zones
Reference - FWTK Documentation - fwtk.org
In case you don't already know, FWTK stands for the FireW all Tool Kit. It is used as a base to create a secure firewall system. If you need good documentation, please read the source code. If you are not familiar with C or do not feel comfortable with performing the configuration and security verification yourself, then I would suggest that you purchase a commercial firewall from a vendor (such as TIS, Checkpoint, Raptor, etc.). A machine needs other tools to secure it, including, but hardly limited to, tools to check files (tripwire), audit tools (tiger/cops), secure access methods (kerberos/ssh), something to watch logs and machine states (swatch/watcher some to mind) and filtering and routing tools such as screend/ipfilterd/ipacl. Again, I would recommend that you do not proceed to build a production FWTK firewall unless you are familiar with UNIX security.
Reference - Identification of visual international domain name collisions - Verisign Inc
Fuzzy OCR to detect domain name homoglyph attacks. Various embodiments of the invention disclosed herein provide techniques for detecting a homograph attack. An IDN collision detection server retrieves a first domain name that includes a punycode element. The IDN collision detection server converts the first domain into a second domain name that includes a Unicode character corresponding to the punycode element. The IDN collision detection server converts the second domain name into an image. The IDN collision detection server performs one or more optical character recognition operations on the image to generate a textual string associated with the image. The IDN collision detection server determines that the textual string matches at least a portion of a third domain name.
Identification of visual international domain name collisions
Reference - Intrusion and misuse deterrence system employing a virtual network
Intrusion and misuse deterrence system employing a virtual network
Reference - Libre NMS - Oxidized Extension
Integrating LibreNMS with Oxidized brings the following benefits: * Config viewing: Current, History, and Diffs all under the Configs tab of each device * Automatic addition of devices to Oxidized: Including filtering and grouping to ease credential management * Configuration searching
Reference - Reverse DNS Blocking - Barracuda Networks
Inbound corporate traffic SMTP traffic on port 25 can be routed through Barracuda Email Security Gateway before reaching the corporate mail server, acting as a traffic filter based on reverse DNS lookups and a denylist for blocking domains.
Reference - Securing Web Transactions TLS Server Certificate Management - Appendix A Passive Inspection
The example implementation demonstrates the ability to perform passive inspection of encrypted TLS connections. The question of whether or not to perform such an inspection is complex. There are important tradeoffs between traffic security and traffic visibility that each organization should consider. Some organizations prefer to decrypt internal TLS traffic, so it can be inspected to detect attacks that may be hiding within encrypted connections. Such inspection can detect intrusion, malware, and fraud, and can conduct troubleshooting, forensics, and performance monitoring. For these organizations, TLS inspection may serve as both a standard practice and a critical component of their threat detection and service assurance strategies.
Securing Web Transactions TLS Server Certificate Management - Appendix A Passive Inspection
Reference - System and method for managed security assessment and mitigation
In an embodiment of the invention, a system for assessing vulnerabilities includes: a security management system; a network device in a system under test (SUT), wherein the network device is privy to traffic in the SUT; and wherein the SMS is privy to traffic that is known by the network device and/or to one or more traffic observations that is known by the network device.
System and method for managed security assessment and mitigation
Reference - System and methods thereof for detection of persistent threats in a computerized environment background - Palo Alto Networks IncCyber Secdo Ltd
A system is used for detection of advanced persistent and non-persistent threats in a computerized environment. The system is connected to a plurality of user devices coupled to an enterprise's network. The system receives via an interface an electronic notification of at least one event in the operating system of the computer. The system then analyzes the at least one event. The system then generates a causality chain for the at least one event respective of the analysis. The causality chain comprises all the threads that attributed to the at least one event in a chronological order. The system then identifies a main thread that started the causality chain that led to the at least one event. Then, the system determines whether the main thread is associated with malicious software. Upon determination that the main thread is associated with malicious software, the causality chain is marked as infected.
The patent describes detecting malicious events on a host. For each new event (e.x. new file request received from a user device, a change in an existing file in a container) a causality chain is developed for all threads associated with the event. The causality chain identifies the thread that started the process of the event (main thread). If a thread in the causality chain has no parent, i.e. no main thread associated with it, the process is identified as malicious.
System and methods thereof for detection of persistent threats in a computerized environment background
Reference - Techniques for impeding and detecting network threats - Verisign Inc
Infinite DNS decoy trap resource to catch threats scanning for network resources to attack. In various embodiments, a name server transmits a canonical name as resolution to another canonical name. In operation, when a resource name is requested for resolution, a determination is made that the resource name corresponds to a trap resource name. A first canonical name is transmitted as resolution to the trap resource name. The first canonical name is requested for resolution, and a second canonical name is transmitted as resolution. By providing trap canonical names as resolutions to trap canonical names, unauthorized software making the resolution requests is kept occupied with requesting resolution of canonical name after canonical name, impeding the ability of the unauthorized software from traversing a network.
Techniques for impeding and detecting network threats
Reference - Trusted Communications With Child Processes - Microsoft Technology Licensing LLC
A method to identify a child process to a parent process in an operating system includes obtaining a token and login identifier from the operating system. The parent process creates a remote procedure call communications endpoint to communicate with the child process. Thereafter, a child process is spawned by the parent process. A child-initiated request to communicate with the parent process is then received by the parent process. In order to verify the identity of the child-initiated request, the parent process impersonates the child process and receives as identifier that identifies the requestor child process. The requestor process identifier and the spawned child identifier are compared. Based on the comparison, the parent process responds to the child-initiated request. In another embodiment, process identifiers are used by the parent process to verify the identity of a child process the requests communication with the parent process.
Kedarnath Atmaram Dubhashi, Jonathan D. Schwartz, Sambavi Muthukrishnan, Simon Skaria
This patent describes a technique for detecting malicious processes that claim to be the child process of a legitimate parent process. During the spawning of a child process, a child process identifier is generated. The child process identifier is a unique identifier that can be used to identify a child process. The child process identifier is transmitted by the security system of the operating system to the parent process. The parent process keeps track of the child process identifier. When a new child-initiated communications request is received by the parent process, the parent process checks if the requesting child process identifier and the child process identifier that the parent process is tracking are the same. If the identifiers are not the same, the parent process refuses the request.
Trusted Communications With Child Processes
Reference - Use Rkill to Stop Malware Processes - ghacks.net
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.
## 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).
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.
## 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).
A remote authentication service provides for the authentication of a user across a network (i.e., remotely).
A remote authorization service provides for the authorization of a user across a network (i.e., remotely).
A remote query session enabling a user to make an SQL, SPARQL, or similar query over the network from one host to another.
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.
A remote terminal session is a session that provides a user access from one host to another host via a terminal.
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.
## References Wikipedia contributors. (2021, August 23). Residual neural network. In Wikipedia, The Free Encyclopedia. [Link](https://en.wikipedia.org/wiki/Residual_neural_network)
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.
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.
## 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).
A saved instruction pointer points to the instruction that generated an exception (trap or fault).
An optional, often feature rich, second stage set of routines run in order to load the operating system.
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)
## References GeeksforGeeks. (n.d.). ANN - Self Organizing Neural Network (SONN). [Link](https://www.geeksforgeeks.org/ann-self-organizing-neural-network-sonn/)
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.
## 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/)
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.
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.
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.
Semi-supervised Generative Model Learning
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.
## References Weak supervision. Wikipedia. [Link](https://en.wikipedia.org/wiki/Weak_supervision#Generative_models).
The goal of inductive learning is to infer the correct mapping from X to Y
## 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).
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.
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
## 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.)
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.
## 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)
A function which has an operation that serializes data.
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.
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
## References Wikipedia. (n.d.). Singular value decomposition. [Link](https://en.wikipedia.org/wiki/Singular_value_decomposition)
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.
A software library is a collection of software components that are used to build a software product.
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.
Soundex is a phonetic algorithm for indexing names by sound, as pronounced in English.
## 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)
A source code analyzer tool is a static analysis tool that operates specifically on source code, but not object code.
Spectral clustering is a technique that identifies communities of nodes in a graph based on the edges connecting them.
## References Towards Data Science. (n.d.). Spectral Clustering. [Link](https://towardsdatascience.com/spectral-clustering-aba2640c0d5b)
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 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.
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.
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.
## 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)
A function which creates a new string based on a format specification and correspondingi specified values.
## References Wikipedia. (n.d.). StyleGAN. [Link](https://en.wikipedia.org/wiki/StyleGAN)
Subspace clustering is an extension of traditional clustering that seeks to find clusters in different subspaces within a dataset.
## 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)
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.
## References 1. String-searching algorithm. (2023, April 8). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/String-searching_algorithm)
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.
## 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).
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.
Symmetric Feature-based Transfer Learning
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.
## 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).
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).
A system initialization process is a process that executes to initialize (boot) an operating system.
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.
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.
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.
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.
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.
This technique has been revoked by T1560
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).
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.
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)
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)
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)
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.
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)
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.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)
This technique has been revoked by T1547.004
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.
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)
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.
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.
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.
This technique has been revoked by T1027.001
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)
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.
Adversaries may interact with the Windows Registry to gather information about the system, configuration, and installed software.
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.
This technique has been revoked by T1547.010
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)
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.
This technique has been revoked by T1546.008
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.
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.
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.
This technique has been revoked by T1072
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).
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)
This technique has been revoked by T1542.001
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)
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.
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.
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.
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.
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)
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.
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.
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 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.
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.
This technique has been revoked by T1547.009
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.
This technique has been revoked by T1573
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.
**This technique has been deprecated and should no longer be used.**
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.
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)
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.
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)
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.
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)
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.
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)
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)
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)
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)
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.
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.
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)
This technique has been revoked by T1021.006
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.
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.
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).
This technique has been revoked by T1543.003
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.
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.
**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).**
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.
This technique has been revoked by T1569.002
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)
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)
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)
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.
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.
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.
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)
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`.
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)
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)
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)
Group Policy Object / Active Directory Users and Computers are both Active Directory-based
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.
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)
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.
This technique has been revoked by T1574.001
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.
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.
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.
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.
This technique has been revoked by T1546.001
**This technique has been deprecated. Please use [Non-Standard Port](https://attack.mitre.org/techniques/T1571) where appropriate.**
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.
This technique has been revoked by T1574.010
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.
This technique has been revoked by T1027.002
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)
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 Symmetric Encrypted Non-C2 Protocol
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
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
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)
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.
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.
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.
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)
This technique has been revoked by T1053.002
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.
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.
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.
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[.
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)
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.
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).
This technique has been revoked by T1562.006
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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)
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)).
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.
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:
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.
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)
This technique has been revoked by T1574.011
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).
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.
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)
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.
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)
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)
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)
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.
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).
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)
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.
This technique has been revoked by T1547.001
**This technique has been deprecated. Please use [Remote Services](https://attack.mitre.org/techniques/T1021) where appropriate.**
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.
This technique has been revoked by T1518.001
**This technique has been deprecated. Please use [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059) where appropriate.**
Adversaries may conduct C2 communications over a non-standard port to bypass proxies and firewalls that have been improperly configured.
This technique has been revoked by T1571
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.
This technique has been revoked by T1027.005
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)
This technique has been revoked by T1542.003
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.
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.
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.
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.
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.
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)
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.
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.
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)
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
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.
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.
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)
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.
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.
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.
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.
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.
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)
This technique has been revoked by T1574.002
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.
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 (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.
This technique has been revoked by T1550.002
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.
This technique has been revoked by T1021.001
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$.
This technique has been revoked by T1021.002
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)
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)
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.
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)
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.
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.
This technique has been revoked by T1552.001
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.
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
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)
This technique has been revoked by T1546.003
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.
This technique has been revoked by T1218.011
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.
This technique has been revoked by T1059.001
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.
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)
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.
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)
This technique has been revoked by T1548.002
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.
This technique has been revoked by T1562.001
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.
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.
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.
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).
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.
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 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)
This technique has been revoked by T1055.012
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.
This technique has been revoked by T1095
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).
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)
This technique has been revoked by T1564.004
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.
This technique has been revoked by T1550.003
Adversaries may add adversary-controlled credentials to a cloud account to maintain persistent access to victim accounts and instances within the environment.
Adversaries may grant additional permission levels to maintain persistent access to an adversary-controlled email account.
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)
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.
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.
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)
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)
This technique has been revoked by T1070.006
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)
This technique has been revoked by T1505.003
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.
This technique has been revoked by T1547.005
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.
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.
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.
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)
This technique has been revoked by T1546.010
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.
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.
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.
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.
This technique has been revoked by T1070.004
**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.**
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.
This technique has been revoked by T1542.002
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.
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)
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)
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
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.
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.
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)
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.
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.
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)
Adversaries may collect data stored in the clipboard from users copying information within or between applications.
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)
This technique has been revoked by T1553.002
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)
This technique has been revoked by T1218.010
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.
This technique has been revoked by T1218.004
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.
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 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)
This technique has been revoked by T1218.009
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.
This technique has been revoked by T1546.015
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)
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)
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.
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)
This technique has been revoked by T1070.005
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)
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.
This technique has been revoked by T1546.007
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)).
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.
This technique has been revoked by T1553.004
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)
This technique has been revoked by T1547.002
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.
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)
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)
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)
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.
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)
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).
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.
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.
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)
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)
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)
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)
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)
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)
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)
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)
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.
This technique has been revoked by T1546.011
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)
This technique has been revoked by T1552.003
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.
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)).
This technique has been revoked by T1056.002
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.
This technique has been revoked by T1555.001
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.
This technique has been revoked by T1564.003
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.
This technique has been revoked by T1553.001
Private cryptographic keys and certificates are used for authentication, encryption/decryption, and digital signatures. (Citation: Wikipedia Public Key Crypto)
This technique has been revoked by T1552.004
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.
This technique has been revoked by T1070.003
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).
This technique has been revoked by T1564.002
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.
This technique has been revoked by T1562.003
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).
This technique has been revoked by T1547.011
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).
This technique has been revoked by T1036.006
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.
This technique has been revoked by T1569.001
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)
This technique has been revoked by T1546.005
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.
This technique has been revoked by T1059.002
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.
This technique has been revoked by T1546.004
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.
This technique has been revoked by T1574.004
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).
This technique has been revoked by T1564.001
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).
This technique has been revoked by T1543.001
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).
This technique has been revoked by T1543.004
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).
This technique has been revoked by T1546.006
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).
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.
This technique has been revoked by T1037.004
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.
This technique has been revoked by T1547.007
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.
This technique has been revoked by T1037.005
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].
This technique has been revoked by T1548.001
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)
This technique has been revoked by T1555.002
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).
This technique has been revoked by T1053
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).
This technique has been revoked by T1548.003
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)
This technique has been revoked by T1218.005
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)
This technique has been revoked by T1557.001
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).
This technique has been revoked by T1090.004
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.
This technique has been revoked by T1559.002
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.
This technique has been revoked by T1556.002
Component Object Model and Distributed COM
**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).**
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)
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)
This technique has been revoked by T1547.008
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).
This technique has been revoked by T1134.005
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.
This technique has been revoked by T1056.004
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.
This technique has been revoked by T1546.002
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)
This technique has been revoked by T1055.011
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)
This technique has been revoked by T1546.009
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)
This technique has been revoked by T1546.012
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.
This technique has been revoked by T1563.001
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)
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)
This technique has been revoked by T1055.013
Adversaries may gather credential material by invoking or forcing a user to automatically provide authentication information through a mechanism in which they can intercept.
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.
This technique has been revoked by T1090.003
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).
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.
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.
This technique has been revoked by T1218.003
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.
This technique has been revoked by T1566.002
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.
This technique has been revoked by T1566.001
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.
This technique has been revoked by T1566.003
Compromise Software Dependencies and Development Tools
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)
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.
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.
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)
This technique has been revoked by T1218.002
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.
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)
This technique has been revoked by T1553.003
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.
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.
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).
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)
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.
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).
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.
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)
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.
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.
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).
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.
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)
This technique has been revoked by T1558.003
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)
This technique has been revoked by T1547.003
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.
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.
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.
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:
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.
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.
This technique has been revoked by T1552.002
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)
This technique has been revoked by T1547.006
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)
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)
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)
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)
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.
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.
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.
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)
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.
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.
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)
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)
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}).
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)
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)
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)
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)
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)
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)
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)
Windows File and Directory Permissions Modification
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
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)
This technique has been revoked by T1218.001
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)
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)
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)
This technique has been revoked by T1568.002
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)
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.
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.
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)
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.
This technique has been revoked by T1561.002
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.
This technique has been revoked by T1561.001
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)
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.
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)
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)
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.
This technique has been revoked by T1565.001
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.
This technique has been revoked by T1565.002
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.
This technique has been revoked by T1565.003
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.
Adversaries may leverage the resources of co-opted systems to complete resource-intensive tasks, which may impact system and/or hosted service availability.
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)
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)
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.
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.
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.
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.
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.
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)
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.
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)
This technique has been revoked by T1027.004
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.
This technique has been revoked by T1543.002
This technique has been revoked by T1134.004
Adversaries may acquire credentials from web browsers by reading files specific to the target browser. (Citation: Talos Olympic Destroyer 2018)
This technique has been revoked by T1555.003
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)
This technique has been revoked by T1546.013
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).
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.
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)
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)
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)
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)
This technique has been revoked by T1550.004
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.
This technique has been revoked by T1548.004
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.
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)
This technique has been revoked by T1546.014
Adversaries may attempt to access the Cloud Instance Metadata API to collect credentials and other sensitive data.
This technique has been revoked by T1552.005
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)
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.
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.
This technique has been revoked by T1550.001
Adversaries can steal application access tokens as a means of acquiring credentials to access remote systems and resources.
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)
Adversaries may access data from cloud storage.
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)
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)
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.
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.
This technique has been revoked by T1578.004
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.
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)
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.
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)
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.
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.
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)
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.
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.
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.
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.
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)
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.
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.
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.
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)
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.
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.
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.
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.
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.
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)
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)
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)
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)
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.
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.
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.
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)
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.
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)
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)
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)
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.
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)
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.
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)
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.
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)
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)
This technique has been revoked by T1647
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)
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)
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.
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.
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.
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)
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.
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.
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.
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).
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.
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.
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.
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.
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.
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)
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.
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)
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)
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.
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 )
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.
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)
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.
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)
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.
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.
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.
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)
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.
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)
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)
Adversaries may acquire credentials from cloud-native secret management solutions such as AWS Secrets Manager, GCP Secret Manager, Azure Key Vault, and Terraform Vault.
Adversaries may patch the authentication process on a domain controller to bypass the typical authentication mechanisms and enable access to accounts.
Adversaries may register malicious password filter dynamic link libraries (DLLs) into the authentication process to acquire user credentials as they are validated.
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)
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.
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)
Adversaries may disable or modify multi-factor authentication (MFA) mechanisms to enable persistent access to compromised accounts.
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.
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)
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.
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.
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).
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).
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)
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)
Service Provider Name (SPN) scanning is one way to gather hashes, which results in RPC calls conforming to the NSPI protocol.
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)
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)
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.
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)
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.
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.
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)
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.
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.
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)
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.
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.
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.
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).
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).
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.
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)
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.
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.
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.
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.
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)
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).
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.
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.
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)
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)
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)
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)
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)
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)
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)
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.
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)
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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)
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)
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)
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)
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).
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.
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.
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.
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.
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.
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.
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).
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
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.
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
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
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.
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.
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.
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)
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)
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)
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)
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.
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)
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.
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.
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.
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.
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.
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.
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)
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)
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.
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.
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.
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)
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.
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)
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.
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).
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.
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.
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.
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)
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)
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)
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.
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)).
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)
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)
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.
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).
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)
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.
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)
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.
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.
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)
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)
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)
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.
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.
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.
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.
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)
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.
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.
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.
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.
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.
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.
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.
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.
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.).
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.).
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.).
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.
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.
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)
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.
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)
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.
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.
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)).
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.
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)
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.
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.
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)
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)
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.
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.
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.
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.
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.
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.
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)
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.
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.
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)
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).
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.
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.
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)
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.
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.
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)
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)).
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.
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)
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)
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)
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)
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)
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.
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)
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)
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.
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
Adversaries may attempt to bypass multi-factor authentication (MFA) mechanisms and gain access to accounts by generating MFA requests sent to users.
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)
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)
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
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)
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)
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)
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)).
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)
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)).
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.
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)
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)
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.
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.
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.
Temporal logic addresses the semantics of tense; i.e., qualifying expressions of when.
## References 1. Temporal logic. (2023, June 4). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Modal_logic#Temporal_logic)
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.
A function which invokes a create thread system call.
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.
## References Transformer-XL. (n.d.). Papers with Code. [Link](https://paperswithcode.com/method/transformer-xl)
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.
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.
A Unix hard link is a hard link on a Unix file system.
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).
A user startup directory holds information necessary to start the users session with the system.
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.
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.
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.
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
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.
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.
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.
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.
Creates, opens, reopens, or deletes a file.
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.
Creates a new process and its primary thread. The new process runs in the security context of the calling process.
Creates a thread to execute within the virtual address space of the calling process.
The DuplicateToken function creates a new access token that duplicates one already in existence.
Retrieves the context of the specified thread.
Windows NtSetInformationFile Argument FileDispositionInformation
Request to delete the file when it is closed or cancel a previously requested deletion.
Retrieves the current value of the performance counter, which is a high resolution (<1us) time stamp that can be used for time-interval measurements.
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.
Decrements a thread's suspend count. When the suspend count is decremented to zero, the execution of the thread is resumed.
Sets the context for the specified thread.
Terminates the specified process and all of its threads.
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.
Releases, decommits, or releases and decommits a region of pages within the virtual address space of the calling process.
Changes the protection on a region of committed pages in the virtual address space of a specified process.
Writes data to the specified file or input/output (I/O) device.
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.
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.
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.
x abuses y: The entity x applies an artifact y to a wrong thing or person; x applies y badly or incorrectly.
x attack-id y: The offensive technique x has the att&ck unique id of y.
date available
Date that the resource became or will become available.
Unique identifier for a CAPEC technique, i.e. a common attack pattern identified by the pattern CAPEC-[number].
x d3fend-display-property y: An object x should be displayed using the display property y, when it applies.
x definition y: The d3fend object x has the definition y.
x depends-on y: The entity x is contingent on y being available; x relies on y.
description
A statement that represents something in words.
A base string to use as prefix to create a full URL for an entity. The baseurl must end in a forward slash: /
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.
x employed-by y: An entity x is put into service by a technique or agent y. Inverse of y employs x.
identifier
date issued
Date of formal issuance of the resource.
x kb-abstract y: The reference x has the abstract y.
The technique x has the kb-article y, where y is written in Markdown.
x kb-author y: The reference x has some author y.
x kb-mitre-analysis y: The reference x has the mitre d3fend analysis y.
x kb-organization y: The reference x was created or owned by the organization y.
label
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.]
x pref-label y: The preferred display value for x is y in d3fend tools.
Procedure 1 - T1134.001 Access Token Manipulation
x process-parent y: The process y created the process x (directly) with a create process event.
x related y: x has a symmetric associative relation to y.
x release-date y: The object x has the release-date y.
The agent or technique x continues a previous action on entity y. Usually occurs after suspension on y.
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.
## References Wikipedia. (n.d.). T-distributed stochastic neighbor embedding. [Link](https://en.wikipedia.org/wiki/T-distributed_stochastic_neighbor_embedding)
text
The text of the document (i.e., terms of license.)
title
date valid
Date (often a range) of validity of a resource.
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.
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.
D3FEND™ - A knowledge graph of cybersecurity countermeasures
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.
An activity is a specific behavior representing a set of actions that may be accomplished by an agent.
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.
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.
A configuration of an application which is used to apply logical or data processing functions to data processed by the application.
Approximate string matching is a form of string matching that allows errrors.
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.
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.
## References Bootstrap aggregating. Wikipedia. [Link](https://en.wikipedia.org/wiki/Bootstrap_aggregating).
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.
## References Classification and Regression Tree (CART) Algorithm. Analytics Steps. [Link](https://www.analyticssteps.com/blogs/classification-and-regression-tree-cart-algorithm).
The organization employs automated mechanisms to support the information system account management functions.
The information system automatically removes or disables temporary accounts after an organization-defined time period for each type of account.
The information system automatically disables inactive accounts after an organization-defined time period.
The information system automatically audits account creation actions.
The information system dynamically manages user privileges and associated access authorizations.
The information system enforces one or more organization-defined nondiscretionary access control policies over an organization-defined set of users and resources.
The information system enforces information flow control using explicit security attributes on information, source, and destination objects as a basis for flow control decisions.
The information system enforces dynamic information flow control based on organization-defined policies.
The information system enforces organization-defined limitations on the embedding of data types within other data types.
The information system enforces information flow control based on organization-defined metadata.
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.
The information system provides the capability for a privileged administrator to enable/disable organization-defined security policy filters under organization-defined conditions.
The information system provides the capability for privileged administrators to configure the organization-defined security policy filters to support different security policies.
The organization implements separation of duties through assigned information system access authorizations.
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.
The information system enforces the organization-defined limit of consecutive invalid logon attempts by a user during the organization-defined time period.
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.
The information system retains the session lock until the user reestablishes access using established identification and authentication procedures.
The information system initiates a session lock after the organization-defined time period of inactivity.
The information system provides the capability for users to directly initiate session lock mechanisms.
The information system conceals, via the session lock, information previously visible on the display with a publicly viewable image.
The organization enforces requirements for remote connections to the information system.
The information system monitors remote access methods.
The information system implements cryptographic mechanisms to protect the confidentiality of remote access sessions.
The organization monitors for unauthorized remote connections to the information system on an organization-defined frequency.
The information system alerts designated organization-defined personnel or roles in the event of an audit processing failure.
The information system provides a warning when allocated audit record storage volume reaches an organization-defined percentage of maximum audit record storage capacity.
The information system provides a real-time alert when organization-defined audit failure events occur.
The information system protects audit information from unauthorized access.
The information system protects audit information from unauthorized modification.
The information system protects audit information from unauthorized deletion.
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.
The information system, for PKI-based authentication, enforces authorized access to the corresponding private key.
The information system, for PKI-based authentication, maps the authenticated identity to the account of the individual or group.
The information system enforces password complexity by the minimum number of upper case characters used.
The information system enforces password complexity by the minimum number of lower case characters used.
The information system enforces password complexity by the minimum number of numeric characters used.
The information system, for password-based authentication, when new passwords are created, enforces that at least an organization-defined number of characters are changed.
The information system, for password-based authentication, stores only cryptographically-protected passwords.
The information system, for password-based authentication, transmits only cryptographically-protected passwords.
The information system enforces minimum password lifetime restrictions.
The information system enforces maximum password lifetime restrictions.
The information system prohibits password reuse for the organization-defined number of generations.
The information system enforces minimum password length.
The information system enforces approved authorizations for logical access to information and system resources in accordance with applicable access control policies.
The information system, when transferring information between different security domains, identifies information flows by data type specification and usage.
The information system, when transferring information between different security domains, decomposes information into organization-defined policy-relevant subcomponents for submission to policy enforcement mechanisms.
The information system provides the capability for a privileged administrator to configure organization-defined security policy filters to support different security policies.
The organization employs automated mechanisms to enforce access restrictions.
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.
The organization employs automated mechanisms to respond to unauthorized changes to organization-defined configuration settings.
The organization configures the information system to provide only essential capabilities.
The organization configures the information system to prohibit or restrict the use of organization-defined functions, ports, protocols, and/or services.
The organization employs automated mechanisms to prevent program execution on the information system in accordance with the organization-defined specifications.
The organization disables network access by unauthorized components/devices or notifies designated organizational officials.
The organization (or information system) enforces explicit rules governing the installation of software by users.
The information system uniquely identifies and authenticates organizational users (or processes acting on behalf of organizational users).
The information system implements multifactor authentication for network access to privileged accounts.
The information system implements multifactor authentication for network access to non-privileged accounts.
The information system implements multifactor authentication for local access to privileged accounts.
The information system implements multifactor authentication for local access to non-privileged accounts.
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.
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.
The information system uses organization-defined replay-resistant authentication mechanisms for network access to privileged accounts.
The information system uses organization-defined replay-resistant authentication mechanisms for network access to non-privileged accounts.
The information system uniquely identifies and authenticates non-organizational users (or processes acting on behalf of non-organizational users).
The organization implements a configurable capability to automatically disable the information system if organization-defined security violations are detected.
The organization employs strong authenticators in the establishment of nonlocal maintenance and diagnostic sessions.
The organization audits non-local maintenance and diagnostic sessions.
The organization protects nonlocal maintenance sessions by employing organization-defined authenticators that are replay resistant.
The organization employs cryptographic mechanisms to protect the integrity and confidentiality of non-local maintenance and diagnostic communications.
The information system uses cryptographic mechanisms to protect and restrict access to information on portable digital media.
The organization employs cryptographic mechanisms to protect information in storage.
The information system implements privileged access authorization to organization-identified information system components for selected organization-defined vulnerability scanning activities.
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.
The information system separates user functionality (including user interface services) from information system management functionality.
The information system prevents the presentation of information system management-related functionality at an interface for non-privileged users.
The information system isolates security functions from nonsecurity functions.
The information system utilizes underlying hardware separation mechanisms to implement security function isolation.
The information system isolates security functions enforcing access and information flow control from both nonsecurity functions and from other security functions.
The organization implements an information system isolation boundary to minimize the number of nonsecurity functions included within the boundary containing security functions.
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.
The information system prevents unauthorized and unintended information transfer via shared system resources.
The information system protects against or limits the effects of the organization-defined or referenced types of denial of service attacks.
The information system restricts the ability of individuals to launch organization-defined denial of service attacks against other information systems.
The information system limits the use of resources by priority.
The information system prevents public access into the organization's internal networks except as appropriately mediated by managed interfaces employing boundary protection devices.
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).
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.
The information system, at managed interfaces, denies network traffic and audits internal users (or malicious code) posing a threat to external information systems.
The information system checks incoming communications to ensure the communications are coming from an authorized source and routed to an authorized destination.
The information system implements host-based boundary protection mechanisms for servers, workstations, and mobile devices.
The information system prevents discovery of specific system components composing a managed interface.
The information system enforces adherence to protocol format.
The information system protects the integrity of transmitted information.
The organization employs cryptographic mechanisms to recognize changes to information during transmission unless otherwise protected by alternative physical measures.
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.
The information system implements required cryptographic protections using cryptographic modules that comply with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.
The organization employs, at a minimum, FIPS-validated cryptography to protect unclassified information.
The organization employs NSA-approved cryptography to protect classified information.
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.
The information system prohibits remote activation of collaborative computing devices, excluding the organization-defined exceptions where remote activation is to be allowed.
The information system identifies organization-defined unacceptable mobile code.
The information system prevents the download of organization-defined unacceptable mobile code.
The information system prevents the automatic execution of mobile code in organization-defined software applications.
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.
The information system invalidates session identifiers upon user logout or other session termination.
The information system protects the confidentiality and/or integrity of organization-defined information at rest.
The organization employs cryptographic mechanisms to prevent unauthorized disclosure of information at rest unless otherwise protected by alternative physical measures.
The information system, at organization-defined information system components, loads and executes the operating environment from hardware-enforced, read-only media.
The information system, at organization-defined information system components, loads and executes organization-defined applications from hardware-enforced, read-only media.
The organization employs automated mechanisms on an organization-defined frequency to determine the state of information system components with regard to flaw remediation.
The organization employs automated patch management tools to facilitate flaw remediation to organization-defined information system components.
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.
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.
The information system monitors inbound and outbound communications for unusual or unauthorized activities or conditions.
The information system detects unauthorized changes to software and information.
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.
The information system checks the validity of organization-defined inputs.
The information system implements cryptographic mechanisms to protect the integrity of audit information.
The organization protects the audit records of non-local accesses to privileged accounts and the execution of privileged functions.
The organization monitors for atypical usage of information system accounts.
The information system enforces approved authorizations for controlling the flow of information within the system based on organization-defined information flow control policies.
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.
The information system, when transferring information between different security domains, examines the information for the presence of organization-defined unsanctioned information.
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.
The information system uniquely identifies source domains for information transfer.
The information system uniquely authenticates source domains for information transfer.
The information system supports and maintains the binding of organization-defined security attributes to information in storage.
The information system supports and maintains the binding of organization-defined security attributes to information in process.
The information system supports and maintains the binding of organization-defined security attributes to information in transmission.
The information system automatically audits account modification actions.
The information system automatically audits account disabling actions.
The information system automatically audits account removal actions.
The information system enforces approved authorizations for controlling the flow of information between interconnected systems based on organization-defined information flow control policies.
The information system dynamically associates security attributes with organization-defined subjects in accordance with organization-defined security policies as information is created and combined.
The information system provides authorized individuals (or processes acting on behalf of individuals) the capability to change the value of associated security attributes.
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.
The information system allows authorized users to associate security attributes with information.
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.
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.
The information system enforces the organization-defined time period during which the limit of consecutive invalid access attempts by a user is counted.
The information system implements cryptographic mechanisms to protect the integrity of remote access sessions.
The organization ensures that remote sessions for accessing an organization-defined list of security functions and security-relevant information are audited.
The information system protects audit tools from unauthorized access.
The information system protects audit tools from unauthorized modification.
The information system protects audit tools from unauthorized deletion.
The information system implements cryptographic mechanisms to protect the integrity of audit tools.
The organization limits privileges to change software resident within software libraries.
The information system uniquely identifies destination domains for information transfer.
The information system uniquely authenticates destination domains for information transfer.
The information system tracks problems associated with the information transfer.
The information system rejects or delays, as defined by the organization, network traffic which exceed the organization-defined thresholds.
The organization incorporates detection of unauthorized, security-relevant configuration changes into the organization‚Äôs incident response capability to ensure they are tracked.
The information system enforces password complexity by the minimum number of special characters used.
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.
The information system takes organization-defined corrective action when organization-defined unacceptable mobile code is identified.
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.
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.
The information system automatically removes or disables emergency accounts after an organization-defined time period for each type of account.
The information system notifies organization-defined personnel or roles for account creation actions.
The information system notifies organization-defined personnel or roles for account modification actions.
The information system notifies organization-defined personnel or roles for account disabling actions.
The information system notifies organization-defined personnel or roles for account removal actions.
The information system prevents the execution of organization-defined unacceptable mobile code.
The information system implements organization-defined security responses automatically if baseline configurations are changed in an unauthorized manner.
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.
The organization disables organization-defined functions, ports, protocols, and services within the information system deemed to be unnecessary and/or nonsecure.
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.
The organization employs an allow-all, deny-by-exception policy to prohibit the execution of unauthorized software programs on the information system.
The organization employs a deny-all, permit-by-exception policy to allow the execution of authorized software programs on the information system.
The information system alerts organization-defined personnel or roles when the unauthorized installation of software is detected.
The information system prohibits user installation of software without explicit privileged status.
The information system enforces access restrictions.
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.
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.
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.
The device used in the information system implementation of multifactor authentication for network access to privileged accounts meets organization-defined strength of mechanism requirements.
The information system implements replay-resistant authentication mechanisms for network access to privileged accounts.
The information system accepts Personal Identity Verification (PIV) credentials.
The information system electronically verifies Personal Identity Verification (PIV) credentials.
The information system implements organization-defined out-of-band authentication under organization-defined conditions.
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.
The information system, for biometric-based authentication, employs mechanisms that satisfy organization-defined biometric quality requirements.
The information system accepts Personal Identity Verification (PIV) credentials from other federal agencies.
The information system electronically verifies Personal Identity Verification (PIV) credentials from other federal agencies.
The information system accepts Personal Identity Verification-I (PIV-I) credentials.
The information system electronically verifies Personal Identity Verification-I (PIV-I) credentials.
The information system allows the use of a temporary password for system logons with an immediate change to a permanent password.
The information system enforces organization-defined circumstances and/or usage conditions for organization-defined information system accounts.
The information system enforces organization-defined discretionary access control policies over defined subjects and objects.
The information system enforces a role-based access control policy over defined subjects and objects.
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.
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.
The information system, when transferring information between different security domains, uses organization-defined data type identifiers to validate data essential for information flow decisions.
The information system uniquely identifies and authenticates source by organization, system, application, and/or individual for information transfer.
The information system uniquely identifies and authenticates destination by organization, system, application, and/or individual for information transfer.
The information system, when transferring information between different security domains, applies the same security policy filtering to metadata as it applies to data payloads.
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.
The information system prevents organization-defined software from executing at higher privilege levels than users executing the software.
The information system prevents non-privileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures.
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.
The organization provides the means to associate organization-defined types of security attributes having organization-defined security attribute values with information in storage.
The organization provides the means to associate organization-defined types of security attributes having organization-defined security attribute values with information in process.
The organization provides the means to associate organization-defined types of security attributes having organization-defined security attribute values with information in transmission.
The information system dynamically associates security attributes with organization-defined objects in accordance with organization-defined security policies as information is created and combined.
The information system provides authorized individuals (or processes acting on behalf of individuals) the capability to define the value of associated security attributes.
The information system maintains the association of organization-defined security attributes to organization-defined subjects.
The information system maintains the association of organization-defined security attributes to organization-defined objects.
The information system maintains the integrity of organization-defined security attributes associated with organization-defined subjects.
The information system maintains the integrity of organization-defined security attributes associated with organization-defined objects.
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).
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).
The information system implements organization-defined techniques or technologies with an organization-defined level of assurance in associating security attributes to information.
The information system provides authorized individuals the capability to define or change the type of security attributes available for association with subjects.
The information system provides authorized individuals the capability to define or change the value of security attributes available for association with subjects.
The information system provides authorized individuals the capability to define or change the type of security attributes available for association with objects.
The information system provides authorized individuals the capability to define or change the value of security attributes available for association with objects.
The organization provides the capability to expeditiously disconnect or disable remote access to the information system within the organization-defined time period.
The organization employs organization-defined data mining prevention techniques for organization-defined data storage objects to adequately protect against data mining.
The organization employs organization-defined data mining detection techniques for organization-defined data storage objects to adequately detect data mining attempts.
The information system transmits organization-defined access authorization information using organization-defined security safeguards to organization-defined information systems which enforce access control decisions.
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.
The information system implements a reference monitor for organization-defined access control policies that is tamperproof.
The information system implements a reference monitor for organization-defined access control policies that is always invoked.
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.
The information system automatically terminates a user session after organization-defined conditions or trigger events requiring session disconnect.
The information system provides a logout capability for user-initiated communications sessions whenever authentication is used to gain access to organization-defined information resources.
The information system displays an explicit logout message to users indicating the reliable termination of authenticated communications sessions.
The organization minimizes the number of nonsecurity functions included within the isolation boundary containing security functions.
The organization implements security functions as largely independent modules that maximize internal cohesiveness within modules and minimize coupling between modules.
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.
The information system protects against or limits the effects of organization-defined types of denial of service attacks by employing organization-defined security safeguards.
The information system protects the availability of resources by allocating organization-defined resources based on priority, quota, and/or organization-defined security safeguards.
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.
The information system audits the identity of internal users associated with denied outgoing communications traffic posing a threat to external information systems.
The information system only allows incoming communications from organization-defined authorized sources routed to organization-defined authorized destinations.
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.
The information system provides the capability to dynamically isolate/segregate organization-defined information system components from other components of the system.
The information system maintains the confidentiality and/or integrity of information during preparation for transmission.
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.
The information system maintains the confidentiality and/or integrity of information during reception.
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.
The information system implements cryptographic mechanisms to conceal or randomize communication patterns unless otherwise protected by organization-defined alternative physical safeguards.
The information system provides a trusted communications path that is logically isolated and distinguishable from other paths.
The information system enforces organization-defined actions prior to executing mobile code.
The information system provides additional data integrity verification artifacts along with the authoritative name resolution data the system returns in response to external name/address resolution queries.
The information system provides data origin artifacts for internal name/address resolution queries.
The information system provides data integrity protection artifacts for internal name/address resolution queries.
The information system requests data origin authentication verification on the name/address resolution responses the system receives from authoritative sources.
The information system requests data integrity verification on the name/address resolution responses the system receives from authoritative sources.
The information system performs data integrity verification on the name/address resolution responses the system receives from authoritative sources.
The information system performs data origin verification authentication on the name/address resolution responses the system receives from authoritative sources.
The information system only allows the use of organization-defined certificate authorities for verification of the establishment of protected sessions.
The information system implements cryptographic mechanisms to prevent unauthorized modification of organization-defined information at rest on organization-defined information system components.
The information system implements cryptographic mechanisms to prevent unauthorized disclosure of organization-defined information at rest on organization-defined information system components.
The information system maintains a separate execution domain for each executing process.
The information system implements underlying hardware separation mechanisms to facilitate process separation.
The information system maintains a separate execution domain for each thread in organization-defined multi-threaded processing.
The information system protects organization-defined external and internal wireless links from organization-defined types of signal parameter attacks or references to sources for such attacks.
The organization physically disables or removes organization-defined connection ports or input/output devices on organization-defined information systems or information system components.
The organization installs security-relevant software updates within an organization-defined time period of the release of the updates.
The organization installs security-relevant firmware updates within an organization-defined time period of the release of the updates.
The organization installs organization-defined security-relevant software updates automatically to organization-defined information system components.
The organization installs organization-defined security-relevant firmware updates automatically to organization-defined information system components.
The organization removes organization-defined software components (e.g., previous versions) after updated versions have been installed.
The organization removes organization-defined firmware components (e.g., previous versions) after updated versions have been installed.
The information system detects organization-defined unauthorized operating system commands through the kernel application programming interface at organization-defined information system hardware components.
The information system issues a warning, audits the command execution, or prevents the execution of the command when organization-defined unauthorized operating system commands are detected.
The information system monitors inbound communications traffic per organization-defined frequency for unusual or unauthorized activities or conditions.
The information system monitors outbound communications traffic per organization-defined frequency for unusual or unauthorized activities or conditions.
The information system audits and/or alerts organization-defined personnel when unauthorized network services are detected.
The information system discovers indicators of compromise.
The information system collects indicators of compromise.
The information system distributes indicators of compromise.
The information system uses indicators of compromise.
The information system performs an integrity check of organization-defined software at startup, at organization-defined transitional states or security-relevant events, or on an organization-defined frequency.
The information system performs an integrity check of organization-defined firmware at startup, at organization-defined transitional states or security-relevant events, or on an organization-defined frequency.
The information system performs an integrity check of organization-defined information at startup, at organization-defined transitional states or security-relevant events, or on an organization-defined frequency.
The information system automatically shuts the information system down, restarts the information system, and/or implements organization-defined security safeguards when integrity violations are discovered.
The information system implements cryptographic mechanisms to detect unauthorized changes to software.
The information system implements cryptographic mechanisms to detect unauthorized changes to firmware.
The information system implements cryptographic mechanisms to detect unauthorized changes to information.
The information system, upon detection of a potential integrity violation, provides the capability to audit the event.
The information system, upon detection of a potential integrity violation, initiates one or more of the following actions: generates an audit record; alerts the current user; alerts organization-defined personnel or roles; and/or organization-defined other actions.
The information system verifies the integrity of the boot process of organization-defined devices.
The information system implements organization-defined security safeguards to protect the integrity of boot firmware in organization-defined devices.
The information system implements cryptographic mechanisms to authenticate organization-defined software or firmware components prior to installation.
The information system implements spam protection mechanisms with a learning capability to more effectively identify legitimate communications traffic.
The information system provides a manual override capability for input validation of organization-defined inputs.
The information system restricts the use of the manual override capability to only organization-defined authorized individuals.
The information system audits the use of the manual override capability.
The information system validates information output from organization-defined software programs and/or applications to ensure that the information is consistent with the expected content.
The information system implements organization-defined security safeguards to protect its memory from unauthorized code execution.
The information system restricts the use of maintenance tools to authorized personnel only.
The information system implements cryptographic mechanisms to protect the integrity of nonlocal maintenance and diagnostic communications.
The information system implements remote disconnect verification at the termination of nonlocal maintenance and diagnostic sessions.
The information system enforces organization-defined mandatory access control policies over all subjects and objects.
The information system implements cryptographic mechanisms to protect the confidentiality of nonlocal maintenance and diagnostic communications.
Insufficient Encapsulation of Machine-Dependent Functionality
Incorrect Access of Indexable Resource ('Range Error')
Insecure Default Initialization of Resource
Improper Isolation of Shared Resources on System-on-a-Chip (SoC)
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Generation of Weak Initialization Vector (IV)
Insufficient Granularity of Access Control
Improper Validation of Syntactic Correctness of Input
Improper Protection of Physical Side Channels
Insufficient or Incomplete Data Removal within Hardware Component
Multiple Releases of Same Resource or Handle
Improper Neutralization of Input Terminators
Improper Neutralization of Wildcards or Matching Symbols
Improper Neutralization of Multiple Leading Special Elements
Improper Neutralization of Internal Special Elements
Insertion of Sensitive Information Into Sent Data
Storage of File with Sensitive Data Under Web Root
Omission of Security-relevant Information
Improper Handling of Inconsistent Structural Elements
Improper Check for Certificate Revocation
Incorrect Implementation of Authentication Algorithm
Insufficient UI Warning of Dangerous Operations
Time-of-check Time-of-use (TOCTOU) Race Condition
Path Equivalence: 'filename.' (Trailing Dot)
Path Equivalence: 'file.name' (Internal Dot)
Use of Function with Inconsistent Implementations
Critical Public Variable Without Final Modifier
Use of Cache Containing Sensitive Information
Reliance on Cookies without Validation and Integrity Checking
Comparison of Object References Instead of Object Contents
Authorization Bypass Through User-Controlled Key
Function Call With Incorrectly Specified Argument Value
Compiler Optimization Removal or Modification of Security-critical Code
Failure to Sanitize Special Elements into a Different Plane (Special Element Injection)
Missing Reference to Active Allocated Resource
Buffer Access with Incorrect Length Value
Signal Handler with Functionality that is not Asynchronous-Safe
Improper Neutralization of Script in Attributes in a Web Page
Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
Improperly Controlled Modification of Dynamically-Determined Object Attributes
Improper Neutralization of CRLF Sequences ('CRLF Injection')
Improper Verification of Source of a Communication Channel
Improper Neutralization of Directives in Statically Saved Code ('Static Code Injection')
A catalog is a complete list of things; usually arranged systematically.
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.
## References Google Developers. (n.d.). Clustering Algorithms. [Link](https://developers.google.com/machine-learning/clustering/clustering-algorithms)
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 .
## References Wikipedia. (n.d.). Coefficient of variation. [Link](https://en.wikipedia.org/wiki/Coefficient_of_variation)
Correlation clustering provides a method for clustering a set of objects into the optimum number of clusters without specifying that number in advance.
## References Wikipedia. (n.d.). Correlation clustering. [Link](https://en.wikipedia.org/wiki/Correlation_clustering)
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.
A description logic (DL) is a form of logic usually more expressive than propositional logic but less expressive than first-order logic.
## 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)
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.
A digital object is the top-level class for an object that exists in a digital environment. The digital object may be virtual or physical.
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.
## References AnalytixLabs. (n.d.). Types of Clustering Algorithms. [Link](https://www.analytixlabs.co.in/blog/types-of-clustering-algorithms/#:~:text=Distribution-Based)
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.
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.
Blocking a DNS lookup's answer's IP address value.
## 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 order to determine the IP address(es) in the response. * Replacing the response is not effective in the case that the nameserver uses a technique to provide integrity of its responses, such as DNSSEC for DNS responses.
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.
## References Wikipedia. (n.d.). Central tendency. [Link](https://en.wikipedia.org/wiki/Central_tendency)
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.
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.
Initiating a host's reboot sequence to terminate all running processes.
## 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.
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.
Generic function that receives input from an untrusted source.
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.
## References Wikipedia. (n.d.). Interquartile range. [Link](https://en.wikipedia.org/wiki/Interquartile_range)
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.
The measure of the "fatness" of the tails of a pmf or pdf. The fourth standardized moment of the distribution.
## References Wikipedia. (n.d.). Probability distribution. [Link](https://en.wikipedia.org/wiki/Probability_distribution)
Mail traffic is network traffic that uses a standard mail transfer protocol.
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.
The sum of all measurements divided by the number of observations in the data set.
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.
## References Wikipedia. (n.d.). Average absolute deviation. [Link](https://en.wikipedia.org/wiki/Average_absolute_deviation)
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.
The median absolute deviation (also MAD) is the median of the absolute deviation from the median.
A memory address space is a space containing memory addresses.
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.
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.
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.
## References Wikipedia. (n.d.). Moment (mathematics). [Link](https://en.wikipedia.org/wiki/Moment_(mathematics))
Remote Access | Disable Nonsecure Network Protocols
Access Control Decisions | Transmit Access Authorization Information
Access Control Decisions | No User or Process Identity
Account Management | Automated System Account Management
Account Management | Disable Accounts for High-risk Individuals
Account Management | Automated Temporary and Emergency Account Management
Account Management | Automated Audit Actions
Account Management | Dynamic Privilege Management
Account Management | Privileged User Accounts
Account Management | Restrictions on Use of Shared and Group Accounts
Access Enforcement | Restrict Access to Specific Information Types
Access Enforcement | Attribute-based Access Control
Access Enforcement | Mandatory Access Control
Access Enforcement | Role-based Access Control
Access Enforcement | Revocation of Access Authorizations
Information Flow Enforcement | Object Security and Privacy Attributes
Information Flow Enforcement | Enable and Disable Security or Privacy Policy Filters
Information Flow Enforcement | Configuration of Security or Privacy Policy Filters
Information Flow Enforcement | Data Type Identifiers
Information Flow Enforcement | Decomposition into Policy-relevant Subcomponents
Information Flow Enforcement | Security or Privacy Policy Filter Constraints
Information Flow Enforcement | Detection of Unsanctioned Information
Information Flow Enforcement | Domain Authentication
Information Flow Enforcement | Validation of Metadata
Information Flow Enforcement | Approved Solutions
Information Flow Enforcement | Physical or Logical Separation of Information Flows
Information Flow Enforcement | Audit Filtering Actions
Information Flow Enforcement | Redundant/independent Filtering Mechanisms
Information Flow Enforcement | Linear Filter Pipelines
Information Flow Enforcement | Filter Orchestration Engines
Information Flow Enforcement | Dynamic Information Flow Control
Information Flow Enforcement | Filter Mechanisms Using Multiple Processes
Information Flow Enforcement | Process Requirements for Information Transfer
Information Flow Enforcement | Flow Control of Encrypted Information
Information Flow Enforcement | Embedded Data Types
Information Flow Enforcement | Security and Privacy Policy Filters
Least Privilege | Authorize Access to Security Functions
Least Privilege | Prohibit Non-privileged Users from Executing Privileged Functions
Least Privilege | Network Access to Privileged Commands
Least Privilege | Separate Processing Domains
Least Privilege | Privileged Access by Non-organizational Users
Least Privilege | Log Use of Privileged Functions
Unsuccessful Logon Attempts | Biometric Attempt Limiting
Unsuccessful Logon Attempts | Use of Alternate Authentication Factor
Session Audit | Capture and Record Content
Event Logging | Compilation of Audit Records from Multiple Sources
Event Logging | Selection of Audit Events by Component
Access Restrictions for Change | Automated Access Enforcement and Audit Records
Access Restrictions for Change | Signed Components
Access Restrictions for Change | Privilege Limitation for Production and Operation
Access Restrictions for Change | Limit Library Privileges
Configuration Settings | Unauthorized Change Detection
Identification and Authentication (organizational Users) | Multi-factor Authentication to Privileged Accounts
Identification and Authentication (organizational Users) | Multi-factor Authentication to Non-privileged Accounts
Identification and Authentication (organizational Users) | Local Access to Non-privileged Accounts
Identification and Authentication (organizational Users) | Access to Accounts —separate Device
Incident Handling | Malicious Code and Forensic Analysis
Maintenance Tools | Prevent Unauthorized Removal
Maintenance Tools | Execution with Privilege
Maintenance Tools | Software Updates and Patches
Nonlocal Maintenance | Logging and Review
Timely Maintenance | Preventive Maintenance
Timely Maintenance | Predictive Maintenance
Timely Maintenance | Automated Support for Predictive Maintenance
Risk Assessment | Dynamic Threat Awareness
Risk Assessment | Predictive Cyber Analytics
Vulnerability Monitoring and Scanning | Update Vulnerabilities to Be Scanned
Vulnerability Monitoring and Scanning | Breadth and Depth of Coverage
Vulnerability Monitoring and Scanning | Discoverable Information
Vulnerability Monitoring and Scanning | Privileged Access
Vulnerability Monitoring and Scanning | Automated Trend Analyses
Vulnerability Monitoring and Scanning | Automated Detection and Notification of Unauthorized Components
Developer Configuration Management | Software and Firmware Integrity Verification
Developer Configuration Management | Hardware Integrity Verification
Developer Configuration Management | Trusted Generation
Developer Configuration Management | Mapping Integrity for Version Control
Developer Configuration Management | Trusted Distribution
Developer Testing and Evaluation | Static Code Analysis
Developer Testing and Evaluation | Dynamic Code Analysis
Security and Privacy Engineering Principles | Trusted Communications Channels
Security and Privacy Engineering Principles | Accountability and Traceability
Separation of System and User Functionality
Separation of System and User Functionality | Interfaces for Non-privileged Users
Security Function Isolation | Hardware Separation
Flaw Remediation | Automated Patch Management Tools
Flaw Remediation | Automatic Software and Firmware Updates
Flaw Remediation | Removal of Previous Versions of Software and Firmware
Malicious Code Protection | Malicious Code Analysis
Malicious Code Protection | Updates Only by Privileged Users
Malicious Code Protection | Detect Unauthorized Commands
System Monitoring | Automated Tools and Mechanisms for Real-time Analysis
System Monitoring | Inbound and Outbound Communications Traffic
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.
CNSSI 4009 aka "Committee on National Security Systems (CNSS) Glossary" (March 2, 2002)
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.
The objective of a Reinforcement Learning Policy Gradient agent is to maximize the “expected” reward when following a policy
## References Policy Gradients in a Nutshell. Towards Data Science. [Link](https://towardsdatascience.com/policy-gradients-in-a-nutshell-8b72f9743c5d).
Projection Based Clustering is a clustering framework based on a chosen projection method and projection method a parameter-free high-dimensional data visualization technique.
## 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)
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.
## References Q-learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Q-learning).
The range of a set of data is the difference between the largest and smallest value.
## References Wikipedia. (n.d.). Range (statistics). [Link](https://en.wikipedia.org/wiki/Range_(statistics))
Reference - CAR-2019-07-001: Access Permission Modification - MITRE
Adversaries sometimes modify object access rights at the operating system level. There are varying motivations behind this action - they may not want some files/objects to be changed on systems for persistence reasons and therefore provide admin only rights; also, they may want files to be accessible with lower levels of permissions.
CAR-2019-07-001: Access Permission Modification
Reference - Account monitoring - Forescout Technologies
Systems, methods, and related technologies for account access monitoring are described. In certain aspects, a login request associated with a device can be analyzed and a score determined. The score and a threshold can be used to determine whether to initiate an action.
Reference - CAR-2019-08-002: Active Directory Dumping via NTDSUtil - MITRE
The NTDSUtil tool may be used to dump a Microsoft Active Directory database to disk for processing with a credential access tool such as Mimikatz. This is performed by launching ntdsutil.exe as a privileged user with command line arguments indicating that media should be created for offline Active Directory installation and specifying a folder path. This process will create a copy of the Active Directory database, ntds.dit, to the specified folder path.
CAR-2019-08-002: Active Directory Dumping via NTDSUtil
Reference - Advanced device matching system
Disclosed is a device management system for discovery and management of components added to computer systems and sub-systems. The device management system provides for recognizing a newly added component, and determining if the newly added component is already a part of the system inventory. The newly added component is matched with a component currently on the system, based on at least one matching attribute. A point total is calculated for each match level and a final match score is provided. The match score is compared with an aggressiveness level to determine if a match does indeed exist.
Rajneesh Jalan, Joseph M. Schmitt, and Marco Simoes
Reference - CAR-2015-07-001: All Logins Since Last Boot - MITRE
Once a credential dumper like mimikatz runs, every user logged on since boot is potentially compromised, because the credentials were accessed via the memory of lsass.exe. 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. The time field indicates the first and last time a system reported a user logged into a given system. This means that activity could be intermittent between the times given and should not be considered a duration.
CAR-2015-07-001: All Logins Since Last Boot
Reference - Analysis of the Windows Vista Security Model - Symantec Corporation
This paper provides an in-depth technical assessment of the security improvements implemented in Windows Vista, focusing primarily on the areas of User Account Protection and User Interface Privilege Isolation. This paper discusses these features and touches on several of their shortcomings. It then demonstrates how it is possible to combine these attacks to gain full control over the machine from low integrity, low privilege process.
Analysis of the Windows Vista Security Model
Reference - Anomaly Detection Using Adaptive Behavioral Profiles - Securonix Inc
The invention provides a system and method for automatic creation of adaptive behavioral profiles for observables associated with resource states and events in a computer network (IT) infrastructure of an enterprise and for detecting anomalies that represent potential malicious activity and threats as deviations from normal behavior. Separate profiles may be created for each behavioral indicator, as well as for each time series of measurements, and aggregated to create an overall behavioral profile. An anomaly probability is determined from the behavioral profile and used to evaluate the data values of observables. Outlier data values which deviate from normal behavior by more than a predetermined probability threshold are identified for risk analysis as possible threats while inliers within the range of normal behavior are used to update the behavioral profile. Behavioral profiles are created for behavioral indicators based upon observables measured over predetermined time periods using algorithms employing statistical analysis approaches that work for any type of data distribution, and profiles are adapted over time using data aging to more closely represent current behavior. Algorithm parameters for creating profiles are based on the type of data, i.e., its metadata.
Igor A. Baikalov; Tanuj Gulati; Sachin Nayyar; Anjaneya Shenoy; Ganpatrao H. Patwardhan
The patent describes a technique for detecting anomalous activity within an organization's IT infrastructure to identify threats. Behavioral profiles can be grouped by peer groups that identify functionally similar groups of actors (users or resources) based on their attributes and pre-defined grouping rules. For example, users can be grouped by their job title, organizational hierarchy, or location and can be observed for similarities in access patterns, based on granted access entitlements or actual logged resource access. Behavioral profiles are created from measurements of events over a time period for example: * Transaction counts * Concurrent users per hour * Daily volume of data Outlier data values which deviate from behavioral profile by more than a predetermined probability threshold are identified for risk analysis as possible threats.
Anomaly Detection Using Adaptive Behavioral Profiles
Reference - Anti-tamper system with self-adjusting guards - ARXAN TECHNOLOGIES Inc
An anti-tamper system is disclosed that includes self-adjusting guards inserted in software. Self-adjusting guards include invocation criteria and guard function. During run-time, each time the self-adjusting guard is invoked, the invocation criteria is evaluated and the guard function is only executed if the invocation criteria is satisfied. The invocation criteria can be static or dynamic, satisfied randomly with fixed or varying probability, a monotonically or exponentially decreasing function or most any other type of function. The invocation criteria can be satisfied based on elapsed inter-guard invocation time (time since last guard function execution), target inter-guard invocation time, and/or guard execution time. A method is disclosed of inserting self-adjusting guards into software, and executing the software. Evaluating the invocation criteria can include adjusting the invocation criteria when satisfied. The self-adjusting guards can be inserted into the software at a source or object code level.
Anti-tamper system with self-adjusting guards
Reference - Approaches for securing an internet endpoint using fine-grained operating system virtualization - Bromium, Inc.
Approaches for executing untrusted software on a client without compromising the client using micro-virtualization to execute untrusted software in isolated contexts. A template for instantiating a virtual machine on a client is identified in response to receiving a request to execute an application. After the template is identified, without human intervention, a virtual machine is instantiated, using the template, in which the application is to be executed. The template may be selected from a plurality of templates based on the nature of the request, as each template describe characteristics of a virtual machine suitable for a different type of activity. Selected resources such as files are displayed to the virtual machines according to user and organization policies and controls. When the client determines that the application has ceased to execute, the client ceases execution of the virtual machine without human intervention.
Gaurav Banga, Ian Pratt, Kiran Bondalapati, Vikram Kapoor
Approaches for securing an internet endpoint using fine-grained operating system virtualization
Reference - Architecture of transparent network security for application containers - Neuvector Inc
A system comprises one or more application containers, each application container including computer-readable instructions and initiated via a container service and isolated using operating system-level virtualization. The system also comprises one or more virtual switches configured to route traffic from the application containers. The system further comprises one or more security containers, each security container configured to transparently intercept traffic from the one or more application containers for analysis of network security. The system further comprises a user interface (UI) container configured to receive configuration settings from a user. The system also comprises an analytics container configured to perform analysis on data received from the one or more security containers. The system also comprises a management container configured to configure settings for the one or more security containers and the analytics container.
Architecture of transparent network security for application containers
Reference - Automated computer vulnerability resolution system
A system and process for addressing computer security vulnerabilities. The system and process generally comprise aggregating vulnerability information on a plurality of computer vulnerabilities; constructing a remediation database of said plurality of computer vulnerabilities; constructing a remediation signature to address the computer vulnerabilities; and deploying said remediation signature to a client computer. The remediation signature essentially comprises a sequence of actions to address a corresponding vulnerability. A managed automated approach to the process is contemplated in which the system is capable of selective deployment of remediation signatures; selective resolution of vulnerabilities; scheduled deployment of remediation signatures; and scheduled scanning of client computers for vulnerabilities.
Automated computer vulnerability resolution system
Reference - Automatically generating network resource groups and assigning customized decoy policies thereto - Illusive Networks Ltd
A cyber security system comprising circuitry of a decoy deployer planting one or more decoy lateral attack vectors in each of a first and a second group of resources within a common enterprise network of resources, the first and second groups of resources having different characteristics in terms of subnets, naming conventions, DNS aliases, listening ports, users and their privileges, and installed applications, wherein a lateral attack vector is an object of a first resource within the network that has a potential to be used by an attacker who discovered the first resource to further discover information regarding a second resource within the network, the second resource being previously undiscovered by the attacker, and wherein the decoy lateral attack vectors in the first group conform to the characteristics of the first group, and the decoy lateral attack vectors in the second group conform to the characteristics of the second group.
Shlomo Touboul; Hanan Levin; Stephane Roubach; Assaf Mischari; Itai Ben David; Itay Avraham; Adi Ozer; Chen Kazaz; Ofer Israeli; Olga Vingurt; Liad Gareh; Israel Grimberg; Cobby Cohen; Sharon Sultan; Matan Kubovsky
Automatically generating network resource groups and assigning customized decoy policies thereto
Reference - Broadcast isolation and level 3 network switch - Hewlett Packard Enterprise Development LP
A network switch comprising a switching Application Specific Integrated Circuit (ASIC) and a Virtual Switching Engine (VSE) connected to a plurality of ports. The switching ASIC has a high-speed memory table which enables it to look up addresses that it has previously obtained and to forward unicast packets to said addresses. The VSE is a CPU that makes switching decisions outside of the ASIC and keeps track of any unknown addresses, forwarding the packets out the appropriate ports and answers broadcast packets by proxy for all known addresses without forwarding any of the packets down the VLANs, thereby freeing the VLAN bandwidth from excessive traffic. The system requires no user configuration because the switching methodology is self-adaptive to the network in which it is inserted and has the ability to perform router functions such as level 2 and 3 switching, spanning tree protocols and compatibility with Internetwork Packet and Internetwork Packet Exchange networks.
Hewlett Packard Enterprise Development LP
Broadcast isolation and level 3 network switch
Reference - CAR-2014-05-001: RPC Activity - MITRE
Microsoft Windows uses its implementation of Distributed Computing Environment/Remote Procedure Call (DCE/RPC), which it calls Microsoft RPC, to call certain APIs remotely. A Remote Procedure Call is initiated by communicating to the RPC Endpoint Mapper, which exists as the Windows service RpcEptMapper and listens on the port 135/tcp. The endpoint mapper resolves a requested endpoint/interface and responds to the client with the port that the service is listening on. Since the RPC endpoints are assigned ports when the services start, these ports are dynamically assigned from 49152 to 65535. The connection to the endpoint mapper then terminates and the client program can communicate directly with the requested service. RPC is a legitimate functionality of Windows that allows remote interaction with a variety of services. For a Windows environment to be properly configured, several programs use RPC to communicate legitimately with servers. The background and benign RPC activity may be enormous, but must be learned, especially peer-to-peer RPC between workstations, which is often indicative of Lateral Movement.
Reference - CAR-2014-11-007: Remote Windows Management Instrumentation (WMI) over RPC - MITRE
As described in ATT&CK, an adversary can use Windows Management Instrumentation (WMI) to view or manipulate objects on a remote host. It can be used to remotely edit configuration, start services, query files, and anything that can be done with a WMI class. When remote WMI requests are over RPC (CAR-2014-05-001), it connects to a DCOM interface within the RPC group netsvcs. To detect this activity, a sensor is needed at the network level that can decode RPC traffic or on the host where the communication can be detected more natively, such as Event Tracing for Windows. Using wireshark/tshark decoders, the WMI interfaces can be extracted so that WMI activity over RPC can be detected. Although the description details how to detect remote WMI precisely, a decent estimate has been to look for the string RPCSS within the initial RPC connection on 135/tcp. It returns a superset of this activity, and will trigger on all DCOM-related services running within RPC, which is likely to also be activity that should be detected between hosts. More about RPCSS at : rpcss_dcom_interfaces.html
CAR-2014-11-007: Remote Windows Management Instrumentation (WMI) over RPC
Reference - CAR-2015-04-001: Remotely Scheduled Tasks via AT - MITRE
When AT.exe is used to remotely schedule tasks, Windows uses named pipes over SMB to communicate with the API on the remote machine. After authentication over SMB, the Named Pipe “ATSVC” is opened, over which the JobAdd function is called. On the remote host, the job files are created by the Task Scheduler and follow the convention C:\Windows\System32\AT<job\_id>. Unlike CAR-2013-05-004, this analytic specifically focuses on uses of AT that can be detected between hosts, indicating remotely gained execution. This pipe activity could be discovered with a network decoder, such as that in wireshark, that can inspect SMB traffic to identify the use of pipes. It could also be detected by looking for raw packet capture streams or from a custom sensor on the host that hooks the appropriate API functions. If no network or API level of visibility is possible, this traffic may inferred by looking at SMB connections over 445/tcp followed by the creation of files matching the pattern C:\Windows\System32\AT\<job_id\>.
CAR-2015-04-001: Remotely Scheduled Tasks via AT
Reference - CAR-2016-04-004: Successful Local Account Login
Reference - CAR-2020-04-001: Shadow Copy Deletion - MITRE
The Windows Volume Shadow Copy Service is a built-in OS feature that can be used to create backup copies of files and volumes. Adversaries may delete these shadow copies, typically through the usage of system utilities such as vssadmin.exe or wmic.exe, in order prevent file and data recovery. This technique is commonly employed for this purpose by ransomware.
Reference - CAR-2020-05-001: MiniDump of LSASS - MITRE
This analytic detects the minidump variant of credential dumping where a process opens lsass.exe in order to extract credentials using the Win32 API call MiniDumpWriteDump. Tools like SafetyKatz, SafetyDump, and Outflank-Dumpert default to this variant and may be detected by this analytic, though keep in mind that not all options for using those tools will result in this specific behavior. The analytic is based on a Sigma analytic contributed by Samir Bousseaden and written up in a blog on MENASEC. It looks for a call trace that includes either dbghelp.dll or dbgcore.dll, which export the relevant functions/permissions to perform the dump. It also detects using the Windows Task Manager (taskmgr.exe) to dump lsass, which is described in CAR-2019-08-001. In this iteration of the Sigma analytic, the GrantedAccess filter isn’t included because it didn’t seem to filter out any false positives and introduces the potential for evasion. This analytic was tested both in a lab and in a production environment with a very low false-positive rate. werfault.exe and tasklist.exe, both standard Windows processes, showed up multiple times as false positives.
Reference - CAR-2020-05-003: Rare LolBAS Command Lines - MITRE
LoLBAS are binaries and scripts that are built in to Windows, frequently are signed by Microsoft, and may be used by an attacker. Some LoLBAS are used very rarely and it might be possible to alert every time they’re used (this would depend on your environment), but many others are very common and can’t be simply alerted on. This analytic takes all instances of LoLBAS execution and then looks for instances of command lines that are not normal in the environment. This can detect attackers (which will tend to need the binaries for something different than normal usage) but will also tend to have false positives. The analytic needs to be tuned. The 1.5 in the query is the number of standard deviations away to look. It can be tuned up to filter out more noise and tuned down to get more results. This means it is probably best as a hunting analytic when you have analysts looking at the screen and able to tune the analytic up and down, because the threshold may not be stable for very long.
CAR-2020-05-003: Rare LolBAS Command Lines
Reference - CAR-2020-08-001: NTFS Alternate Data Stream Execution - System Utilities - MITRE
NTFS Alternate Data Streams (ADSs) may be used by adversaries as a means of evading security tools by storing malicious data or binaries in file attribute metadata. ADSs are also powerful because they can be directly executed by various Windows tools; accordingly, this analytic looks at common ways of executing ADSs using system utilities such as powershell.
CAR-2020-08-001: NTFS Alternate Data Stream Execution - System Utilities
Reference - CAR-2020-09-001: Scheduled Task - FileAccess - MITRE
In order to gain persistence, privilege escalation, or remote execution, an adversary may use the Windows Task Scheduler to schedule a command to be run at a specified time, date, and even host. Task Scheduler stores tasks as files in two locations - C:\Windows\Tasks (legacy) or C:\Windows\System32\Tasks. Accordingly, this analytic looks for the creation of task files in these two locations.
CAR-2020-09-001: Scheduled Task - FileAccess
Reference - CAR-2020-09-002: Component Object Model Hijacking - MITRE
Adversaries may establish persistence or escalate privileges by executing malicious content triggered by hijacked references to Component Object Model (COM) objects. This is typically done by replacing COM object registry entries under the HKEY_CURRENT_USER\Software\Classes\CLSID or HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID keys. Accordingly, this analytic looks for any changes under these keys.
CAR-2020-09-002: Component Object Model Hijacking
Reference - CAR-2020-09-003: Indicator Blocking - Driver Unloaded - MITRE
Adversaries may attempt to evade system defenses by unloading minifilter drivers used by host-based sensors such as Sysmon through the use of the fltmc command-line utility. Accordingly, this analytic looks for command-line invocations of this utility when used to unload minifilter drivers.
CAR-2020-09-003: Indicator Blocking - Driver Unloaded
Reference - CAR-2020-09-004: Credentials in Files & Registry - MITRE
Adversaries may search the Windows Registry on compromised systems for insecurely stored credentials for credential access. This can be accomplished using the query functionality of the reg.exe system utility, by looking for keys and values that contain strings such as “password”. In addition, adversaries may use toolkits such as PowerSploit in order to dump credentials from various applications such as IIS.Accordingly, this analytic looks for invocations of reg.exe in this capacity as well as that of several powersploit modules with similar functionality.
CAR-2020-09-004: Credentials in Files & Registry
Reference - CAR-2020-09-005: AppInit DLLs - MITRE
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. These values can be abused to obtain elevated privileges by causing a malicious DLL to be loaded and run in the context of separate processes. Accordingly, this analytic looks for modifications to these registry keys that may be indicative of this type of abuse.
Reference - CAR-2020-11-002: Local Network Sniffing - MITRE
Adversaries may use a variety of tools to gain visibility on the current status of things on the network: which processes are listening on which ports, which services are running on other hosts, etc. This analytic looks for the names of the most common network sniffing tools. While this may be noisy on networks where sysadmins are using any of these tools on a regular basis, in most networks their use is noteworthy.
Reference - CAR-2020-11-003: DLL Injection with Mavinject - MITRE
Injecting a malicious DLL into a process is a common adversary TTP. Although the ways of doing this are numerous, mavinject.exe is a commonly used tool for doing so because it roles up many of the necessary steps into one, and is available within Windows. Attackers may rename the executable, so we also use the common argument “INJECTRUNNING” as a related signature here. Whitelisting certain applications may be necessary to reduce noise for this analytic.
CAR-2020-11-003: DLL Injection with Mavinject
Reference - CAR-2020-11-004: Processes Started From Irregular Parent - MITRE
Adversaries may start legitimate processes and then use their memory space to run malicious code. This analytic looks for common Windows processes that have been abused this way in the past; when the processes are started for this purpose they may not have the standard parent that we would expect. This list is not exhaustive, and it is possible for cyber actors to avoid this discepency. These signatures only work if Sysmon reports the parent process, which may not always be the case if the parent dies before sysmon processes the event.
CAR-2020-11-004: Processes Started From Irregular Parent
Reference - CAR-2020-11-005: Clear Powershell Console Command History - MITRE
Adversaries may attempt to conceal their tracks by deleting the history of commands run within the Powershell console, or turning off history saving to begin with. This analytic looks for several commands that would do this. This does not capture the event if it is done within the console itself; only commandline-based commands are detected. Note that the command to remove the history file directly may very a bit if the history file is not saved in the default path on a particular system.
CAR-2020-11-005: Clear Powershell Console Command History
Reference - CAR-2020-11-006: Local Permission Group Discovery - MITRE
Cyber actors frequently enumerate local or domain permissions groups. The net utility is usually used for this purpose. This analytic looks for any instances of net.exe, which is not normally used for benign purposes, although system administrator actions may trigger false positives.
CAR-2020-11-006: Local Permission Group Discovery
Reference - CAR-2020-11-007: Network Share Connection Removal - MITRE
Adversaries may use network shares to exfliltrate date; they will then remove the shares to cover their tracks. This analytic looks for the removal of network shares via commandline, which is otherwise a rare event.
CAR-2020-11-007: Network Share Connection Removal
Reference - CAR-2020-11-008: MSBuild and msxsl - MITRE
Trusted developer utilities such as MSBuild may be leveraged to run malicious code with elevated privileges. This analytic looks for any instances of msbuild.exe, which will execute any C# code placed within a given XML document; and msxsl.exe, which processes xsl transformation specifications for XML files and will execute a variaty of scripting languages contained within the XSL file. Both of these executables are rarely used outside of Visual Studio.
Reference - CAR-2020-11-009: Compiled HTML Access - MITRE
Adversaries may hide malicious code in .chm compiled HTML files. When these files are read, Windows uses the HTML help executable named hh.exe, which is the signature for this analytic.
Reference - CAR-2020-11-011: Registry Edit from Screensaver
Adversaries may use screensaver files to run malicious code. This analytic triggers on suspicious edits to the screensaver registry keys, which dictate which .scr file the screensaver runs.
CAR-2020-11-011: Registry Edit from Screensaver
Reference - CAR-2021-01-002: Unusually Long Command Line Strings - MITRE
Often, after a threat actor gains access to a system, they will attempt to run some kind of malware to further infect the victim machine. These malware often have long command line strings, which could be a possible indicator of attack. Here, we use sysmon and Splunk to first find the average command string length and search for command strings that stretch over multiple lines, thus identifying anomalies and possibly malicious commands.
CAR-2021-01-002: Unusually Long Command Line Strings
Reference - CAR-2021-01-003: Clearing Windows Logs with Wevtutil - MITRE
In an attempt to clear traces after compromising a machine, threat actors often try to clear Windows Event logs. This is often done using “wevtutil”, a legitimate tool provided by Microsoft. This action interferes with event collection and notification, and may lead to a security event going undetected, thereby potentially leading to further compromise of the network.
CAR-2021-01-003: Clearing Windows Logs with Wevtutil
Reference - CAR-2021-01-004: Unusual Child Process for Spoolsv.Exe or Connhost.Exe - MITRE
After gaining initial access to a system, threat actors attempt to escalate privileges as they may be operating within a lower privileged process which does not allow them to access protected information or carry out tasks which require higher permissions. A common way of escalating privileges in a system is by externally invoking and exploiting spoolsv or connhost executables, both of which are legitimate Windows applications. This query searches for an invocation of either of these executables by a user, thus alerting us of any potentially malicious activity.
CAR-2021-01-004: Unusual Child Process for Spoolsv.Exe or Connhost.Exe
Reference - CAR-2021-01-006: Unusual Child Process spawned using DDE exploit - MITRE
CAR-2021-01-006: Unusual Child Process spawned using DDE exploit
Reference - CAR-2021-01-007: Detecting Tampering of Windows Defender Command Prompt - MITRE
In an attempt to avoid detection after compromising a machine, threat actors often try to disable Windows Defender. This is often done using “sc” [service control], a legitimate tool provided by Microsoft for managing services. This action interferes with event detection and may lead to a security event going undetected, thereby potentially leading to further compromise of the network.
CAR-2021-01-007: Detecting Tampering of Windows Defender Command Prompt
Reference - CAR-2021-01-008: Disable UAC - MITRE
Threat actors often, after compromising a machine, try to disable User Access Control (UAC) to escalate privileges. This is often done by changing the registry key for system policies using “reg.exe”, a legitimate tool provided by Microsoft for modifying the registry via command prompt or scripts. This action interferes with UAC and may enable a threat actor to escalate privileges on the compromised system, thereby allowing further exploitation of the system.
Reference - CAR-2021-01-009: Detecting Shadow Copy Deletion via Vssadmin.exe - MITRE
After compromising a network of systems, threat actors often try to delete Shadow Copy in an attempt to prevent administrators from restoring the systems to versions present before the attack. This is often done via vssadmin, a legitimate Windows tool to interact with shadow copies. This non-detection of this technique, which is often employed by ransomware strains such as “Olympic Destroyer”, may lead to a failure in recovering systems after an attack.
CAR-2021-01-009: Detecting Shadow Copy Deletion via Vssadmin.exe
Reference - CAR-2021-02-001: Webshell-Indicative Process Tree - MITRE
A web shell is a web script placed on an openly accessible web server to allow an adversary to use the server as a gatway in a network. As the shell operates, commands will be issued from within the web application into the broader server operating system. This analytic looks for host enumeration executables initiated by any web service that would not normally be executed within that environment.
CAR-2021-02-001: Webshell-Indicative Process Tree
Reference - CAR-2021-02-002: Get System Elevation - MITRE
Cyber actors frequently escalate to the SYSTEM account after gaining entry to a Windows host, to enable them to carry out various attacks more effectively. Tools such as Meterpreter, Cobalt Strike, and Empire carry out automated steps to “Get System”, which is the same as switching over to the System user account. Most of these tools utilize multiple techniques to try and attain SYSTEM: in the first technique, they create a named pipe and connects an instance of cmd.exe to it, which allows them to impersonate the security context of cmd.exe, which is SYSTEM. In the second technique, a malicious DLL is injected into a process that is running as SYSTEM; the injected DLL steals the SYSTEM token and applies it where necessary to escalate privileges. This analytic looks for both of these techniques.
Reference - CAR-2021-04-001: Common Windows Process Masquerading - MITRE
Masquerading (T1036) is defined by ATT&CK as follows: “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.” Malware authors often use this technique to hide malicious executables behind legitimate Windows executable names (e.g. lsass.exe, svchost.exe, etc). There are several sub-techniques, but this analytic focuses on Match Legitimate Name or Location only.
CAR-2021-04-001: Common Windows Process Masquerading
Reference - CAR-2021-05-001: Attempt To Add Certificate To Untrusted Store - MITRE
Adversaries may add their own root certificate to the certificate store, to cause the web browser to trust that certificate and not display a security warning when it encounters the previously unseen certificate. This action may be the precursor to malicious activity.
CAR-2021-05-001: Attempt To Add Certificate To Untrusted Store
Reference - CAR-2021-05-002: Batch File Write to System32 - MITRE
While batch files are not inherently malicious, it is uncommon to see them created after OS installation, especially in the Windows directory. This analytic looks for the suspicious activity of a batch file being created within the C:\Windows\System32 directory tree. There will be only occasional false positives due to administrator actions.
CAR-2021-05-002: Batch File Write to System32
Reference - CAR-2021-05-004: BITS Job Persistence - MITRE
The following query identifies Microsoft Background Intelligent Transfer Service utility bitsadmin.exe scheduling a BITS job to persist on an endpoint. The query identifies the parameters used to create, resume or add a file to a BITS job. Typically seen combined in a oneliner or ran in sequence. If identified, review the BITS job created and capture any files written to disk. It is possible for BITS to be used to upload files and this may require further network data analysis to identify. You can use bitsadmin /list /verbose to list out the jobs during investigation.
Reference - CAR-2021-05-005: BITSAdmin Download File - MITRE
The following query identifies Microsoft Background Intelligent Transfer Service utility bitsadmin.exe using the transfer parameter to download a remote object. In addition, look for download or upload on the command-line, the switches are not required to perform a transfer. Capture any files downloaded. Review the reputation of the IP or domain used. Typically once executed, a follow on command will be used to execute the dropped file. Note that the network connection or file modification events related will not spawn or create from bitsadmin.exe, but the artifacts will appear in a parallel process of svchost.exe with a command-line similar to svchost.exe -k netsvcs -s BITS. It’s important to review all parallel and child processes to capture any behaviors and artifacts. In some suspicious and malicious instances, BITS jobs will be created. You can use bitsadmin /list /verbose to list out the jobs during investigation.
CAR-2021-05-005: BITSAdmin Download File
Reference - CAR-2021-05-006: CertUtil Download With URLCache and Split Arguments - MITRE
Certutil.exe may download a file from a remote destination using -urlcache. This behavior does require a URL to be passed on the command-line. In addition, -f (force) and -split (Split embedded ASN.1 elements, and save to files) will be used. It is not entirely common for certutil.exe to contact public IP space. However, it is uncommon for certutil.exe to write files to world writeable paths.\ During triage, capture any files on disk and review. Review the reputation of the remote IP or domain in question.
CAR-2021-05-006: CertUtil Download With URLCache and Split Arguments
Reference - CAR-2021-05-007: CertUtil Download With VerifyCtl and Split Arguments - MITRE
Certutil.exe may download a file from a remote destination using -VerifyCtl. This behavior does require a URL to be passed on the command-line. In addition, -f (force) and -split (Split embedded ASN.1 elements, and save to files) will be used. It is not entirely common for certutil.exe to contact public IP space. \ During triage, capture any files on disk and review. Review the reputation of the remote IP or domain in question. Using -VerifyCtl, the file will either be written to the current working directory or %APPDATA%\..\LocalLow\Microsoft\CryptnetUrlCache\Content\<hash>.
CAR-2021-05-007: CertUtil Download With VerifyCtl and Split Arguments
Reference - CAR-2021-05-008: Certutil exe certificate extraction - MITRE
This search looks for arguments to certutil.exe indicating the manipulation or extraction of Certificate. This certificate can then be used to sign new authentication tokens specially inside Federated environments such as Windows ADFS.
CAR-2021-05-008: Certutil exe certificate extraction
Reference - CAR-2021-05-009: CertUtil With Decode Argument - MITRE
CertUtil.exe may be used to encode and decode a file, including PE and script code. Encoding will convert a file to base64 with -----BEGIN CERTIFICATE----- and -----END CERTIFICATE----- tags. Malicious usage will include decoding a encoded file that was downloaded. Once decoded, it will be loaded by a parallel process. Note that there are two additional command switches that may be used - encodehex and decodehex. Similarly, the file will be encoded in HEX and later decoded for further execution. During triage, identify the source of the file being decoded. Review its contents or execution behavior for further analysis.
CAR-2021-05-009: CertUtil With Decode Argument
Reference - CAR-2021-05-010: Create local admin accounts using net exe - MITRE
This search looks for the creation of local administrator accounts using net.exe.
CAR-2021-05-010: Create local admin accounts using net exe
Reference - CAR-2021-05-011: Create Remote Thread into LSASS - MITRE
Actors may create a remote thread into the LSASS service as part of a workflow to dump credentials.
CAR-2021-05-011: Create Remote Thread into LSASS
Reference - Certificate and Public Key Pinning
Certificate and Public Key Pinning technical guide to implementing certificate and public key pinning.
Google's Certificate Transparency project fixes several structural flaws in the SSL certificate system, which is the main cryptographic system that underlies all HTTPS connections. These flaws weaken the reliability and effectiveness of encrypted Internet connections and can compromise critical TLS/SSL mechanisms, including domain validation, end-to-end encryption, and the chains of trust set up by certificate authorities.
Reference - Cisco ASR 9000 Series Aggregation Services Routers - Access List Commands
An access control list (ACL) consists of one or more access control entries (ACEs) that collectively define the network traffic profile. This profile can then be referenced by Cisco IOS XR Software software features such as traffic filtering, priority or custom queueing, and dynamic access control. Each ACL includes an action element (permit or deny) and a filter element based on criteria such as source address, destination address, protocol, and protocol-specific parameters.
Cisco ASR 9000 Series Aggregation Services Routers - Access List Commands
Reference - CAR-2014-11-008: Command Launched from WinLogon - MITRE
An adversary can use accessibility features (Ease of Access), such as StickyKeys or Utilman, to launch a command shell from the logon screen and gain SYSTEM access. Since an adversary does not have physical access to the machine, this technique must be run within Remote Desktop. To prevent an adversary from getting to the login screen without first authenticating, Network-Level Authentication (NLA) must be enabled. If a debugger is set up for one of the accessibility features, then it will intercept the process launch of the feature and instead execute a new command line. This analytic looks for instances of cmd.exe or powershell.exe launched directly from the logon process, winlogon.exe. It should be used in tandem with CAR-2014-11-003, which detects the accessibility programs in the command line.
CAR-2014-11-008: Command Launched from WinLogon
Reference - CAR-2013-07-005: Command Line Usage of Archiving Software - MITRE
Before exfiltrating data that an adversary has collected, it is very likely that a compressed archive will be created, so that transfer times are minimized and fewer files are transmitted. There is variety between the tools used to compress data, but the command line usage and context of archiving tools, such as ZIP, RAR, and 7ZIP, should be monitored. In addition to looking for RAR or 7z program names, command line usage of 7Zip or RAR can be detected with the flag usage of "\* a \*". This is helpful, as adversaries may change program names.
CAR-2013-07-005: Command Line Usage of Archiving Software
Reference - Computational modeling and classification of data streams - Crowdstrike Inc
Example techniques described herein determine a signature or classification of a data stream such as a file. The classification can indicate whether the data stream is associated with malware. A processor can locate training analysis regions of training data streams based on predetermined structure data, and determining training model inputs based on the training analysis regions. The processor can determine a computational model based on the training model inputs. The computational model can receive an input vector and provide a corresponding feature vector. The processor can then locate a trial analysis region of a trial data stream based on the predetermined structure data and determine a trial model input. The processor can operate the computational model based on the trial model input to provide a trial feature vector, e.g., a signature. The processor can operate a second computational model to provide a classification based on the signature.
Sven Krasser; David Elkind; Patrick Crenshaw; Brett Meyer
Provides a mechanism to classify files using file signatures based on a computational model. Training data that comprises at least a portion of a file, e.g. number of bytes, is used as input to the computational model to develop a file signature and classify the file as malware.
Computational modeling and classification of data streams
Reference - Computer-implemented methods and systems for identifying visually similar text character strings - Greathorn Inc
Methods and systems are disclosed for selecting text character strings from a corpus of relevant strings that would commonly be considered to be visually similar to human viewer to an input string. The initial corpus may be any sufficiently broad or specific source of text, e.g., the names of users in a computer application system. The character strings in the corpus are classified such that direct, character-by-character comparisons may be limited to a small subset of likely-similar strings. The input string is then directly compared to strings that are likely to be similar to it, taking into account individual characters' similarities, combinations of characters that look similar to individual characters, transposition of characters, and simple additions and deletions.
Text input is compared to an engine of look-alike sets of text characters. An estimate of similar characters based on the engine is conducted, and an alert is triggered if the estimated similarity is lower than a given threshold.
Computer-implemented methods and systems for identifying visually similar text character strings
Reference - Computer motherboard having peripheral security functions
A secure motherboard for a computer, wherein each user accessible peripheral port is protected by hardware based peripheral protection circuitry soldered to the motherboard.
Computer motherboard having peripheral security functions
Reference - Computer Worm Defense System and Method - FireEye Inc
"A computer worm defense system comprises multiple containment systems tied together by a management system. Each containment system is deployed on a separate communication network and contains a worm sensor and a blocking system. In various embodiments, the computer worm may be transported from a production network, where the computer worm is not readily identifiable, to an alternate network in the worm sensor where the computer worm may be readily identifiable. Computer worm identifiers generated by a worm sensor of one containment system can be provided not only to the blocking system of the same containment system, but can also be distributed by the management system to blocking systems of other containment systems."
This patent describes network data being copied by a tap and then analyzed in an analysis environment to determine whether the network data is suspicious using a heuristic module. The analysis environment replays transmission of the suspicious network data between a configured replayer and a virtual machine to detect unauthorized activity.
Reference - Computing apparatus with automatic integrity reference generation and maintenance - Tripwire, Inc.
An apparatus is equipped to automatically update one or more integrity references of a software entity, when the software entity is installed onto the apparatus. The apparatus is further equipped to periodically determine whether the integrity of the apparatus has been compromised based at least in part on the one or more integrity references of the software entity that are automatically updated during installation of the software entity.
Computing apparatus with automatic integrity reference generation and maintenance
Reference - Configure User Access Control and Permissions
When deployed on Windows Server, Windows Admin Center provides a centralized point of management for your server environment. By controlling access to Windows Admin Center, you can improve the security of your management landscape.
Configure User Access Control and Permissions
Container Images can contain unneeded, unsecured or insecure files. By analyzing the container image, we can identify whether it respects a specific set of predefined policies.
Reference - Content extractor and analysis system - Bit 9 Inc, Carbon Black Inc
A security system provides a defense from known and unknown viruses, worms, spyware, hackers, and unwanted software. The system can implement centralized policies that allow an administrator to approve, block, quarantine, and log file activities. The system can extract content of interest from a file container, repackage the content of interest as another valid file type, perform hashes on the content of interest, associate the hash of the container with the hash of the repackaged content, transfer the repackaged content, and store the hash with other security-related information.
Reference - Continuous authentication by analysis of keyboard typing characteristics - Bradford Univ., UK
This paper describes a simple, software based keyboard monitoring system for the IBM PC for the continuous analysis of the typing characteristics of the user for the purpose of continuous authentication. By exploiting the electrical characteristics of the PC keyboard interface together with modifications to the internal system timer, very accurate measurements can be made of keystroke interval and duration, including measurements of rollover. Rollover patterns, particularly when typing common diphthongs, can be highly characteristic of individual users and provide quite an accurate indication of the users identity. Published in: European Convention on Security and Detection, 1995.
Continuous authentication by analysis of keyboard typing characteristics
Reference - CAR-2019-04-004: Credential Dumping via Mimikatz - MITRE
Credential dumpers like Mimikatz can be loaded into memory and from there read data from another processes. This analytic looks for instances where processes are requesting specific permissions to read parts of the LSASS process in order to detect when credential dumping is occurring. One weakness is that all current implementations are "overtuned" to look for common access patterns used by Mimikatz.
CAR-2019-04-004: Credential Dumping via Mimikatz
Reference - CAR-2019-08-001: Credential Dumping via Windows Task Manager - MITRE
The Windows Task Manager may be used to dump the memory space of lsass.exe to disk for processing with a credential access tool such as Mimikatz. This is performed by launching Task Manager as a privileged user, selecting lsass.exe, and clicking "Create dump file". This saves a dump file to disk with a deterministic name that includes the name of the process being dumped. This requires filesystem data to determine whether files have been created.
CAR-2019-08-001: Credential Dumping via Windows Task Manager
MITRE’s Cyber Command System (CyCS) tool addresses the objective of improved mission assurance in cyberspace by enabling the mapping of mission operations to the network operations that support those missions. This tool provides mission-impact assessment through situational awareness and impact analysis. CyCS addresses mission-assurance challenges for highly distributed enterprise systems of systems through vulnerability, threat, and consequence management.
Reference - Cyber vaccine and predictive-malware-defense methods and systems
Methods and systems for Predictive Malware Defense (PMD) are described. The systems and methods can utilize advanced machine-learning (ML) techniques to generate malware defenses preemptively. Embodiments of PMD can utilize models, which are trained on features extracted from malware families, to predict possible courses of malware evolution. PMD captures these predicted future evolutions in signatures of as yet unseen malware variants to function as a malware vaccine. These signatures of predicted future malware “evolutions” can be added to the training set of a machine-learning (ML) based malware detection and/or mitigation system so that it can detect these new variants as they arrive.
Michael Howard, Avi Pfeifer, Mukesh Dalal, Michael Reposa
Cyber vaccine and predictive-malware-defense methods and systems
Reference - CAR-2013-10-002: DLL Injection via Load Library - MITRE
Microsoft Windows allows for processes to remotely create threads within other processes of the same privilege level. This functionality is provided via the Windows API CreateRemoteThread. Both Windows and third-party software use this ability for legitimate purposes. For example, the Windows process csrss.exe creates threads in programs to send signals to registered callback routines. Both adversaries and host-based security software use this functionality to inject DLLs, but for very different purposes. An adversary is likely to inject into a program to evade defenses or bypass User Account Control, but a security program might do this to gain increased monitoring of API calls. One of the most common methods of DLL Injection is through the Windows API LoadLibrary. Allocate memory in the target program with VirtualAllocEx Write the name of the DLL to inject into this program with WriteProcessMemory Create a new thread and set its entry point to LoadLibrary using the API CreateRemoteThread. This behavior can be detected by looking for thread creations across processes, and resolving the entry point to determine the function name. If the function is LoadLibraryA or LoadLibraryW, then the intent of the remote thread is clearly to inject a DLL. When this is the case, the source process must be examined so that it can be ignored when it is both expected and a trusted process.
CAR-2013-10-002: DLL Injection via Load Library
Reference - DNS Whitelist (DNSWL) Email Authentication Method Extension
DNS Whitelist (DNSWL) Email Authentication Method Extension
Reference - /DYNAMICBASE (Use address space layout randomization) - Microsoft Docs
/DYNAMICBASE (Use address space layout randomization)
Dagger is a modeling and visualization tool suite that shows how system failures impact mission status. Updated with manual or real-time status, Dagger is used for mission/system planning, situational awareness during mission execution, and course-of-action analysis.
Reference - Dagger: Modeling and visualization for mission impact situational awareness
Dagger is a modeling and visualization framework that addresses the challenge of representing knowledge and information for decision-makers, enabling them to better comprehend the operational context of network security data. It allows users to answer critical questions such as “Given that I care about mission X, is there any reason I should be worried about what is going on in cyberspace?” or “If this system fails, will I still be able to accomplish my mission?”.
Dagger: Modeling and visualization for mission impact situational awareness
Reference - Mitigate threats by using Windows 10 security features: Data Execution Prevention - Microsoft
Malware depends on its ability to insert a malicious payload into memory with the hope that it will be executed later. Wouldn't it be great if you could prevent malware from running if it wrote to an area that has been allocated solely for the storage of information? Data Execution Prevention (DEP) does exactly that, by substantially reducing the range of memory that malicious code can use for its benefit. DEP uses the No eXecute bit on modern CPUs to mark blocks of memory as read-only so that those blocks can't be used to execute malicious code that may be inserted by means of a vulnerability exploit.
Nick Schonning, Daniel Simpson, Marty Hernandez Avedon, Trond B. Krokli, jreeds, jcaparas, Andres Mariano Gorzelany, Tina Burden, Thomas Raya, Justin Hall, justanotheranonymoususer, Liza Poggemeyer, Dani Halfin, imba-tjd (Authors for entire page)
Mitigate threats by using Windows 10 security features: Data Execution Prevention
Reference - Data processing and scanning systems for generating and populating a data inventory
In particular embodiments, a data processing data inventory generation system is configured to: (1) generate a data model (e.g., a data inventory) for one or more data assets utilized by a particular organization; (2) generate a respective data inventory for each of the one or more data assets; and (3) map one or more relationships between one or more aspects of the data inventory, the one or more data assets, etc. within the data model. In particular embodiments, a data asset (e.g., data system, software application, etc.) may include, for example, any entity that collects, processes, contains, and/or transfers personal data (e.g., such as a software application, “internet of things” computerized device, database, website, data-center, server, etc.). The system may be configured to identify particular data assets and/or personal data in data repositories using any suitable intelligent identity scanning technique.
Kabir A. Barday, Mihir S. Karanjkar, Steven W. Finch, Ken A. Browne, Nathan W. Heard, Aakash H. Patel, Jason L. Sabourin, Richard L. Daniel, Dylan D. Patton-Kuhl, Jonathan Blake Brannon
Data processing and scanning systems for generating and populating a data inventory
There is a significant body of work devoted to testing, verifying, and certifying the correctness of optimizing compilers. The focus of such work is to determine if source code and optimized code have the same functional semantics. In this paper, we introduce the correctness-security gap, which arises when a compiler optimization preserves the functionality of but violates a security guarantee made by source code. We show with concrete code examples that several standard optimizations, which have been formally proved correct, inhabit this correctness-security gap. We analyze this gap and conclude that it arises due to techniques that model the state of the program but not the state of the underlying machine. We propose a broad research program whose goal is to identify, understand, and mitigate the impact of security errors introduced by compiler optimizations. Our proposal includes research in testing, program analysis, theorem proving, and the development of new, accurate machine models for reasoning about the impact of compiler optimizations on security.
Google Inc, Purdue University, UC Berkeley
The Correctness-Security Gap in Compiler Optimization
Reference - CAR-2014-11-003: Debuggers for Accessibility Applications - MITRE
The Windows Registry location HKLM\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options allows for parameters to be set for applications during execution. One feature used by malicious actors is the "Debugger" option. When a key has this value enabled, a Debugging command line can be specified. Windows will launch the Debugging command line, and pass the original command line in as an argument. Adversaries can set a Debugger for Accessibility Applications. The analytic looks for the original command line as an argument to the Debugger. When the strings "sethc.exe", "utilman.exe", "osk.exe", "narrator.exe", and "Magnify.exe" are detected in the arguments, but not as the main executable, it is very likely that a Debugger is set. This analytic could depend on the possibility of the known strings used as arguments for other applications used in the day-to-day environment. Although the chance of the string "sethc.exe" being used as an argument for another application is unlikely, it still is a possibility.
CAR-2014-11-003: Debuggers for Accessibility Applications
Reference - Deception-Based Responses to Security Attacks - Crowdstrike Inc
Deception-based techniques for responding to security attacks are described herein. The techniques include transitioning a security attack to a monitored computing device posing as a computing device impacted by the security attack and enabling the adversary to obtain deceptive information from the monitored computing device. Also, the adversary may obtain a document configured to report identifying information of an entity opening the document, thereby identifying the adversary associated with the attack. Further, the techniques include determining that a domain specified in a domain name request is associated with malicious activity and responding to the request with a network address of a monitored computing device to cause the requesting process to communicate with the monitored computing device in place of an adversary server. Additionally, a service may monitor dormant domains names associated with malicious activity and, in response to a change, respond with an alert or a configuration update.
Adam S. Meyers; Dmitri Alperovitch; George Robert Kurtz; David F. Diehl; Sven Krasser
Deception-Based Responses to Security Attacks
Reference - Decoy and deceptive data object technology - Cymmetria, Inc.
A computer implemented method of detecting unauthorized access to a protected network by monitoring a dynamically updated deception environment, comprising launching, on one or more decoy endpoints, one or more decoy operating system (OS) managing one or more of a plurality of deception applications mapping a plurality of applications executed in a protected network, updating dynamically a usage indication for a plurality of deception data objects deployed in the protected network to emulate usage of the plurality of deception data objects for accessing the deception application(s) wherein the plurality of deception data objects are configured to trigger an interaction with the deception application(s) when used, detecting usage of data contained in the deception data object(s) by monitoring the interaction and identifying one or more potential unauthorized operations based on analysis of the detection. In order to convince the potential attacker that the deception environment is the real (valid) processing environment and/or part thereof, the campaign manager may construct the false identity according to the public information of the certain user that may typically be available to the potential attacker. By exposing the real (public) information of the certain user to the potential attacker, the false identity may seem consistent and legitimate to the potential attacker. For example, the campaign manager may create a false account, for example, a Facebook account of the certain user that includes the same public information that is publicly available to other Facebook users from the real (genuine) Facebook account of the certain user. The fake company account may include information specific to the role and/or job title of certain user within the company, for example, a programmer, an accountant, an IT person and/or the like.
Dean Sysman, Gadi Evron, Imri Goldberg, Itamar Sher, Shmuel Ur
Decoy and deceptive data object technology
Reference - Decoy Network-Based Service for Deceiving Attackers - Amazon Technologies
A decoy network-based service uses a decoy credential to lure an attacker to access the decoy network-based service, and monitors the attacker's activity with respect to the decoy network-based service to determine the attacker's motivation. In various examples, a decoy credential is published on an Internet-accessible site, and a system that provides a network-based service (e.g., a service provider network) subsequently receives an access request from a computing device that includes the decoy credential. Based on the decoy credential, the computing device may be provided access to a decoy network-based service, and application programming interface (API) calls made by the computing device may be routed through a decoy control plane. The data relating to the API calls may be stored and analyzed to determine a motivation of the attacker, which may be used in various downstream applications to improve security for customers of the network-based service.
Decoy network-based service for deceiving attackers
Reference - Decoy Personas for Safeguarding Online Identity Using Deception - MITRE
What if online scammers weren't sure whether the user account they are targeting is really yours, or whether the information they compiled about you is real? It's worth considering whether decoy online personas might help in the quest to safeguard our digital identities and data. I believe deception tactics, such as selective and careful use of honeypots, holds promise for defending enterprise IT resources. Some forms of deception could also protect individuals against online scammers and other attackers. This approach might not be quite practical today for most people, but in the future we might find it both necessary and achievable. Human attackers and malicious software pursue user accounts and data on-line through harvesting, phishing, password-guessing, software vulnerabilities, and various other means. How might we use decoys to confuse, misdirect, slow down and detect adversaries engaged in such activities? ... The wealth of personal details available on social networking sites allows attackers to target individuals using social engineering, secret question-guessing and other techniques. For some examples of such approaches, see The Use of Fake or Fraudulent LinkedIn Profiles and Data Mining Resumes for Computer Attack Reconnaissance. Setting up one or more fake social network profiles (e.g., on Facebook) that use the person's real name can help the individual deflect the attack or can act as an early warning of an impending attack. A decoy profile could purposefully expose some inaccurate information, while the person's real profile would be more carefully concealed using the site's privacy settings. Decoy profiles would be associated with spamtrap email addresses. Similarly, the person could expose decoy profiles on other sites, for instance those reveal shopping habits (e.g., Amazon), musings (e.g., Twitter), skills (e.g., GitHub), travel (e.g., TripIt), affections (e.g., Pinterest), music taste (e.g., Pandora) and so on. The person's decoy identities could also have fake resumes available on sites such as Indeed and Monster.com.
Decoy Personas for Safeguarding Online Identity Using Deception
Reference - Detecting DDoS Attack Using Snort
A DDoS (Distributed Denial-of-Service) attack is very common and easy toexecute and does not require any sophisticated tools. It can happen to anyone. In this project we deploy snort in our home network as a NIDS (Network Intrusion Detection System) to detect a DDoS attack and prevent it.
Indian Institute of Information Technology Allahabad
Reference - Detecting network reconnaissance by tracking intranet dark-net communications - VECTRA NETWORKS Inc
A method and system for detecting network reconnaissance is disclosed wherein network traffic can be parsed into unidirectional flows that correspond to sessions. A learning module may categorize computing entities inside the network into assets and generate asset data to monitor the computing entities. If one or more computing entities address a flow to an address of a host that no longer exists, ghost asset data may be recorded and updated in the asset data. When a computing entity inside the network contacts an object in the dark-net, the computing entity may be recorded a potential mapper. When the computing entity tries to contact a number of objects in the dark-net, such that a computed threshold is exceeded, the computing entity is identified a malicious entity performing network reconnaissance.
This patent describes detecting an attacker performing internal reconnaissance within an organization's network to gather intelligence about the configuration of the network or identify the next target. Network packets are collected (ex. tapped from a network switch) and processed to create flows that are used to map out the network to identify network assets as well as ghost assets (addresses not assigned to a device or an existing device that is temporarily disabled). Once this mapping is complete it is used to monitor the network to determine if an attacker is attempting to connect to a ghost asset. If an attacker attempts to connect to a ghost asset over a threshold (ex. contacting four ghost assets in less than seven minutes), an alert is generated.
Detecting network reconnaissance by tracking intranet dark-net communications
Reference - Detection of Malicious IDNHomoglyph Domains
At early stages of Internet development, users were only able to register or access domains with ASCII characters. The introduction of IDN (Internationalized Domain Name) which uses the larger Unicode character set, made it possible for regional users to deal with domain names using their local language alphabet. Beside the advantages provided by IDN, a new type of network threats has also emerged. The reason behind this is that there are many similar-looking characters in Unicode system, called homoglyphs. These characters could be used by an attacker to lure users by replacing one or more characters of a benign domain.
Detection of Malicious IDN Homoglyph Domains Using Active DNS Measurements
Reference - Deterministic method for detecting and blocking of exploits on interpreted code - K2 Cyber Security Inc
In one aspect, a method useful for preventing exploitation of a vulnerability in an interpreted code by monitoring and validating an execution of the interpreted code in a script file by an application server, includes the step of generating a mapping for an incoming network connection to a specified script file to be executed by an application server. The computerized method includes the step of inserting a hook for monitoring an application programming interface (API) call or a privileged instruction executed by the application server. The computerized method includes the step of inserting a validation code configured to validate the API call or the privileged instruction executed by the interpreted code in a script.
This patent describes a technique for monitoring API calls. During execution of interpreted code the observed API calls are validated against a whitelist of API calls for that interpreted code file. Action is taken if the observed API call is not in accordance with the list.
Deterministic method for detecting and blocking of exploits on interpreted code
Reference - Digital Identity Guidelines 800-63-3
Reference - Distributed meta-information query in a network - Bit 9 Inc
A security system provides a defense from known and unknown viruses, worms, spyware, hackers, and social engineering attacks. The system can implement centralized policies that allow an administrator to approve, block, quarantine, and log file activities. A server associated with a number of hosts can provide a query for host computers to access security-related meta-information in local host stores. The query is pulled from the server by the hosts. The results of the distributed host query are stored and merged on the server, and exported for display, reports, or security response.
Provides a mechanism to detect, monitor, locate, and control files installed on host computers. Each host has a host agent that analyzes file system activity and takes action based on policies configured on a server. The policies identify whether to block, log, allow, or quarantine actions such as file accesses and execution of executables. Examples of policies include: * Block/log execution of new executables and detached scripts (e.g., .exe or .bat) * Block/log reading/execution of new embedded content (e.g., macros in .doc) * Block/log installation/modification of Web content (alteration of content in .html or .cgi files) * Block/log execution of new files in an administratively defined 'class'; e.g., an administrator might want to block screen savers .scr, but not the entire class of executables .exe, .dll, .sys, etc . . .
Distributed meta-information query in a network
Reference - Domain age registration alert - Inc Rapid7 Inc RAPID7 Inc
Systems and methods of identifying a security risk by monitoring and generating alerts based on attempts to access web domains that have been registered within a short period of time and are therefore identified as "high-risk," including identifying an attempt to access a domain; receiving a registration date of the domain; and detecting a security risk based on the registration date of the domain.
Reference - End-to-end certificate pinning
Some embodiments implement end-to-end certificate pinning for content intake from various content providers and for content distribution to various end users. To ensure secure retrieval of content provider content, the content distributor pins the content provider to one or more certificate authorities.
Tin Zaw, Reed Morrison, Robert J. Peters
Reference - Enhancing Network Security By Preventing User-Initiated Malware Execution - MITRE
In this paper, we describe characteristics of the most widely used defense techniques for the blocking of user-initiated malware and why these techniques are insufficient. We then introduce a module verification strategy that will eliminate, or at least severely reduce, this problem by extending the classic "defense in depth" network security strategy. We then describe how the augmentation of a standard operating system loader to include references to a database of cryptographic hashes of module executables can be used to implement this strategy. Finally, we describe our efforts towards the creation of a prototype system that implements the module verification strategy.
This paper describes application whitelisting. New software executable code is compared to a database of allowed software to determine if the new executable code should be loaded and executed. A database of cryptographic hashes is first created for all allowed software executables. Prior to loading any new executable code, a hash is computed and compared against the hash database. If the hash for the new code does not appear in the database, the executable is not loaded and executed.
Enhancing Network Security By Preventing User-Initiated Malware Execution
Reference - Eviction Guidance for Networks Affected by the SolarWinds and Active Directory/M365 Compromise - CISA
Eviction Guidance for Networks Affected by the SolarWinds and Active Directory/M365 Compromise
Reference - CAR-2013-05-004: Execution with AT - MITRE
In order to gain persistence, privilege escalation, or remote execution, an adversary may use the Windows built-in command AT (at.exe) to schedule a command to be run at a specified time, date, and even host. This method has been used by adversaries and administrators alike. Its use may lead to detection of compromised hosts and compromised users if it is used to move laterally. The built-in Windows tool schtasks.exe (CAR-2013-08-001) offers greater flexibility when creating, modifying, and enumerating tasks. For these reasons, schtasks.exe is more commonly used by administrators, tools/scripts, and power users.
Reference - CAR-2013-08-001: Execution with schtasks - MITRE
The Windows built-in tool schtasks.exe provides the creation, modification, and running of scheduled tasks on a local or remote computer. It is provided as a more flexible alternative to at.exe, described in CAR-2013-05-004. Although used by adversaries, the tool is also legitimately used by administrators, scripts, and software configurations. The scheduled tasks tool can be used to gain Persistence and can be used in combination with a Lateral Movement technique to remotely gain execution. Additionally, the command has parameters to specify the user and password responsible for creating the task, as well as the user and password combination that the task will run as. The /s flag will cause a task to run as the SYSTEM user, usually indicating privilege escalation.
CAR-2013-08-001: Execution with schtasks
Reference - File-modifying malware detection - Crowdstrike Inc
A security agent implemented on a computing device is described herein. The security agent is configured to detect file-modifying malware by detecting that a process is traversing a directory of the memory of the computing device and detecting that the process is accessing files in the memory according to specified file access patterns. The security agent can also be configured to correlate actions of multiple processes that correspond to a specified file access pattern and detect that one or more of the multiple processes are malware by correlating their behavior.
This patent describes a technique for detecting file modifying malware such as wipers and ransomware that overwrite portions of files and encrypt portions of a computer's memory, respectively. Processes that are traversing a directory are identified along with file access patterns. Processes executing on a computing device that are traversing a directory include: * changing a directory of a process (e.g., iteratively, systematically, repeatedly) * detecting that a process is conducting an "open directory" operation repeatedly * the same process traversing through a directory and recording the locations of data files encountered in each sub - directory In addition to identifying processes traversing a directory, particular file access patterns are also detected that may be indicative of malicious behavior including: * multiple file types being accessed * accessing a large number of files * files located in multiple locations in the directory being accessed If a process is conducting a traversal of the directory and accessing files according to a defined access pattern associated with malicious behavior, a preventative action is performed.
Reference - File Integrity Monitoring in Microsoft Defender for Cloud - Microsoft
File Integrity Monitoring in Microsoft Defender for Cloud
Reference - Firmware Behavior Analysis ConFirm
The modernization of various critical infrastructure components has dictated the use of microprocessor-based embedded control systems in critical applications. It is often infeasible, however, to employ the same level of security measures used in general purpose computing systems, due to the stringent performance and resource constraints of embedded devices. Furthermore, as software relies on the firmware for proper operation, no software-level technique can detect malicious behavior of the firmware. In this work, we propose ConFirm, a low-cost technique to detect malicious modifications in the firmware of embedded systems by measuring the number of low-level hardware events that occur during the execution of the firmware.
Xueyang Wang, Charalambos Konstantinou, Michail Maniatakos, Ramesh Karri
Department of Electrical and Computer Engineering, Polytechnic School of Engineering, New York University and Department of Electrical and Computer Engineering, New York University Abu Dhabi
ConFirm: Detecting Firmware Modifications in Embedded Systems using Hardware Performance Counters
Reference - Firmware Behavior Analysis VIPER
Recent research demonstrates that malware can infect peripherals' firmware in a typical x86 computer system, e.g., by exploiting vulnerabilities in the firmware itself or in the firmware update tools. Verifying the integrity of peripherals' firmware is thus an important challenge. We propose software-only attestation protocols to verify the integrity of peripherals' firmware, and show that they can detect all known software-based attacks.
Yanlin Li, Jonathan M. McCune, Adrian Perrig
VIPER: Verifying the Integrity of PERipherals' Firmware
Reference - Firmware Embedded Monitoring Code Red Balloon
Systems and methods for securing embedded devices via both online and offline defensive strategies. One or more security software components may be injected into firmware binary to create a modified firmware binary, which is functionally- and size-equivalent to the original firmware binary. The security software components may retrieve live forensic information related to embedded devices for use in live hardening of the modified firmware binary while the embedded device is online, dynamically patching the firmware
Method and apparatus for securing embedded device firmware
Reference - Firmware Embedded Monitoring Code Symbiotes
A large number of embedded devices on the internet, such as routers and VOIP phones, are typically ripe for exploitation. Little to no defensive technology, such as AV scanners or IDS's, are available to protect these devices. We propose a host-based defense mechanism, which we call Symbiotic Embedded Machines (SEM), that is specifically designed to inject intrusion detection functionality into the firmware of the device.
Department of Computer Science Columbia University
Defending Embedded Systems with Software Symbiotes
Reference - Framework for notifying a directory service of authentication events processed outside the directory service - Oracle International Corp
Methods, systems and machine-readable media for authenticating an end user for a client application are disclosed. According to one embodiment of the invention, a method of authenticating an end user for a client application using a directory service having an authentication control policy that tracks failed authentication attempts and allows lock out of an account after a predetermined number of failures comprises receiving end user identity information and security information at the client application; sending a search request to the directory service for an entry associated with the end user identity information and, if a match is found, receiving a authentication token from the directory service associated with the end user identity information; comparing the received authentication token with the security information; if the authentication token matches the security information, sending a request to update the directory service to indicate that successful authentication of the end user has occurred; and if the authentication token does not match the security information, sending a request to update the directory service to indicate that a failed attempt at authentication of the end user has occurred.
Framework for notifying a directory service of authentication events processed outside the directory service
Reference - /GS (Buffer Security Check) - Microsoft Docs
Reference - CAR-2019-04-002: Generic Regsvr32 - MITRE
Regsvr32 can be used to execute arbitrary code in the context of a Windows signed binary, which can be used to bypass application whitelisting. This analytic looks for suspicious usage of the tool. It's not likely that you'll get millions of hits, but it does occur during normal activity so some form of baselining would be necessary for this to be an alerting analytic. Alternatively, it can be used for hunt by looking for new or anomalous DLLs manually.
Reference - Guards for application in software tamperproofing - Purdue Research Foundation
A method of protecting a software program from unauthorized modification, and a system for practicing the method. The method utilizes self-protecting software code. Armed internally with self-defensive mechanisms, a self-protecting software program is tamper-resistant. Whenever its integrity is compromised, a self-protecting software program may become unusable due to software program crashes or other errors, or may generate subtle errors that do not immediately result render the program unusable but still result in incorrect software program execution. A self-protecting software program also may be able to repair itself to restore the integrity of its damaged code. The system comprises a computer program for automatically adding self-protection features to a software program.
Hoi Chang; Mikhail J. Atallah; John R. Rice
Guards for application in software tamperproofing
Reference - Hardware-assisted system and method for detecting and analyzing system calls made to an operting system kernel - Endgame Inc
The present disclosure relates to a system and method for monitoring system calls to an operating system kernel. A performance monitoring unit is used to monitor system calls and to gather information about each system call. The information is gathered upon interrupting the system call and can include system call type, parameters, and information about the calling thread/process, in order to determine whether the system call was generated by malicious software code. Potentially malicious software code is nullified by a malicious code counter-attack module.
This patent describes a technique for monitoring system calls to detect malicious software code. A system call monitoring module operates at the kernel level and traps system calls. Monitoring data includes: * information about the path to the file to be accessed by a system call. * the memory address or range of addresses to be accessed by a system call. * the context for the thread within operating system that will be interrupted by a system call. * the type of system call information about the socket that is being used by system call in order to send or receive data. * the history of system calls in order to monitor for specific sequences of system calls. * the frequency or periodicity of a particular system call or set of systems calls. Captured system call data is analyzed using data analysis algorithms such as machine learning algorithms, artificial intelligence algorithms, pattern recognition algorithms, or other known data analysis techniques. An alert is generated if it is likely that the system call was generated by malicious software code.
Hardware-assisted system and method for detecting and analyzing system calls made to an operting system kernel
Reference - Heuristic botnet detection - Palo Alto Networks Inc
In some embodiments, heuristic botnet detection is provided. In some embodiments, heuristic botnet detection includes monitoring network traffic to identify suspicious network traffic; and detecting a bot based on a heuristic analysis of the suspicious network traffic behavior using a processor, in which the suspicious network traffic behavior includes command and control traffic associated with a bot master. In some embodiments, heuristic botnet detection further includes assigning a score to the monitored network traffic, in which the score corresponds to a botnet risk characterization of the monitored network traffic (e.g., based on one or more heuristic botnet detection techniques); increasing the score based on a correlation of additional suspicious behaviors associated with the monitored network traffic (e.g., based on one or more heuristic botnet detection techniques); and determining the suspicious behavior is associated with a botnet based on the score.
This patent describes detecting botnets using heuristic analysis techniques on collected network flows. The heuristic techniques include: * Identifying suspicious traffic patterns to detect command and control traffic ex. periodically visiting a known malware URL, a host visiting a malware domain twice every 5 hour and 14 minutes (this is a specific pattern for a variant of Swizzor botnets). * Identifying non-standard behaviors such as connecting to a non-standard HTTP port for HTTP traffic, visiting a non-existent domain, downloading executable files with non-standard executable file extensions, communicating using HTTP header with a shorter than common length * Analyzing visited domain information to identify the following: visiting a domain with a domain name that is longer than a common domain name length, visiting a dynamic DNS domain, visiting a fast-flux domain, and visiting a recently created domain. A score is determined based on these factors and if the score is over a threshold, a responsive action is performed.
Reference - CAR-2016-03-001: Host Discovery Commands - MITRE
When entering on a host for the first time, an adversary may try to discover information about the host. There are several built-in Windows commands that can be used to learn about the software configurations, active users, administrators, and networking configuration. These commands should be monitored to identify when an adversary is learning information about the system and environment. The information returned may impact choices an adversary can make when establishing persistence, escalating privileges, or moving laterally. Because these commands are built in, they may be run frequently by power users or even by normal users. Thus, an analytic looking at this information should have well-defined white- or blacklists, and should consider looking at an anomaly detection approach, so that this information can be learned dynamically.
CAR-2016-03-001: Host Discovery Commands
Reference - How ASLR protects Linux systems from buffer overflow attacks - Network World
ASLR (Address Space Layout Randomization) is a memory exploitation mitigation technique used on both Linux and Windows systems. Learn how to tell if it's running, enable/disable it, and get a view of how it works.
How ASLR protects Linux systems from buffer overflow attacks
Reference - How Does Antivirus Quarantine Work? - Safety Detectives
Your antivirus has just finished a regular scan and it’s asking whether you want to quarantine the virus it’s found. You click ‘yes’ without putting much thought into what’s actually happening. But what does quarantining actually mean, what does it do and is it safe for your computer? It’s important to understand the details so that you know what’s happening when you send infected files into quarantine.
Reference - How to change registry values or permissions from a command line or a script
This article describes how to change registry values or permissions from a command line or a script. Applies to: Windows 10 - all editions, Windows Server 2012 R2 Original KB number: 264584
How to change registry values or permissions from a command line or a script
Reference - How trust relationships work for resource forests in Azure Active Directory Domain Services
Active Directory Domain Services (AD DS) provides security across multiple domains or forests through domain and forest trust relationships. Before authentication can occur across trusts, Windows must first check if the domain being requested by a user, computer, or service has a trust relationship with the domain of the requesting account.
How trust relationships work for resource forests in Azure Active Directory Domain Services
Reference - IEEE Standard for Local and Metropolitan Area Networks - Station and Media Access Control Connectivity Discovery
IEEE Standard for Local and Metropolitan Area Networks - Station and Media Access Control Connectivity Discovery
Reference - Identification and extraction of key forensics indicators of compromise using subject-specific filesystem views
A stackable filesystem that transparently tracks process file writes for forensic analysis. The filesystem comprises a base filesystem, and an overlay filesystem. Processes see the union of the upper and lower filesystems, but process writes are only reflected in the overlay. By providing per-process views of the filesystem using this stackable approach, a forensic analyzer can record a process's file-based activity-i.e., file creation, deletion, modification. These activities are then analyzed to identify indicators of compromise (IoCs). These indicators are then fed into a forensics analysis engine, which then quickly decides whether a subject (e.g., process, user) is malicious. If so, the system takes some proactive action to alert a proper authority, to quarantine the potential attack, or to provide other remediation. The approach enables forensic analysis without requiring file access mediation, or conducting system event-level collection and analysis, making it a lightweight, and non-intrusive solution.
Frederico Araujo; Anne E. Kohlbrenner; Marc Philippe Stoecklin; Teryl Paul Taylor
Identification and extraction of key forensics indicators of compromise using subject-specific filesystem views
Reference - Identifying a denial-of-service attack in a cloud-based proxy service - Cloudfare Inc.
A cloud-based proxy service identifies a denial-of-service (DoS) attack including determining that there is a potential DoS attack being directed to an IP address of the cloud-based proxy service; and responsive to determining that there are a plurality of domains that resolve to that IP address, identifying the one of the plurality of domains that is the target of the DoS attack. The domain that is under attack is identified by scattering the plurality of domains to resolve to different IP addresses, where a result of the scattering is that each of those domains resolves to a different IP address, and identifying one of those plurality of domains as the target of the DoS attack by determining that there is an abnormally high amount of traffic being directed to the IP address in which that domain resolves.
Lee Hahn Holloway, Srikanth N. Rao, Matthew Browning Prince, Matthieu Philippe Francois Tourne, Ian Gerald Pye, Ray Raymond Bejjani, Terry Paul Rodery, Jr.
Identifying a denial-of-service attack in a cloud-based proxy service
Return-oriented programming (ROP) has become the primary exploitation technique for system compromise in the presence of non-executable page protections. ROP exploits are facilitated mainly by the lack of complete address space randomization coverage or the presence of memory disclosure vulnerabilities, necessitating additional ROP-specific mitigations. In this paper we present a practical runtime ROP exploit prevention technique for the protection of thirdparty applications. Our approach is based on the detection of abnormal control transfers that take place during ROP code execution. This is achieved using hardware features of commodity processors, which incur negligible runtime overhead and allow for completely transparent operation without requiring any modifications to the protected applications. Our implementation for Windows 7, named kBouncer, can be selectively enabled for installed programs in the same fashion as user-friendly mitigation toolkits like Microsoft's EMET. The results of our evaluation demonstrate that kBouncer has low runtime overhead of up to 4%, when stressed with specially crafted workloads that continuously trigger its core detection component, while it has negligible overhead for actual user applications. In our experiments with in-thewild ROP exploits, kBouncer successfully protected all tested applications, including Internet Explorer, Adobe Flash Player, and Adobe Reader.
Vasilis Pappas, Michalis Polychronakis, Angelos D. Keromytis Columbia University
Transparent ROP Exploit Mitigation using Indirect Branch Tracing
Reference - Inferential exploit attempt detection - Crowdstrike Inc
A security agent implemented on a monitored computing device is described herein. The security agent is configured to detect an action of interest (AoI) that may be probative of a security exploit and to determine a context in which that AoI occurred. Based on that context, the security agent is further configured to decide whether the AoI is a security exploit and can take preventative action to prevent the exploit from being completed. Determining that the AoI includes the security exploit is based at least in part on one or more of: determining that the return address is outside memory previously allocated for an object; determining that the object identifier is associated with a vulnerable object; determining that permissions of the memory region include two or more of read, write, and execute; or determining that the memory region is one page in length. Determining that the return address is outside memory previously allocated for an object and the method further including treating code that the return address points to as malicious code.
Daniel W. Brown; Ion-Alexandru Ionescu; Loren C. Robinson
Reference - Instant process termination tool to recover control of an information handling system - Dell Products LP
A method and system for automatic termination of unauthorized malevolent processes operating on an information handling system. A list of authenticated and essential process list is stored on the information handling system. Unauthorized processes not contained on the list can be automatically terminated by the user by invoking the present invention with a single click of a mouse or pointer device on an icon residing on the display screen of the information handling system. The offending processes are immediately terminated without generating a user prompt, which would ordinarily provide sufficient time for the malware to spawn additional offending processes. The present invention also provides significant means to recover control of a malware-infected information handling system in order to use repair tools and utilities. The present invention can be deployed at the time of manufacture of an information handling system or independently installed by a user.
Instant process termination tool to recover control of an information handling system
Reference - Integrity assurance through early loading in the boot phase - Crowdstrike Inc
Techniques utilizing library and pre-boot components to ensure that a driver associated with a kernel-mode component is initialized before other drivers during a boot phase are described herein. The library component is processed during a boot phase; the pre-boot component, which may be an alternative to the library component, is processed during a pre-boot phase. By ensuring that the driver is the first driver initialized, the components enable the driver to launch the kernel-mode component before other drivers are initialized. The library component may also determine whether another driver is to be initialized before the kernel-mode component driver, may ensure that kernel-mode component driver is initialized first, and may alert the kernel-mode component. Also, the library component may retrieve information that is to be deleted by the operating system before initialization of drivers and may provide that information to the kernel-mode component.
To compromise software or to gain control of a host device, a security exploit can modify driver initialization order used by an operating system and place a driver associated with the security exploit first in a list of drivers initialized by the operating system. This patent describes ensuring that a driver associated with the agent is initialized first. To ensure the driver is initialized first, a dependent DLL associated with the driver is configured to be processed before other dependent DLLs. The dependent DLL can be configured to be processed first by various methods, for example if processing is done in alphabetical order, changing its name to be processed first. The dependent DLL, once processed, executes a number of operations to ensure the driver associated with the agent is initialized first. Furthermore, if the initialization order is modified, an alert is provided to the kernel-mode component that notifies the kernel-mode component it was not first and the order had to be altered. It can then take additional actions such as additional monitoring or remediation.
Integrity assurance through early loading in the boot phase
Reference - Intrusion detection using a heartbeat - Sophos Ltd
A variety of techniques are disclosed for detection of advanced persistent threats and similar malware. In one aspect, the detection of certain network traffic at a gateway is used to trigger a query of an originating endpoint, which can use internal logs to identify a local process that is sourcing the network traffic. In another aspect, an endpoint is configured to periodically generate and transmit a secure heartbeat, so that an interruption of the heartbeat can be used to signal the possible presence of malware. In another aspect, other information such as local and global reputation information is used to provide context for more accurate malware detection.
This patent describes a health monitor deployed on an endpoint that uses a heartbeat to periodically communicate status to a gateway's remote health monitor. The endpoint health monitor issues a heartbeat for satisfactory status of the endpoint using factors such as: * checking the status of individual software items executing on the endpoint * checking that antivirus and other security software is up to date (e. g., with current virus definition files) and running correctly * checking the integrity of cryptographic key stores * checking other hardware or software components of the endpoint as necessary or helpful for health monitoring A disappearance of the heartbeat from the endpoint may indicate that the endpoint has been compromised.
Reference - Isolation of applications within a virtual machine - Bromium, Inc.
Approaches for launching an application within a virtual machine. In response to receiving a request to launch an application, a device instantiates, without human intervention and based on a policy, a virtual machine in which the application is to be launched. The policy determines which resources of a device, such as a mobile device or computer system, are accessible to the virtual machine. The policy may, but need not, determine whether the virtual machine has access to a type of resource which obligates the user of the device to make a monetary payment for the user of the resource.
Gaurav Banga, Sergei Vorobiev, Deepak Khajuria, Vikram Kapoor, Ian Pratt, Simon Crosby, Adrian Taylor
Isolation of applications within a virtual machine
Reference - LUKS1 On-Disk Format SpecificationVersion 1.2.3
LUKS is short for "Linux Unified Key Setup". It has initially been developed to remedy the unpleasantness a user experienced that arise from deriving the encryption setup from changing user space, and forgotten command line arguments. The result of this changes are an unaccessible encryption storage. The reason for this to happen was, a unstandardised way to read, process and set up encryption keys, and if the user was unlucky, he upgraded to an incompatible version of user space tools that needed a good deal of knowledge to use with old encryption volumes.
LUKS1 On-Disk Format SpecificationVersion 1.2.3
Reference - MGT516: Managing Security Vulnerabilities: Enterprise and Cloud
Vulnerability, patch, and configuration management are not new security topics. In fact, they are some of the oldest security functions. Yet, we still struggle to manage these capabilities effectively. The quantity of outstanding vulnerabilities for most large organizations is overwhelming, and all organizations struggle to keep up with the never-ending onslaught of new vulnerabilities in their infrastructure and applications. When you add in the cloud and the increasing speed with which all organizations must deliver systems, applications, and features to both their internal and external customers, security may seem unachievable. This course will show you the most effective ways to mature your vulnerability management program and move from identifying vulnerabilities to successfully treating them. 16 Cyber42 and lab exercises
MGT516: Managing Security Vulnerabilities: Enterprise and Cloud
Reference - Malicious relay detection on networks - VECTRA NETWORKS Inc
A system and method for detecting malicious relay communications is disclosed. Network communications can be received and analyzed using such network components as a network switch. The received traffic can be parsed into sessions. Relay metadata can be extracted from the sessions and further be used to categorize the sessions into one or more types of relay metadata behaviors. Once a significant amount of sessions are detected an alarm may be triggered and/or alarm data may be generated for analysis by network security administrators.
Ryan James PRENGER; Nicolas BEAUCHESNE; Karl Matthew LYNN
This patent describes a technique for detecting relay networks, i.e. an attacker outside of the organization's network takes control of an internal host to be used as a source of attacks against other internal targets or exfiltrate data out of the organization. In this defensive technique, metadata from collected network packet captures is extracted to categorize network sessions using known relay behaviors. Information such as the number of bytes sent to and from a potential internal relay host, time of session initiation, packet contents, packet size, flow direction, and packet arrival time statistics are used to categorize the sessions and identify relay behavior. This technique assumes that relay network connections' inter-packet arrival times exhibit a high degree of variance in comparison to standard client-to-server connections. If enough evidence of relay behavior is gathered about a given internal host, the host is identified as suspicious and an alert is generated.
Reference - Malware analysis system - Palo Alto Networks Inc
In some embodiments, a malware analysis system includes receiving a potential malware sample from a firewall; analyzing the potential malware sample using a virtual machine to determine if the potential malware sample is malware; and automatically generating a signature if the potential malware sample is determined to be malware. In some embodiments, the potential malware sample does not match a preexisting signature, and the malware is a zero-day attack.
This patent describes a VM sandbox environment that uses heuristic based analysis techniques performed in real-time during a file transfer to determine if the file is malicious. A new signature can then be generated and distributed to automatically block future file transfer requests to download the malicious file.
Reference - Malware detection in event loops - Crowdstrike Inc
Example techniques locate or identify malware based on events from or at monitored computing devices. A control unit can detect a sequence of events of various types. The control unit can locate a loop within the sequence of events based at least in part on relative frequencies of the event types. The control unit can determine a distribution of event types of the events within the loop, and determining that software running the sequence is associated with malware based at least in part on the distribution of event types within the loop. In some examples, the control unit can locate a point of commonality among a plurality of stack traces associated with respective events within the loop. The control unit can determine a malware module comprising the point of commonality.
The patent describes determining if a sequence of events associated with a process are associated with malware. Based on the relative frequency of events, a loop within a sequence of events is located and a distribution of the events within the loop is determined. The distribution of events is then compared against a catalog of distributions to determine if it is associated with malware.
Reference - Malware detection using local computational models - Crowdstrike Inc
Example techniques herein determine that a trial data stream is associated with malware ("dirty") using a local computational model (CM). The data stream can be represented by a feature vector. A control unit can receive a first, dirty feature vector (e.g., a false miss) and determine the local CM based on the first feature vector. The control unit can receive a trial feature vector representing the trial data stream. The control unit can determine that the trial data stream is dirty if a broad CM or the local CM determines that the trial feature vector is dirty. In some examples, the local CM can define a dirty region in a feature space. The control unit can determine the local CM based on the first feature vector and other clean or dirty feature vectors, e.g., a clean feature vector nearest to the first feature vector.
Sven Krasser,David Elkind, Patrick Crenshaw, Kirby James Koster
Malware detection using local computational models
Reference - Method and Apparatus for Detecting Malicious Websites - Endgame Inc
A method and apparatus for detecting malicious websites is disclosed.
John Burnet MUNRO, IV; Jason Aaron Trost; Zachary Daniel HANIF
This patent describes a domain classification engine on the host computer that analyzes URLs clicked by a user or entered into a web browser to visit a website. URL analysis is done by using a combination of techniques: * Feature extraction: A URL is analyzed against features associated with suspicious URLs such as % of longest consecutive digits in a subdomain, % of longest repeated characters in a subdomain, % of vowels in a high level domain. * Markov analysis: The probability of a digit occurring in normal language given the preceding two digits is determined. For example, if the received URL is 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 will be determined. The probability of each digit is then multiplied to get a probability for the whole domain name. Probabilities are determined based on a database of existing usage, such as a dictionary, or a list of known good domain names * Domain names are compared against an existing dataset of known unauthorized domain names. A rating is developed based on the results of these techniques, and if the rating is over a set threshold, an action is taken such as blocking access or generating an alert.
Method and Apparatus for Detecting Malicious Websites
Reference - Method and apparatus for increasing the speed at which computer viruses are detected - McAfee LLC
The method and apparatus for increasing the speed at which computer viruses are detected stores initial state information concerning the file or volume which is being examined for a virus. This information is stored in a cache in a non-volatile storage medium and when files are subsequently scanned for viruses, the current state information is compared to the initial state information stored in the cache. If the initial state information differs from the current state information then the file or volume is scanned for viruses which change the state information of the file or volume. If the initial state information and current state information is the same then the file or volume is scanned for a subset of viruses which do not change the state information.
Method and apparatus for increasing the speed at which computer viruses are detected
Reference - Method and apparatus for utilizing a token for resource access - Rsa Security Inc.
A method and apparatus for utilizing a token which is preferably a "dumb token" to provide secure access by authorized users to a selected resource. The token stores a secret user code in machine readable form, which code is read by a token processor. The token processor also receives a time-varying value and an algorithm, both of which may be stored or generated at either the token or the token processor and preferably a secret personal identification code which may be inputted at the token, but is preferably inputted at the token processor. The secret user code, time-varying value and secret personal identification code are then algorithmically combined by the algorithm, preferably in the token processor, to generate a one-time nonpredictable code which is transmitted to a host processor. The host processor utilizes the received one-time nonpredictable code to determine if the user is authorized access to the resource and grants access to the resource if the user is determined to be authorized. The system may be modified to operate in query/response mode. The token processor may be any of a variety of available portable remote processors or may be a device such as a telephone which is equipped with card or other token reader and with processing capability.
Method and apparatus for utilizing a token for resource access
Reference - Method and system for controlling communication ports
A method for limiting devices and controlling the applications executed from USB ports on personal computers (PCs).
Method and system for controlling communication ports
Reference - Method and system for detecting algorithm-generated domains - VECTRA NETWORKS Inc
A method and system for detecting algorithm-generated domains (AGDs) is disclosed wherein domain names requested by an internal host are categorized or classified using curated data sets, active services (e.g. Internet services), and certainty scores to match domain names to domain names or IP addresses used by command and control servers.
James Patrick HARLACHER; Aditya Sood; Oskar Ibatullin
This patent describes detecting algorithm generated domains (AGD). DNS requests and responses are analyzed by first checking whether the domain matches existing data sets that specify different types of AGDs with known characteristics, such as Evil Twin Domains, Sinkholed domains, sleeper cells, ghost domains, parked domains, and/or bulk-registered domains. In addition to comparing domains against known data sets, the following information is collected to perform analysis: * IP Information: checks for information known about the IP addresses returned in the DNS response, including the number of IP addresses returned, the registered owners of the IP addresses, or different IP addresses returned for the same domain (IP fluxing) * Domain Registration: examines the domain registration date, domain update date, domain expiration date, registrant identity, and authorized name servers associated with a specific domain name. * Domain Popularity: provides information on the popularity of a domain name. Based on analysis of these factors a score is developed; if the score is above a certain threshold, an alert is generated.
Method and system for detecting algorithm-generated domains
Reference - Method and system for detecting external control of compromised hosts - VECTRA NETWORKS Inc
A detection engine may be implemented by receiving network traffic and processing the traffic into one or more session datasets. Sessions not initiated by an internal host may be discarded. The frequency between the communication packets from the internal host to external host may be grouped or processed into rapid-exchange instances. The number of rapid-exchange instances, the time intervals between them, and/or the rhythm and directions of the initiation of the instances may be analyzed to determine that a human actor is manually controlling the external host. In some embodiments, when it is determined that only one human actor is involved, alarm data may be generated that indicates that a network intrusion involving manual remote control has occurred or is underway.
This patent describes detecting an external attacker taking remote control of an internal host. Detection includes identifying sessions where the external host controls the internal host in the opposite direction the session was initiated. The number of rapid-exchange communication instances (i.e, communications that occur between the two hosts with little silence gap), the time intervals between them, and/or the rhythm and direction of the instances, are analyzed to determine if an external human actor is manually controlling the internal host.
Method and system for detecting external control of compromised hosts
Reference - Method and system for detecting malicious payloads - Vectra Networks Inc
Disclosed is an improved method, system, and computer program product for identifying malicious payloads. The disclosed approach identifies potentially malicious payload exchanges which may be associated with payload injection or root-kit magic key usage. Some examples of data inputs: Information for clients and servers, such as IP address and host information Payloads for both clients and servers Amount of data being transferred Duration of communications Length of time delay between client request and server response
Extraction of network flow data and using unsupervised machine learning to create a standard baseline. During the monitoring phase, abnormal network metadata will result in an alert.
Method and system for detecting malicious payloads
Reference - Method and system for detecting restricted content associated with retrieved content - Sophos Ltd
In embodiments of the present invention improved capabilities are described for detecting restricted content associated with retrieved content. The method and system may include receiving a client request for content, saving contextual information from the client request, presenting retrieved content in response to the client request, and presenting the contextual information from the client request, and retrieved content, to a scanning facility. The scanning facility may utilize the contextual information from the client request to aid in the detection of restricted content associated with retrieved content.
Fraser Howard; Paul Baccas; Vanja Svajcer; Benjamin John Godwood; William James McCourt
This patent describes analyzing contextual information of a Uniform Resource Identifier (URI), such as source or origin of the request URI, patterns in the way the URI is delivered, and the locale of the URI. The contextual information is sent to a scanning facility which uses that information along with a blacklist of known malicious domain names, locations, patterns, etc. to block retrieved content associated with the request URI.
Method and system for detecting restricted content associated with retrieved content
Reference - Method and system for detecting suspicious administrative activity - Vectra Networks Inc
Disclosed is an improved approach for identifying suspicious administrative host activity within a network. Network traffic is examined to learn the behavior of hosts within a network. This provides an effective way of determining whether or not a host is performing suspicious activity over an administrative protocol.
Collect network traffic metadata directed at administrative services over a period of time to establish a baseline. This baseline is then used to determine suspicious activity that falls outside of the established baseline.
Method and system for detecting suspicious administrative activity
Reference - Method and system for detecting threats using metadata vectors - VECTRA NETWORKS Inc
An approach for detecting network attacks using metadata vectors may initially involve receiving network communications or packets, extracting metadata items from the packets. The metadata items describe the communications without requiring deep content inspection of the data payload or contents. The communications may be clustered into groups using the metadata items. If a cluster exceeds a threshold, an alarm may be generated.
Nicolas BEAUCHESNE; David Lopes Pegna; Karl Lynn
This patent describes detecting network threats by first passively collecting network traffic and storing it for processing. Metadata from network traffic such as packet header information or information about a session (ex. time between request/responses) is extracted. After the metadata is extracted, the data is grouped into cluster maps of matching events to track how many instances of a network communication have occurred, such as five requests sent and five responses received. Threshold limits are set on the clusters to monitor them and if a cluster grows too large (ex. ten instances of requests and responses) this can correspond to unauthorized behavior. This method might detect, for example, a network attack using malicious payloads with automated scripts, in which a bot sends replicated malicious payloads to the same destination port.
Method and system for detecting threats using metadata vectors
Reference - Method and system for detecting threats using passive cluster mapping - Vectra Networks Inc
An approach for detecting network threats is disclosed, that may involve receiving network traffic, plotting the network traffic in a n-dimensional feature space to form a network map, generating a client signature at least by placing new client points in the map, setting a threshold, and generating an alarm if one or more client activity points exceed the threshold. In some embodiments, the network map and the client signature are updated using sliding windows and distance calculations.
This patent describes detecting network threats by first passively collecting network traffic and storing it for processing. The stored network traffic data is used to map network events to create a cluster map. Events are network activity associated with clients, servers, or control modules such as a Kerberos Domain Controller (KDC); account information; services accessed by the client; or the number of times a service is accessed. Events that exceed a threshold from a center of gravity point of a cluster are identified as suspicious activity and an alert is generated.
Method and system for detecting threats using passive cluster mapping
Reference - Method and system for providing software updates to local machines
Method and system for providing software updates to local machines
Reference - Method and system for UDP flood attack detection - Riorey LLC
A system and method is provided to identify UDP attacks. A processor determines a spectral density of packet timing intervals, a natural distance between the spectral density and a uniform distribution, and a non-linear amplifier applying a non-linear amplification to the natural distance to detect a denial-of-service attack. It uses the concept of traffic statistics analysis, i.e., spectral densities of arrived-packet timing intervals, calculates the KL-distance measurement and makes decision based on the output of a non-linear Gaussian amplifier, with which one can easily adjust the amplifier via selecting different parameters of mean and variance to satisfy system requirements of false-positive and false-negative UDP attack detections.
Method and system for UDP flood attack detection
A method for encryption and sealing of a plaintext file by hashing the plaintext file to produce a plaintext hash, encrypting the plaintext file to produce ciphertext, hashing the ciphertext to produce a ciphertext hash, hashing the plaintext hash and the ciphertext hash to produce a result hash, and sealing the ciphertext together with the result hash.
Robert R. Jueneman, Duane J. LINSENBARDT, John N. Young, William Reid Carlisle, Burton George Tregub
Reference - Method using kernel mode assistance for the detection and removal of threats which are actively preventing detection and removal from a running system - Symantec Corporation
A user mode application component invokes the assistance of a kernel mode driver component to detect and/or remediate malicious code on a computer system. The user mode application may include code that detects, for example, spyware and computer viruses, from user mode and when appropriate takes protective action when malicious code is detected. In one aspect, when the user mode application is unable to perform a selected operation in attempting to detect and/or take protective action, the user mode application invokes a kernel mode driver for assistance. The kernel mode driver assists user mode application in detecting malicious code and/or taking protective action by enabling or otherwise performing a selected operation for the user mode application.
Adam Glick, Patrick Gardner, Pieter Viljoen
This patent describes detecting registry changes using a prohibited change heuristic or a database of prohibited functions/function parameters.
Method using kernel mode assistance for the detection and removal of threats which are actively preventing detection and removal from a running system
Reference - Mission Dependency Modeling for Cyber Situational Awareness
This paper describes a hierarchical graph-based model that captures mission dependencies at various levels of abstraction, showing interdependencies among mission objectives, tasks, information, and cyber assets. For this work, we employ established tools within a structured methodology for cyber resiliency analysis. Our model is focused on a strategic-level military scenario defined in a formal Request for Information (RFI) to industry and research partners by the NATO Multinational Cyber Defense Capability Development (MN CD2) Work Package 2 (WP2). We enhance this scenario with additional mission and operational context, and then build a mission dependency model for the enhanced scenario. It is anticipated that our mission dependency model will be part of an upcoming demonstration of cyber defense situational awareness capabilities in a NATO Communications and Information (NCI) Agency test environment, integrated with data sources that represent the operational military environment.
William Heinbockel, Steven Noel, James Curbo
Mission Dependency Modeling for Cyber Situational Awareness
Reference - Mock attack cybersecurity training system and methods - WOMBAT SECURITY TECHNOLOGIES Inc
A training system senses a user action that may expose the user to a threat, such as a cybersecurity threat. The user action may be in response to a mock attack delivered via a messaging service, a wireless communication service, a fake malware application or another device, service, system or mechanism. The system selects a training action from a collection of available training actions and causes the training action to be delivered to the user.
Norman Sadeh-Koniecpol, Kurt Wescoe, Jason Brubaker, Jason Hong
Mock attack cybersecurity training system and methods
Reference - Modeling user access to computer resources - Daedalus Group LLC (formerly IBM)
Embodiments of the invention provide a method for detecting changes in behavior of authorized users of computer resources and reporting the detected changes to the relevant individuals. The method includes evaluating actions performed by each user against user behavioral models and business rules. As a result of the analysis, a subset of users may be identified and reported as having unusual or suspicious behavior. In response, the management may provide feedback indicating that the user behavior is due to the normal expected business needs or that the behavior warrants further review. The management feedback is available for use by machine learning algorithms to improve the analysis of user actions over time. Consequently, investigation of user actions regarding computer resources is facilitated and data loss is prevented more efficiently relative to the prior art approaches with only minimal disruption to the ongoing business processes.
Joseph P. Bigus, Leon Gong, Christoph Lingenfelder
Modeling user access to computer resources
Reference - Modification of a Server to Mimic a Deception Mechanism - Acalvio Technologies Inc
Provided are devices, computer-program products, and methods (e.g., methods implemented by a production system or security agent program or process) for providing services on a production system to mimic a deception mechanism. For example, a method can include determining a deception characteristic of a deception mechanism and determining a production characteristic of the production system. The method can further include determining an additional service or a modification of an existing service of the production system using the deception characteristic and the production characteristic. In some cases, the additional service and/or the modification can be a deterrent to potential attackers of the production system. The method can further include modifying the production system to mimic the deception mechanism, including adding the additional service to the production system or modifying the existing service using the modification.
Modification of a Server to Mimic a Deception Mechanism
Online Hash Checker for Virustotal and Other Services
Reference - NIST RMF Quick Start Guide - Assess Step - Frequently Asked Questions (FAQ)
Once security and privacy controls are implemented, they need to be evaluated for correctness and effectiveness. After the initial assessment is completed and the system enters the operations/maintenance phase of the system development life cycle, the controls are assessed on an ongoing basis according to the organization and system’s continuous monitoring plans. The ongoing assessment supports the authorizing official’s decision to continue or discontinue the system’s authorization to operate. Control effectiveness assessments are performed by an independent third-party assessor or assessment team if the system categorization is moderate or high.
NIST RMF Quick Start Guide - Assess Step - Frequently Asked Questions (FAQ)
Reference - NIST Special Publication 800-160 Volume 1 - System Security Engineering
With the continuing frequency, intensity, and adverse consequences of cyber-attacks, disruptions, hazards, and other threats to federal, state, and local governments, the military, businesses, and the critical infrastructure, the need for trustworthy secure systems has never been more important to the long-term economic and national security interests of the United States. Engineering-based solutions are essential to managing the growing complexity, dynamicity, and interconnectedness of today’s systems, as exemplified by cyber-physical systems and systems-of-systems, including the Internet of Things. This publication addresses the engineering-driven perspective and actions necessary to develop more defensible and survivable systems, inclusive of the machine, physical, and human components that compose the systems and the capabilities and services delivered by those systems. It starts with and builds upon a set of well-established International Standards for systems and software engineering published by the International Organization for Standardization (ISO), the International Electrotechnical Commission (IEC), and the Institute of Electrical and Electronics Engineers (IEEE) and infuses systems security engineering methods, practices, and techniques into those systems and software engineering activities. The objective is to address security issues from a stakeholder protection needs, concerns, and requirements perspective and to use established engineering processes to ensure that such needs, concerns, and requirements are addressed with appropriate fidelity and rigor, early and in a sustainable manner throughout the life cycle of the system.
Ron Ross, Michael McEvilley, and Janet Carrier Oren
NIST Special Publication 800-160 Volume 1 - Systems Security Engineering
Reference - NIST Special Publication 800-37 Revision 2 - Risk Management Framework for Information Systems and Organizations
This publication describes the Risk Management Framework (RMF) and provides guidelines for applying the RMF to information systems and organizations. The RMF provides a disciplined, structured, and flexible process for managing security and privacy risk that includes information security categorization; control selection, implementation, and assessment; system and common control authorizations; and continuous monitoring. The RMF includes activities to prepare organizations to execute the framework at appropriate risk management levels. The RMF also promotes near real-time risk management and ongoing information system and common control authorization through the implementation of continuous monitoring processes; provides senior leaders and executives with the necessary information to make efficient, cost-effective, risk management decisions about the systems supporting their missions and business functions; and incorporates security and privacy into the system development life cycle. Executing the RMF tasks links essential risk management processes at the system level to risk management processes at the organization level. In addition, it establishes responsibility and accountability for the controls implemented within an organization’s information systems and inherited by those systems.
NIST Special Publication 800-37 Revision 2 - Risk Management Framework for Information Systems and Organizations
Reference - NIST Special Publication 800-53A Revision 5 - Assessing Security and Privacy Controls in Information Systems and Organizations
This publication provides a methodology and set of procedures for conducting assessments of security and privacy controls employed within systems and organizations within an effective risk management framework. The assessment procedures, executed at various phases of the system development life cycle, are consistent with the security and privacy controls in NIST Special Publication 800-53, Revision 5. The procedures are customizable and can be easily tailored to provide organizations with the needed flexibility to conduct security and privacy control assessments that support organizational risk management processes and are aligned with the stated risk tolerance of the organization. Information on building effective security and privacy assessment plans is also provided with guidance on analyzing assessment results.
NIST Special Publication 800-53A Revision 5 - Assessing Security and Privacy Controls in Information Systems and Organizations
Reference - NISTIR 8011 Volume 1 - Automation Support for Security Control Assessments
This volume introduces concepts to support automated assessment of most of the security controls in NIST Special Publication (SP) 800-53. Referencing SP 800-53A, the controls are divided into more granular parts (determination statements) to be assessed. The parts of the control assessed by each determination statement are called control items. The control items are then grouped into the appropriate security capabilities. As suggested by SP 800-53 Revision 4, security capabilities are groups of controls that support a common purpose. For effective automated assessment, testable defect checks are defined that bridge the determination statements to the broader security capabilities to be achieved and to the SP 800-53 security control items themselves. The defect checks correspond to security sub-capabilities-called sub-capabilities because each is part of a larger capability. Capabilities and sub-capabilities are both designed with the purpose of addressing a series of attack steps. Automated assessments (in the form of defect checks) are performed using the test assessment method defined in SP 800-53A by comparing a desired and actual state (or behavior).
Kelley Dempsey, Paul Eavy, and George Moore
NIST Interagency Report 8011 Volume 1 - Automation Support for Security Control Assessments
Reference - Network-Based Buffer Overflow Detection by Exploit Code Analysis - Information Security Research Centre
Buffer overflow attacks continue to be a major security problem and detecting attacks of this nature is therefore crucial to network security. Signature based network based intrusion detection systems (NIDS) compare network traffic to signatures modelling suspicious or attack traffic to detect network attacks. Since detection is based on pattern matching, a signature modelling the attack must exist for the NIDS to detect it, and it is therefore only capable of detecting known attacks. This paper proposes a method to detect buffer overflow attacks by parsing the payload of network packets in search of shellcode which is the remotely executable component of a buffer overflow attack. By analysing the shellcode it is possible to determine which system calls the exploit uses, and hence the operation of the exploit. Current NIDS-based buffer overflow detection techniques mainly rely upon specific signatures for each new attack. Our approach is able to detect previously unseen buffer overflow attacks, in addition to existing ones, without the need for specific signatures for each new attack. The method has been implemented and tested for buffer overflow attacks on Linux on the Intel x86 architecture using the Snort NIDS.
Stig Andersson, Andrew Clark, and George Mohay
Network-Based Buffer Overflow Detection by Exploit Code Analysis
Reference - OS Query Windows User Collection Code
Reference - Open source intelligence deceptions - Illusive Networks Ltd
A system to detect attackers who attempt to breach an enterprise network and attackers who have already breached the enterprise network, including an open source intelligence (OSINT) discoverer scanning the Internet to discover data related to an enterprise that is available online, an OSINT replacer generating deceptive files by replacing placeholders within template files with deceptive information, based on the data discovered by the OSINT discoverer, an OSINT distributor planting the deceptive files generated by the OSINT replacer within designated OSINT resources, and a deception management server that alerts an administrator in response to an attacker attempting to make a connection within the network using information in a deceptive file planted by the OSINT distributor.
Hadar Yudovich; Nimrod Lavi; Sharon Bittan; Tom Kahana; Tom Sela
Seems to focus on configuration oriented files to put in decoy hostnames etc. to publish on internet sites, then monitor the decoy "objects".
Reference - Organizational Management in SAP ERP HCM
Reference - CAR-2014-11-002: Outlier Parents of Cmd - MITRE
Many programs create command prompts as part of their normal operation including malware used by attackers. This analytic attempts to identify suspicious programs spawning cmd.exe by looking for programs that do not normally create cmd.exe. While this analytic does not take the user into account, doing so could generate further interesting results. It is very common for some programs to spawn cmd.exe as a subprocess, for example to run batch files or windows commands. However many process don't routinely launch a command prompt - for example Microsoft Outlook. A command prompt being launched from a process that normally doesn't launch command prompts could be the result of malicious code being injected into that process, or of an attacker replacing a legitimate program with a malicious one.
Reference - Password and Key Rotation - SSH
Reference - Pointer Authentication on ARMv8.3
The pointer authentication scheme introduced by ARM is a software security primitive that makes it much harder for an attacker to modify protected pointers in memory without being detected. In this document, we will provide more details about the Pointer Authentication mechanism, provide a security analysis, and discuss the implementation of certain software security countermeasures, such as stack protection and control flow integrity, using the Pointer Authentication primitives.
Reference - Pointer Authentication Project Zero
In this post I examine Apple's implementation of Pointer Authentication on the A12 SoC used in the iPhone XS, with a focus on how Apple has improved over the ARM standard. I then demonstrate a way to use an arbitrary kernel read/write primitive to forge kernel PAC signatures for the A keys, which is sufficient to execute arbitrary code in the kernel using JOP. The technique I discovered was (mostly) fixed in iOS 12.1.3. In fact, this fix first appeared in the 16D5032a beta while my research was still ongoing.
Examining Pointer Authentication on the iPhone XS
Reference - Post sandbox methods and systems for detecting and blocking zero-day exploits via api call validation - K2 Cyber Security Inc
In one aspect, a method useful for monitoring and validating execution of executable binary code, includes the step of disassembling an executable binary code of an application. The method includes the step of detecting and obtaining location and type of an application programming interface (API) call, system call, and privileged instruction that is executed by the executable binary code. The method includes the step of detecting and obtaining return address from an Al call and system call. The method includes the step of validating location of the API call system call, and privileged instruction. The method includes the step of validating return from the API call and system call.
The patent describes a technique for monitoring API calls. Executable binary code of an application is first disassembled and scanned for API calls. Based on the recorded API calls, a rule list is generated. Software hooks are placed in the code for monitoring API calls during program execution and then each API call is validated using the generated rule list to permit or deny execution of API calls. Rules are created that specify the type and location of the API call. For example, data collected for an application can show an API call to libc at address 0x43e0 and an API call by libc at address 0xlfb47. Accordingly, two rules are generated. The first rule specifies the location type and target of the API call at address 0x43e0, as well as the return address. The second rule is for the API call to the kernel and states the target address, return address, instruction, and target type.
Post sandbox methods and systems for detecting and blocking zero-day exploits via api call validation
Reference - CAR-2014-04-003: Powershell Execution - MITRE
PowerShell is a scripting environment included with Windows that is used by both attackers and administrators. Execution of PowerShell scripts in most Windows versions is opaque and not typically secured by antivirus which makes using PowerShell an easy way to circumvent security measures. This analytic detects execution of PowerShell scripts. Powershell can be used to hide monitored command line execution such as: * net use * sc start
Reference - Predicting Domain Generation Algorithms with Long Short-Term Memory Networks
Various families of malware use domain generation algorithms (DGAs) to generate a large number of pseudo-random domain names to connect to a command and control (C&C) server. In order to block DGA C&C traffic, security organizations must first discover the algorithm by reverse engineering malware samples, then generating a list of domains for a given seed. The domains are then either preregistered or published in a DNS blacklist. This process is not only tedious, but can be readily circumvented by malware authors using a large number of seeds in algorithms with multivariate recurrence properties (e.g., banjori) or by using a dynamic list of seeds (e.g., bedep). Another technique to stop malware from using DGAs is to intercept DNS queries on a network and predict whether domains are DGA generated. Such a technique will alert network administrators to the presence of malware on their networks. In addition, if the predictor can also accurately predict the family of DGAs, then network administrators can also be alerted to the type of malware that is on their networks. This paper presents a DGA classifier that leverages long short-term memory (LSTM) networks to predict DGAs and their respective families without the need for a priori feature extraction. Results are significantly better than state-of-the-art techniques, providing 0.9993 area under the receiver operating characteristic curve for binary classification and a micro-averaged F1 score of 0.9906. In other terms, the LSTM technique can provide a 90% detection rate with a 1:10000 false positive (FP) rate---a twenty times FP improvement over comparable methods. Experiments in this paper are run on open datasets and code snippets are provided to reproduce the results.
Jonathan Woodbridge, Hyrum S. Anderson, Anjum Ahuja, Daniel Grant
Predicting Domain Generation Algorithms with Long Short-Term Memory Networks
Reference - Preventing execution of task scheduled malware - McAfee LLC
A method for preventing malware attacks includes the steps of detecting an attempt on an electronic device to access a task scheduler, determining an entity associated with the attempt to access the task scheduler, determining a malware status of the entity, and, based on the malware status of the entity, allowing or denying the attempted access to the task scheduler. The task scheduler is configured to launch one or more applications at a specified time or interval.
Anil Ramabhatta, Harinath Vishwanath Ramachetty, Nandi Dharma Kishore
Access to a job scheduler is intercepted using hooking or file filters to identify and analyze the source files, processes, destination files, or destination servers associated with a scheduled job. The identified servers or files associated with a job are compared against an anti-malware signature database or reputation server to determine if it there is a match. If so, execution is denied and an alert is generated.
Preventing execution of task scheduled malware
Reference - Privacy and security systems and methods of use
Privacy and security systems and methods of use
Reference - Private virtual local area network isolation - Cisco Technology Inc
In one embodiment, a method includes obtaining addresses of end hosts at a switch, the switch configured with a primary virtual local area network and a secondary virtual local area network, creating a private virtual local area network access list comprising the addresses of end hosts permitted to communicate on the secondary virtual local area network, and applying the private virtual local area network access list to interfaces connected to the end hosts permitted to communicate on the secondary virtual local area network. An apparatus is also disclosed.
Private virtual local area network isolation
Reference - CAR-2013-02-003: Processes Spawning cmd.exe - MITRE
The Windows Command Prompt (cmd.exe) is a utility that provides a command line interface to Windows operating systems. It provides the ability to run additional programs and also has several built-in commands such as dir, copy, mkdir, and type, as well as batch scripts (.bat). Typically, when a user runs a command prompt, the parent process is explorer.exe or another instance of the prompt. There may be automated programs, logon scripts, or administrative tools that launch instances of the command prompt in order to run scripts or other built-in commands. Spawning the process cmd.exe from certain parents may be more indicative of malice. For example, if Adobe Reader or Outlook launches a command shell, this may suggest that a malicious document has been loaded and should be investigated. Thus, by looking for abnormal parent processes of cmd.exe, it may be possible to detect adversaries.
CAR-2013-02-003: Processes Spawning cmd.exe
Reference - Protected computing environment - Microsoft Technology Licensing LLC
A method of establishing a protected environment within a computing device including validating a kernel component loaded into a kernel of the computing device, establishing a security state for the kernel based on the validation, creating a secure process and loading a software component into the secure process, periodically checking the security state of the kernel, and notifying the secure process when the security state of the kernel has changed.
Sumedh Barde, Jonathan Schwartz, Reid Kuhn, Alexandre Grigorovitch, Kirt Debique, Chadd Knowlton, James Alkove, Geoffrey Dunbar, Michael Grier, Ming Ma, Chaitanya Upadhyay, Adil Sherwani, Arun Kishan
Reference - Protecting against distributed denial of service attacks - Cisco Technology Inc.
A method for authenticating packet communication traffic includes receiving a data packet sent over a network from a source address to a destination address and reading from the packet a value of a field that is indicative of a number of hops traversed by the packet since having been sent from the source address. The authenticity of the source address is assessed responsive to the value.
Guy Pazi, Anat Bremler-Bar, Rami Rivlin, Dan Touitou
Protecting against distributed denial of service attacks
Reference - Protecting against distributed network flood attacks - Juniper Networks Inc.
A network security device performs a three-stage analysis of traffic to identify malicious clients. In one example, a device includes an attack detection module to, during a first stage, monitor network connections to a protected network device, during a second stage, to monitor a plurality of types of transactions for the plurality of network sessions when a parameter for the connections exceeds a connection threshold, and during a third stage, to monitor communications associated with network addresses from which transactions of the at least one of type of transactions originate when a parameter associated with the at least one type of transactions exceeds a transaction-type threshold. The device executes a programmed action with respect to at least one of the network addresses when the transactions of the at least one of the plurality of types of transactions originating from the at least one network address exceeds a client-transaction threshold.
Krishna Narayanaswamy, Bryan Burns, Venkata Rama Raju Manthena
Protecting against distributed network flood attacks
Reference - Public Key Pinning Extension for HTTP
RFC 7469 describes an HTTP extension that allows web host operators to instruct user agents to remember ('pin') the hosts' cryptographic identities over a period of time. This decreases the risk of MITM attacks due to compromised Certificate Authorities.
Reference - Qualys Network Passive Sensor Getting Started Guide
Qualys Passive Scanning Sensor (PS) continuously monitors all network traffic and flags any asset activity. It identifies and profiles devices the moment they connect to the network, including those difficult to scan, corporate owned, brought by employees, and rogue IT. The data is sent immediately to the Qualys Cloud Platform for centralized analysis.
Qualys Network Passive Sensor Getting Started Guide
Reference - CAR-2013-04-002: Quick execution of a series of suspicious commands - MITRE
Certain commands are frequently used by malicious actors and infrequently used by normal users. By looking for execution of these commands in short periods of time, we can not only see when a malicious user was on the system but also get an idea of what they were doing.
CAR-2013-04-002: Quick execution of a series of suspicious commands
Reference - CAR-2013-07-002: RDP Connection Detection - MITRE
The Remote Desktop Protocol (RDP), built in to Microsoft operating systems, allows a user to remotely log in to the desktop of another host. It allows for interactive access of the running windows, and forwards key presses, mouse clicks, etc. Network administrators, power users, and end-users may use RDP for day-to-day operations. From an adversary's perspective, RDP provides a means to laterally move to a new host. Determining which RDP connections correspond to adversary activity can be a difficult problem in highly dynamic environments, but will be useful in identifying the scope of a compromise.
CAR-2013-07-002: RDP Connection Detection
Reference - RFC 2289 - A One-Time Password System
Reference - An Architecture for Describing Simple Network Management Protocol (SNMP) Management Frameworks
An Architecture for Describing Simple Network Management Protocol (SNMP) Management Frameworks
Reference - RFC 7208: Sender Policy Framework (SPF) for Authorizing Use of Domains in Email - IETF
Email on the Internet can be forged in a number of ways. In particular, existing protocols place no restriction on what a sending host can use as the "MAIL FROM" of a message or the domain given on the SMTP HELO/EHLO commands. This document describes version 1 of the Sender Policy Framework (SPF) protocol, whereby Administrative Management Domains (ADMDs) can explicitly authorize the hosts that are allowed to use their domain names, and a receiving host can check such authorization.
RFC 7208: Sender Policy Framework (SPF) for Authorizing Use of Domains in Email
Reference - RFC 7489: Domain-based Message Authentication, Reporting, and Conformance (DMARC) - IETF
Domain-based Message Authentication, Reporting, and Conformance(DMARC) is a scalable mechanism by which a mail-originating organization can express domain-level policies and preferences for message validation, disposition, and reporting, that a mail-receiving organization can use to improve mail handling. Originators of Internet Mail need to be able to associate reliable and authenticated domain identifiers with messages, communicate policies about messages that use those identifiers, and report about mail using those identifiers. These abilities have several benefits: Receivers can provide feedback to Domain Owners about the use of their domains; this feedback can provide valuable insight about the management of internal operations and the presence of external domain name abuse. DMARC does not produce or encourage elevated delivery privilege of authenticated email. DMARC is a mechanism for policy distribution that enables increasingly strict handling of messages that fail authentication checks, ranging from no action, through altered delivery, up to message rejection.
RFC 7489: Domain-based Message Authentication, Reporting, and Conformance (DMARC)
Reference - RFC 7642: System for Cross-domain Identity Management: Definitions, Overview, Concepts, and Requirements
The System for Cross-domain Identity Management (SCIM) specification is designed to manage user identity in cloud-based applications and services in a standardized way to enable interoperability, security, and scalability. The specification suite seeks to build upon experience with existing schemas and deployments, placing specific emphasis on simplicity of development and integration, while applying existing authentication, authorization, and privacy models. The intent of the SCIM specification is to reduce the cost and complexity of user management operations by providing a common user schema and extension model, as well as binding documents to provide patterns for exchanging this schema using standard protocols. In essence, make it fast, cheap, and easy to move users in to, out of, and around the cloud.
K. LI, B. Khasnabish, A. Nadalin, Z. Zeltsan
RFC7642: System for Cross-domain Identity Management: Definitions, Overview, Concepts, and Requirements
Reference - RPC call interception - Crowdstrike Inc
A service proxy is described herein. The service proxy is configured to act as an intermediary between a client and a service. The service proxy may observe communications, modify communications, log communications, or the like, particularly so as to enhance the security and reliability of the host device. In some implementations, the service proxy may cooperate with an operating system to take over a named port object. In some implementations, the service proxy may receive messages as an intermediary between the client and the server. In some implementations, the service proxy may attach to a shared memory to intercept communications. In some implementations, the service proxy may be injected into a client process to appear to be the client itself.
Reference - Red Hat Enterprise Linux 8 Security Technical Implementation Guide
Red Hat Enterprise Linux 8 Security Guidelines
Red Hat Enterprise Linux 8 Security Technical Implementation Guide
Reference - CAR-2013-03-001: Reg.exe called from Command Shell - MITRE
Registry modifications are often essential in establishing persistence via known Windows mechanisms. Many legitimate modifications are done graphically via regedit.exe or by using the corresponding channels, or even calling the Registry APIs directly. The built-in utility reg.exe provides a command-line interface to the registry, so that queries and modifications can be performed from a shell, such as cmd.exe. When a user is responsible for these actions, the parent of cmd.exe will likely be explorer.exe. Occasionally, power users and administrators write scripts that do this behavior as well, but likely from a different process tree. These background scripts must be learned so they can be tuned out accordingly.
CAR-2013-03-001: Reg.exe called from Command Shell
Reference - Registry Key Security and Access Rights
The Windows security model enables you to control access to registry keys. For more information about security, see Access-Control Model.
Reference - CAR-2016-04-005: Remote Desktop Logon - MITRE
A remote desktop logon, through RDP, may be typical of a system administrator or IT support, but only from select workstations. Monitoring remote desktop logons and comparing to known/approved originating systems can detect lateral movement of an adversary.
Reference - CAR-2014-11-005: Remote Registry - MITRE
An adversary can remotely manipulate the registry of another machine if the RemoteRegistry service is enabled and valid credentials are obtained. While the registry is remotely accessed, it can be used to prepare a Lateral Movement technique, discover the configuration of a host, achieve Persistence, or anything that aids an adversary in achieving the mission. Like most ATT&CK techniques, this behavior can be used legitimately, and the reliability of an analytic depends on the proper identification of the pre-existing legitimate behaviors. Although this behavior is disabled in many Windows configurations, it is possible to remotely enable the RemoteRegistry service, which can be detected with CAR-2014-03-005. Remote access to the registry can be achieved via * Windows API function RegConnectRegistry * command line via reg.exe * graphically via regedit.exe All of these behaviors call into the Windows API, which uses the NamedPipe WINREG over SMB to handle the protocol information. This network can be decoded with wireshark or a similar sensor, and can also be detected by hooking the API function.
Reference - CAR-2014-03-005: Remotely Launched Executables via Services - MITRE
There are several ways to cause code to execute on a remote host. One of the most common methods is via the Windows Service Control Manager (SCM), which allows authorized users to remotely create and modify services. Several tools, such as PsExec, use this functionality. When a client remotely communicates with the Service Control Manager, there are two observable behaviors. First, the client connects to the RPC Endpoint Mapper over 135/tcp. This handles authentication, and tells the client what port the endpoint--in this case the SCM--is listening on. Then, the client connects directly to the listening port on services.exe. If the request is to start an existing service with a known command line, the the SCM process will run the corresponding command. This compound behavior can be detected by looking for services.exe receiving a network connection and immediately spawning a child process.
CAR-2014-03-005: Remotely Launched Executables via Services
Reference - CAR-2015-04-002: Remotely Scheduled Tasks via Schtasks - MITRE
An adversary can move laterally using the schtasks command to remotely schedule tasks. Although these events can be detected with command line analytics CAR-2013-08-001, it is possible for an adversary to use the API directly, via the Task Scheduler GUI or with a scripting language such as PowerShell. In this cases, an additional source of data becomes necessary to detect adversarial behavior. When scheduled tasks are created remotely, Windows uses RPC (135/tcp) to communicate with the Task Scheduler on the remote machine. Once an RPC connection is established (CAR-2014-05-001), the client communicates with the Scheduled Tasks endpoint, which runs within the service group netsvcs. With packet capture and the right packet decoders or byte-stream based signatures, remote invocations of these functions can be identified. Certain strings can be identifiers of the schtasks, by looking up the interface UUID of ITaskSchedulerService in different formats * UUID 86d35949-83c9-4044-b424-db363231fd0c (decoded) * Hex 49 59 d3 86 c9 83 44 40 b4 24 db 36 32 31 fd 0c (raw) * ASCII IYD@$621 (printable bytes only) This identifier is present three times during the RPC request phase. Any sensor that has access to the byte code as raw, decoded, or ASCII could implement this analytic.
CAR-2015-04-002: Remotely Scheduled Tasks via Schtasks
Reference - Reputation of an entity associated with a content item
Reputation of an entity associated with a content item
Reference - Revoke a previously issued verifiable credential - Microsoft
Barclay Neira, Christer Ljung, Juan Camilo Ruiz, John Flores
Revoke a previously issued verifiable credential
Reference - CAR-2014-03-006: RunDLL32.exe monitoring - MITRE
Adversaries may find it necessary to use Dyanamic-link Libraries (DLLs) to evade defenses. One way these DLLs can be "executed" is through the use of the built-in Windows utility RunDLL32, which allows a user to execute code in a DLL, providing the name and optional arguments to an exported entry point. Windows uses RunDll32 legitimately in its normal operation, but with a proper baseline and understanding of the environment, monitoring its usage could be fruitful.
CAR-2014-03-006: RunDLL32.exe monitoring
Reference - /SAFESEH (Image has Safe Exception Handlers) - Microsoft Docs
When /SAFESEH is specified, the linker will only produce an image if it can also produce a table of the image's safe exception handlers. This table specifies for the operating system which exception handlers are valid for the image.
Mike Blome, Saisang Cai, Colin Robertson, Mike Jones, NextTurn, Gordon Hogenson
/SAFESEH (Image has Safe Exception Handlers)
Reference - CAR-2013-05-005: SMB Copy and Execution - MITRE
An adversary needs to gain access to other hosts to move throughout an environment. In many cases, this is a twofold process. First, a file is remotely written to a host via an SMB share (detected by CAR-2013-05-003). Then, a variety of Execution techniques can be used to remotely establish execution of the file or script. To detect this behavior, look for files that are written to a host over SMB and then later run directly as a process or in the command line arguments. SMB File Writes and Remote Execution may happen normally in an environment, but the combination of the two behaviors is less frequent and more likely to indicate adversarial activity. This can possibly extend to more copy protocols in order to widen its reach, or it could be tuned more finely to focus on specific program run locations (e.g. %SYSTEMROOT%\system32) to gain a higher detection rate.
Reference - CAR-2013-01-003: SMB Events Monitoring - MITRE
Server Message Block (SMB) is used by Windows to allow for file, pipe, and printer sharing over port 445/tcp. It allows for enumerating, and reading from and writing to file shares for a remote computer. Although it is heavily used by Windows servers for legitimate purposes and by users for file and printer sharing, many adversaries also use SMB to achieve Lateral Movement. Looking at this activity more closely to obtain an adequate sense of situational awareness may make it possible to detect adversaries moving between hosts in a way that deviates from normal activity. Because SMB traffic is heavy in many environments, this analytic may be difficult to turn into something that can be used to quickly detect an APT. In some cases, it may make more sense to run this analytic in a forensic fashion. Looking through and filtering its output after an intrusion has been discovered may be helpful in identifying the scope of compromise. Output Description: The source, destination, content, and time of each event.
Reference - CAR-2013-05-003: SMB Write Request - MITRE
As described in CAR-2013-01-003, SMB provides a means of remotely managing a file system. Adversaries often use SMB to move laterally to a host. SMB is commonly used to upload files. It may be used for staging in Exfiltration or as a Lateral Movement technique. Unlike SMB Reads, SMB Write requests typically require an additional level of access, resulting in less activity. Focusing on SMB Write activity narrows the field to find techniques that actively change remote hosts, instead of passively reading files.
Reference - SNMP - Network Auto-Discovery
SNMP, or Simple Network Management Protocol, is a protocol and a standard that is supported by just about any managed network-connected hardware. There are three widely deployed versions: SNMP v1, v2c (most commonly used), and v3. SNMP is typically utilized read-only, but supports read/write, and by default utilized port 161. SNMP exposes management data in the form of ‘variables’, which are organized in what is known as a MIB, or “Management Information Base”. A MIB essentially describes the variables available on a given system, each of which can be remotely queried via SNMP.
Reference - Secure caching of server credentials - Dell Products LP
A credential caching system includes receiving a set of authentication credentials, storing the set of authentication credentials in a credential cache memory, wherein the credential cache memory is coupled with a management controller, and supplying the set of authentication credentials for automatic authentication during a reset or reboot. In the event of a security breach, the credential caching system clears the set of authentication credentials from the credential cache memory so that the set of authentication credentials may no longer be used for a reset or reboot.
Muhammed K. JaberMukund P. KhatriKevin T. MarksDon Charles McCall
Reference - Security Architecture for the Internet Protocol
This memo describes the security mechanisms for IP version 4 (IPv4) and IP version 6 (IPv6) and the services that they provide. Each security mechanism is specified in a separate document. This document also describes key management requirements for systems implementing those security mechanisms. This document is not an overall Security Architecture for the Internet and is instead focused on IP-layer security.
Security Architecture for the Internet Protocol
Reference - Security System with Methodology for Interprocess Communication Control - Check Point Software Tech Inc
A security system with methodology for interprocess communication control is described. In one embodiment, a method for controlling interprocess communication is provided that includes steps of: defining rules indicating which system services a given application can invoke; trapping an attempt by a particular application to invoke a particular system service; identifying the particular application that is attempting to invoke the particular system service; and based on identity of the particular application and on the rules indicating which system services a given application can invoke, blocking the attempt when the rules indicate that the particular application cannot invoke the particular system service.
This patent describes a technique for monitoring interprocess communications to prevent malicious applications from requesting system services. API calls are monitored to detect malicious applications attempting to open a communication channel (port) to access system services or sending messages to other applications using user32 API functions. These requests are examined against an external rules engine or whitelist, matches deny or block access and produce an error message such as connection refused or service not available.
Security System with Methodology for Interprocess Communication Control
Reference - Security vulnerability information aggregation
Security vulnerability information aggregation techniques are disclosed. Vulnerability information associated with one or more security vulnerabilities is obtained from multiple sources and aggregated into respective unified vulnerability definitions for the one or more security vulnerabilities. Aggregation may involve format conversion, content aggregation, or both in some embodiments. Unified vulnerability definitions may be distributed to vulnerability information consumers in accordance with consumer-specific policies. Storage of vulnerability information received from the sources may allow the aggregation process to be performed on existing vulnerability information “retro-actively”. Related data structures and Graphical User Interfaces (GUIs) are also disclosed.
Christophe Gustave, Stanley Taihai Chow, Douglas Wiemer
Security vulnerability information aggregation
Reference - CAR-2014-02-001: Service Binary Modifications - MITRE
Adversaries may modify the binary file for an existing service to achieve Persistence while potentially evading defenses. If a newly created or modified runs as a service, it may indicate APT activity. However, services are frequently installed by legitimate software. A well-tuned baseline is essential to differentiating between benign and malicious service modifications.
CAR-2014-02-001: Service Binary Modifications
Reference - CAR-2013-09-005: Service Outlier Executables - MITRE
New executables that are started as a service are suspicious. This analytic looks for anomalous service executables.
CAR-2013-09-005: Service Outlier Executables
Reference - CAR-2014-07-001: Service Search Path Interception - MITRE
According to ATT&CK, an adversary may escalate privileges by intercepting the search path for legitimately installed services. As a result, Windows will launch the target executable instead of the desired binary and command line. This can be done when there are spaces in the binary path and the path is unquoted. Search path interception should never happen legitimately and will likely be the result of an adversary abusing a system misconfiguration. With a few regular expressions, it is possible to identify the execution of services with intercepted search paths.
CAR-2014-07-001: Service Search Path Interception
Reference - CAR-2014-05-002: Services launching Cmd - MITRE
Windows runs the Service Control Manager (SCM) within the process services.exe. Windows launches services as independent processes or DLL loads within a svchost.exe group. To be a legitimate service, a process (or DLL) must have the appropriate service entry point SvcMain. If an application does not have the entry point, then it will timeout (default is 30 seconds) and the process will be killed. To survive the timeout, adversaries and red teams can create services that direct to cmd.exe with the flag /c, followed by the desired command. The /c flag causes the command shell to run a command and immediately exit. As a result, the desired program will remain running and it will report an error starting the service. This analytic will catch that command prompt instance that is used to launch the actual malicious executable. Additionally, the children and descendants of services.exe will run as a SYSTEM user by default. Thus, services are a convenient way for an adversary to gain Persistence and Privilege Escalation.
Reference - CAR-2013-02-008: Simultaneous Logins on a Host - MITRE
Multiple users logged into a single machine at the same time, or even within the same hour, do not typically occur in networks we have observed. Logon events are Windows Event Code 4624 for Windows Vista and above, 518 for pre-Vista. Logoff events are 4634 for Windows Vista and above, 538 for pre-Vista. Logon types 2, 3, 9 and 10 are of interest. For more details see the Logon Types table on Microsoft's Audit Logon Events page.
CAR-2013-02-008: Simultaneous Logins on a Host
Reference - Sinkholing bad network domains by registering the bad network domains on the internet - Palo Alto Networks Inc
Techniques for sinkholing bad network domains by registering the bad network domains on the Internet are provided. In some embodiments, sinkholing bad network domains by registering the bad network domains on the Internet includes determining a network domain is a bad network domain, in which the bad network domain is determined to be associated with an identified malware (e.g., malware that has been identified and has been determined to be associated with the bad domain), and the bad network domain is sinkholed by registering the bad network domain with a sinkholed IP address; and identifying a host that is infected with the identified malware based on an attempt by the host to connect to the sinkholed IP address.
This patent describes a technique to identify bad domains that are associated with malware and sinkhole the bad domain. Bad domains are identified by receiving malware samples and executing the malware sample in a virtual execution environment to identify network domains that the malware sample attempts to connect to during execution. Network domains that are identified during malware execution are then generated into signatures to identity bad domains for other hosts. Once identified, the bad domains are sinkholed by translating the domain to a valid IP address that is associated with a device controlled by a cloud security provider.
Sinkholing bad network domains by registering the bad network domains on the internet
Reference - CAR-2019-04-003: Squiblydoo - MITRE
Squiblydoo is a specific usage of regsvr32.dll to load a COM scriptlet directly from the internet and execute it in a way that bypasses application whitelisting. It can be seen by looking for regsvr32.exe executions that load the scrobj.dll (which execute the COM scriptlet) or, if that is too noisy, those that also load content directly via HTTP or HTTPS.
Reference - Security Technologies: Stack Smashing Protection (StackGuard) - Red Hat
In our previous blog, we saw how arbitrary code execution resulting from stack-buffer overflows can be partly mitigated by marking segments of memory as non-executable, a technology known as Execshield. However stack-buffer overflow exploits can still effectively overwrite the function return address, which leads to several interesting exploitation techniques like ret2libc, ret2gets, and ret2plt. With all of these methods, the function return address is overwritten and attacker controlled code is executed when the program control transfers to overwritten address on the stack.
Security Technologies: Stack Smashing Protection (StackGuard)
This is a utility that uses supervised machine learning to detect phishing domains from the Certificate Transparency log network.
Reference - Supply chain cyber-deception - Cymmetria, Inc.
A computer implemented method of detecting unauthorized access to a protected network from external endpoints, comprising monitoring, at a protected network, communication with one or more external endpoints using one or more access clients to access one or more of a plurality of resources of the protected networked, where one or more deception resources created in the protected network map one or more of the plurality of resources, detecting usage of data contained in one or more of a plurality of deception data objects deployed in the one or more access clients by monitoring an interaction triggered by one or more of the deception data objects with the one or more deception resources when used and identifying one or more potential unauthorized operations based on analysis of the detection.
Gadi EVRON; Dean SYSMAN; Imri Goldberg; Shmuel Ur
Reference - CAR-2013-07-001: Suspicious Arguments - MITRE
Malicious actors may rename built-in commands or external tools, such as those provided by SysInternals, to better blend in with the environment. In those cases, the file path name is arbitrary and may blend in well with the background. If the arguments are closely inspected, it may be possible to infer what tools are running and understand what an adversary is doing. When any legitimate software shares the same command lines, it must be whitelisted according to the expected parameters.
Reference - CAR-2013-05-002: Suspicious Run Locations - MITRE
In Windows, files should never execute out of certain directory locations. Any of these locations may exist for a variety of reasons, and executables may be present in the directory but should not execute. As a result, some defenders make the mistake of ignoring these directories and assuming that a process will never run from one. There are known TTPs that have taken advantage of this fact to go undetected. This fact should inform defenders to monitor these directories more closely, knowing that they should never contain running processes.
CAR-2013-05-002: Suspicious Run Locations
Reference - Synchronizing a honey network configuration to reflect a target network environment - Palo Alto Networks Inc
Techniques for synchronizing a honey network configuration to reflect a target network environment are disclosed. In some embodiments, a system for synchronizing a honey network configuration to reflect a target network environment includes a device profile data store that includes a plurality of attributes of each of a plurality of devices in the target network environment; a virtual machine (VM) image library that includes one or more VM images; and a virtual clone manager executed on a processor that instantiates a virtual clone of one or more devices in the target enterprise network using a VM image selected from the VM image library that is customized based on one or more attributes for a target device in the device profile data store.
Synchronizing a honey network configuration to reflect a target network environment
Reference - System and a method for identifying the presence of malware and ransomware using mini-traps set at network endpoints - Fidelis Cybersecurity Solutions Inc
A system for identifying the presence of ransomware on a network, including a plurality of resources, interconnected to form a network and at least one decoy drive.The decoy drive includes a plurality of decoy files to be encrypted by the ransomware, and wherein the decoy drive continuously provides the decoy files thereby continuously occupying the ransomware.
Doron Kolton; Rami Mizrahi; Omer Zohar; Benny Ben-Rabi; Alex Barbalat; Shlomi Gabai
System and a method for identifying the presence of malware and ransomware using mini-traps set at network endpoints
Reference - System and method for detecting homoglyph attacks with a siamese convolutional neural network - Endgame Inc
The present invention utilizes computer vision technologies to identify potentially malicious URLs and executable files in a computing device. In one embodiment, a Siamese convolutional neural network is trained to identify the relative similarity between image versions of two strings of text. After the training process, a list of strings that are likely to be utilized in malicious attacks are provided (e.g., legitimate URLs for popular websites). When a new string is received, it is converted to an image and then compared against the image of list of strings. The relative similarity is determined, and if the similarity rating falls below a predetermined threshold, an alert is generated indicating that the string is potentially malicious.
Jonathan Woodbridge; Anjum Ahuja; Daniel Grant
This patent describes a mechanism to detect homoglyph strings that involves training a Siamese convolutional neural network to compare images of strings. Strings of legitimate URLs for websites along with known suspicious stings are converted to images during the training process to create an index. New strings are converted to images and then compared to the index for similarity, if the string deviates beyond a threshold an alert is triggered.
System and method for detecting homoglyph attacks with a siamese convolutional neural network
Reference - System and method for detecting malware injected into memory of a computing device - Endgame Inc
In the embodiments described herein, a malicious code detection module identifies potentially malicious instructions in memory of a computing device. The malicious code detection module examines the call stack for each thread running within the operating system of the computing device. Within each call stack, the malicious code detection module identifies the originating module for each stack frame and determines whether the originating module is backed by an image on disk. If an originating module is not backed by an image on disk, the thread containing that originating module is flagged as potentially malicious, execution of the thread optionally is suspended, and an alert is generated for the user or administrator.
System and method for detecting malware injected into memory of a computing device
Reference - System and Method for Detection of a Change in Behavior in the Use of a Website Through Vector Velocity Analysis - Silver Tail Systems
A system and software for identifying the change of user behavior on a website includes analyzing the actions of users on a website comprising a plurality of fields or input parameters that identify the actions performed on a website including fields related to previous actions by that user or other users of the website. The fields or input parameters are represented in a vector format where vectors represent different sessions of activity on the website, pages of the website, users of the website, or other attributes of the use of a website. Analysis is performed to determine if new sessions are similar or dissimilar to previously known sessions and if a session is converging or diverging from known sessions based on the velocity and direction of the velocity of the vectors in the vector space.
Mike Eynon; Laura Mather; Erik Westland; Jim Lloyd
This patent describes a technique for detecting fraudulent behavior on a website. Website behavior is mapped to build a multidimensional representation of user actions on a website that is updated as additional actions are recorded. Example actions on a website that are recorded include clicks by a user on the website and entering data into forms. Current behavior is compared against baseline recorded behavior and if current behavior deviates above a threshold, an alert is issued.
System and Method for Detection of a Change in Behavior in the Use of a Website Through Vector Velocity Analysis
Reference - System and method for internet security - Cylance Inc
A computer implemented method for preventing SQL injection attacks comprises intercepting a web request associated with a web service at a first software hook in a first web service execution context, persisting at least a portion of the intercepted web request in a storage location associated with the first software hook and accessible to at least one additional execution context, intercepting a database query generated by at least one web service processing operation at a second software hook associated with the execution of the query, wherein the query is generated in response to the intercepted web request and the second hook retrieves the persisted portion of the intercepted web request, comparing a portion of the persisted portion of the intercepted web request with at least a portion of the intercepted database query, and determining, prior to the query being executed, whether the query corresponds to a potential SQL injection attack.
This patent describes a technique for detecting SQL injection attacks. Software hooks are installed in a web service or application to intercept function calls, events, or messages that are passed between software components. Intercepted database queries associated with a web request are analyzed character by character and if it contains a character that would modify the syntax the query is rejected or sanitized. Security rules and policies may also determine rejection. For example, an administrator or developer may implement a rule that rejects any database query that is excessively long or that contains a particular string, such as "Xp cmdshell".
Reference - System and Method for Network Security Including Detection of Attacks Through Partner Websites - EMC IP Holding Co LLC
A computer readable storage medium has instructions for execution on a computer. The instructions monitor transactions between a server and a set of clients. An evaluation of session indicators associated with the transactions is performed. Individual sessions between the server and individual clients of the plurality of clients are isolated in response to the evaluation.
Matt Frantz; Andreas Wittenstein; Mike Eynon; Laura Mather; Jim Lloyd; James Schumacher; Duane Murphy
This patent describes a technique for detecting man-in-the-browser attacks. Current user session data is compared with the average user session that is based on collected data representing average values across all user sessions over a data-collection period. User session data includes average time between clicks and the order in which website pages are viewed. The comparisons are combined to generate a score that indicates the likelihood that the current session is a man-in-the-browser attack.
System and Method for Network Security Including Detection of Attacks Through Partner Websites
Reference - System and Method for Process Hollowing Detection - Carbon Black Inc
A method and system for remediating a process hollowing intrusion on a user device comprising detecting a process starting on the user device, preparing the process to monitor Application Programming Interface (API) calls between the process and an operating system of the user device, determining whether the process is associated with a process hollowing intrusion based on information associated with the process and/or the API calls, and executing security policies against the process associated with the process hollowing intrusion. In examples, it is determined whether the child process is associated with a process hollowing intrusion in response to determining whether one or more API calls associated with known process hollowing intrusions modify executable memory of and/or modify an entry point address of the child process.
Jeffrey Albin Kraemer, Paul Matthew Drapeau
System and Method for Process Hollowing Detection
Reference - System and method for providing an actively invalidated client-side network resource cache - IMVU
A system and method for providing an actively invalidated client-side network resource cache are disclosed. A particular embodiment includes: a client configured to request, for a client application, data associated with an identifier from a server; the server configured to provide the data associated with the identifier and to establish a queue associated with the identifier at a scalable message queuing system, the client being configured to subscribe to the queue at the scalable message queuing system to receive invalidation information associated with the data; the server being further configured to signal the queue of an invalidation event associated with the data; the scalable message queuing system being configured to convey information indicative of the invalidation event to the client; and the client being further configured to re-request the data associated with the identifier from the server upon receipt of the information indicative of the invalidation event.
System and method for providing an actively invalidated client-side network resource cache
Reference - System and method for providing anonymous remailing and filtering of electronic mail - Nokia
To make anonymous a sender name present on an actual transmission source address by including an alias transmission source address substitution unit and removing the actual transmission source address from an electronic mail message. SOLUTION: A hash value of the destination address of an electronic mail message is calculated (S330). Then, (n) blank bytes are added to a compressed actual transmission source address (S340). The true length of the actual transmission source address is hidden by adding blank bytes. Further, a 2nd bit field is added to a secret key saved locally in a remailer, and an extended secret key characteristic of the destination address is generated. Then, the compressed actual transmission source address is ciphered according to the data ciphering standards using the extended secret key characteristic of the destination address as a cipher key (S350). Further, the 2nd bit field is added to the ciphered and compressed actual transmission source address (S360).
Eran Gabber, Phillip B Gibbons, David Morris Kristol, Yossi Matias, Alain J Mayer
System and method for providing anonymous remailing and filtering of electronic mail
Reference - System and method for scanning remote services to locate stored objects with malware
A system and method for retrieval and analysis of stored objects for malware is described. The method involves receiving a scan request message from a customer to conduct analytics on one or more objects stored within a third-party controlled service. In response to receipt of the scan request message, the system generates a redirect message. The redirect message redirects the customer to an authentication portal of the third-party controlled service operating as a logon page and configures receipt by the system of access credentials for the third-party controlled service upon verification of the customer. Using the access credentials, the system is able to retrieve the one or more objects using the access credentials and performing analytics on each object of the one or more objects to classify each object as malicious or benign.
Mandiant Inc, FireEye Security Holdings US LLC
System and method for scanning remote services to locate stored objects with malware
Reference - System and method for validating in-memory integrity of executable files to identify malicious activity - Endgame Inc
In the embodiments described herein, a malicious code detection module identifies potentially malicious instructions in volatile memory of a computing device before the instructions are executed. The malicious code detection module identifies an executable file, such as an .exe file, in memory, validates one or more components of the executable file against the same file stored in non-volatile storage, and issues an alert if the validation fails.
System and method for validating in-memory integrity of executable files to identify malicious activity
Reference - System and method for vulnerability risk analysis
Embodiments of the present invention are directed to a method and system for automated risk analysis. The method includes accessing host configuration information of a host and querying a vulnerability database based on the host configuration information. The method further includes receiving a list of vulnerabilities and accessing a plurality of vulnerability scores. The list of vulnerabilities corresponds to vulnerabilities of the host. Vulnerabilities can be removed from the list based on checking for installed fixes corresponding to vulnerability. A composite risk score can then be determined for the host a nd each software product of the host based on the plurality of vulnerability scores. An aggregate risk score can then be determined for the host and each software product of the host based on the plurality of vulnerability scores.
Matthew Cruz Elder, Darrell Martin Kienzle, Pratyusa K. Manadhata, Ryan Kumar Persaud
System and method for vulnerability risk analysis
Reference - System and methods thereof for causality identification and attributions determination of processes in a network - Palo Alto Networks IncCyber Secdo Ltd
This patent describes detecting malicious processes on a host. Agents are deployed on hosts that monitor all initiated processes and determine whether a process was initiated at boot or initiated by another process. If not initiated at boot or by another process, the process is identified as suspicious and an alert is triggered.
System and methods thereof for causality identification and attributions determination of processes in a network
Reference - System and methods thereof for identification of suspicious system processes - Palo Alto Networks Inc
A computerized method for identification of suspicious processes executing on an end-point device communicatively connected to network, the network communicatively connected to a server, the method comprising receiving, by the server, a record of at least one process, initiated by and executing on by the end-point device. One or more parameters associated with the at least one process are identified. A first time pointer is identified corresponding to the identified one or more parameters, a first time pointer. A second time pointer at which a user associated with the end-point device initiated a user dependent process is identified. Whether the second time pointer occurred before the first time pointer is identified. It is determined whether the at least one process was initiated by the user based on identification of user dependent processes and corresponding attribution. An action is performed based on the above determination.
The patent describes detecting malicious processes by identifying the order of process initiation. The start of a user initiated process (user query, opening an application, etc.) is compared with the start of processes initiated by the device (ex. during boot). In addition, a determination is made on whether processes are not initiated by a user by examining process parameters such as type of process, its creator, source, etc. If it is determined that a user initiated process was started before a process initiated by the device and a process was not initiated by the user, the process is marked as suspicious.
System and methods thereof for identification of suspicious system processes
Reference - System and methods thereof for logical identification of malicious threats across a plurality of end-point devices (epd) communicatively connected by a network - Palo Alto Networks IncCyber Secdo Ltd
A computerized method for logical identification of malicious threats across a plurality of end-point devices (EPD) communicatively connected by a network, comprising collecting over the network an identifier associated with each file of a plurality of files, wherein each file of the plurality of files is installed on at least one of the plurality of EPDs and wherein the identifier is the same for each like file of the plurality of file. Information associated with an identified subset of files is collected, wherein the information indicates at least a time at which the at least one file was installed on one or more of the plurality of EPDs and the way the at least one file spread within the network. The collected information is analyzed according to a set of predetermined computerized investigation rules. The analysis is used to determine whether at least a file of the identified subset files is a suspicious file.
This patent describes detecting suspicious files using file metadata such as the prevalence of the file deployed on the network, file installation times, and how the file was spread within the network. The combination of these factors are used to determine a risk score of the file and if below a threshold, sends an alert.
System and methods thereof for logical identification of malicious threats across a plurality of end-point devices (epd) communicatively connected by a network
Reference - System and methods thereof for preventing ransomware from encrypting data elements stored in a memory of a computer-based system - Palo Alto Networks Inc
A computerized method for preventing ransomware from encrypting data elements stored in a memory of a computer-based system, the method comprising identifying at least one identifier for a data element, wherein the at least one identifier indicates at least a position of the data element within the memory. An optimal number of virtual traps is determined for the data element corresponding to the at least one identifier. An optimal position for each of the virtual traps is determined corresponding to the at least one identifier. The virtual traps are send to the determined optimal position within the memory.
System and methods thereof for preventing ransomware from encrypting data elements stored in a memory of a computer-based system
Reference - System for detecting threats using scenario-based tracking of internal and external network traffic - VECTRA NETWORKS Inc
Disclosed is an improved approach to implement a system and method for detecting insider threats, where models are constructed that is capable of defining what constitutes the normal behavior for any given hosts and quickly find anomalous behaviors that could constitute a potential threat to an organization. The disclosed approach provides a way to identify abnormal data transfers within and external to an organization without the need for individual monitoring software on each host, by leveraging metadata that describe the data exchange patterns observed in the network.
Determination of anomalous data transfers is performed over a given time period. For example, a check of a pull vs. push data ratio can be established over a specific time period, e.g., over a three-hour period, over a one day period, over a one week period, etc. The system can also establish a baseline behavior for data exchange for each host in terms of pull vs. push data ratio for each resource contacted by the host. Network packet capture data is collected and metadata is extracted. Aggregate data push/pull information from the metadata is then analyzed for a given host versus specific client to server relationships. This technique can potentially catch lateral data transfers, and may have filtering on alerting logic to only raise alarms when external hosts receive large data transfers.
System for detecting threats using scenario-based tracking of internal and external network traffic
Reference - System for implementing threat detection using threat and risk assessment of asset-actor interactions - VECTRA NETWORKS Inc
Disclosed is an approach to detect insider threats, by tracking unusual access activity for a specific user or computer with regard to accessing key assets over time. In this way, malicious activity and the different preparation phases of attacks can be identified.
Himanshu Mhatre; David Lopes Pegna; Oliver Brdiczka
The patent describes an insider threat detection system that analyzes packets sent within a network to identify and isolate malicious behavior. Current network traffic is collected and developed into a baseline that establishes the amount of data sent and received between a specific asset and a host. Current data transfer values are then compared with the baseline to identify anomalies.
System for implementing threat detection using threat and risk assessment of asset-actor interactions
Reference - Systems and methods for detecting credential theft - Symantec Corp
The disclosed computer-implemented method for detecting credential theft may include (i) monitoring a secured computing system's credential store that may include at least one sensitive credential that may be used to facilitate authentication of a user that is attempting to access the secured computing system, (ii) gathering, while monitoring the credential store, primary evidence of an attempted theft of the sensitive credential from the credential store, (iii) gathering corroborating evidence of the attempted theft of the sensitive credential, and (iv) performing a security action in response to gathering the primary evidence and the corroborating evidence of the attempted theft. The primary evidence of the attempted theft of the sensitive credential may include evidence of any suspicious access of the sensitive credential from the credential store that occurs outside of a procedure of authenticating the user. Various other methods, systems, and computer-readable media are also disclosed.
Adam Glick; Brian Schlatter; Feng Li; Akshata Krishnamoorthy Rao
Systems and methods for detecting credential theft
Reference - TCG Trusted Attestation Protocol Use Cases for TPM Families 1.2 and 2.0 and DICE
TCG Trusted Attestation Protocol Use Cases for TPM Families 1.2 and 2.0 and DICE
Reference - TPM 2.0 Library Specification - Trusted Computing Group, Incorporated
This specification defines the Trusted Platform Module (TPM) a device that enables trust in computing platforms in general. It is broken into parts to make the role of each part clear. All parts are required in order to constitute a complete standard. For a complete definition of all requirements necessary to build a TPM, the designer will need to use the appropriate platform-specific specification to understand all of the requirements for a TPM in a specific application or make appropriate choices as an implementer. Those wishing to create a TPM need to be aware that this specification does not provide a complete picture of the options and commands necessary to implement a TPM. To implement a TPM the designer needs to refer to the relevant platform-specific specification to understand the options and settings required for a TPM in a specific type of platform or make appropriate choices as an implementer.
Reference - Tamper proof mutating software - ARXAN TECHNOLOGIES Inc
System and method is disclosed for protecting client software running on a client computer from tampering using a secure server. Prior to or independent of executing the client software, the system integrates self-protection into the client software; removes functions from the client software for execution on the server; develops client software self-protection updates; and periodically distributes the updates. During execution of the client software, the system receives an initial request from the client computer for execution of the removed function; verifies the initial request; and cooperates with the client computer in execution of the client software if verification is successful. If verification is unsuccessful, the system can attempt to update the client software on the client computer; and require a new initial request. Client software can be updated on occurrence of a triggering event. Communications can be encrypted, and the encryption updated. Authenticating checksums can be used for verification.
Reference - Technical Specifications for Construction and Management of Sensitive Compartmented Information Facilities
National Counterintelligence and Security Center
Technical Specifications for Construction and Management of Sensitive Compartmented Information Facilities
Reference - Tenable Passive Network Monitoring
Tenable Nessus® Network Monitor (NNM), a passive monitoring sensor, continuously discovers active assets on the network and assesses them for vulnerabilities. NNM is based on patented network discovery and vulnerability analysis technology that continuously monitors and profiles non-intrusively. It monitors IPv4, IPv6 and mixed network traffic at the packet layer to determine topology, services and vulnerabilities.
Reference - Testing Metrics for Password Creation Policies by Attacking Large Sets of Revealed Passwords
Matt Weir, Sudhir Aggarwal, Michael Collins, Henry Stern
Testing Metrics for Password Creation Policies by Attacking Large Sets of Revealed Passwords
Reference - The Pyramid of Pain - David Bianco
This article identifies progressive levels of adversary difficulty encountered for various types of indicators.
Reference - Threat detection for return oriented programming - Crowdstrike Inc
This disclosure describes, in part, techniques for detecting security exploits associated with return-oriented programming. The techniques include determining that a retrieved count is indicative of malicious activity, such as return oriented programming. The count may be retrieved from a processor performance counter of prediction mismatches, the prediction mismatches resulting from comparisons of a call stack of a computing device and of a shadow call stack maintained by a processor of the computing device. The techniques further include performing at least one security response action in response to determining that the count indicates malicious activity.
This patent describes a technique for detecting shellcode security exploits. A call stack of a computing device is compared with a shadow call stack maintained by a processor of the computing device since a return oriented program may only be able to control or spoof the call stack and not the shadow call stack. Mismatches between the two are counted and if the number of mismatches exceeds a certain threshold it is an indication of malicious activity and a security response action is performed.
Threat detection for return oriented programming
Reference - Threat detection through the accumulated detection of threat characteristics - Sophos Ltd
Embodiments of the present disclosure provide for improved capabilities in the detection of malware, where malware threats are detected through the accumulated identification of threat characteristics for targeted computer objects. Methods and systems include dynamic threat detection providing a first database that correlates a plurality of threat characteristics to a threat, wherein a presence of the plurality of the threat characteristics confirms a presence of the threat; detecting a change event in a computer run-time process; testing the change event for a presence of one or more of the plurality of characteristics upon detection of the change event; storing a detection of one of the plurality of characteristics in a second database that accumulates detected characteristics for the computer run-time process; and identifying the threat when each one of the plurality of characteristics appears in the second database.
Threat detection through the accumulated detection of threat characteristics
Reference - Tokenless biometric transaction authorization method and system
A method and system for tokenless authorization of commercial transactions between a buyer and a seller using a computer system. A transaction is proposed by a seller, and the buyer signals his acceptance by entering his personal authentication information comprising a PIN and at least one biometric sample, forming a commercial transaction message. The commercial transaction message is forwarded to the computer system, where the computer system compares the personal authentication information in the commercial transaction message with previously registered buyer biometric samples. If the computer system successfully identifies the buyer, a financial account of the buyer is debited and a financial account of the seller is credited, and the results of the transaction are presented to both buyer and seller. As a result of the invention, a buyer can conduct commercial transactions without having to use any tokens such as portable man-made memory devices such as smartcards or swipe cards. The invention allows buyers to quickly select one of a group of different financial accounts from which to transfer funds. The invention further indicates to the user that the authentic computer system was accessed by the use of a private code that is returned to the buyer after the identification is complete. The invention additionally permits an authorized buyer to alert authorities in the event of an emergency, such as when a transaction is coerced.
Tokenless biometric transaction authorization method and system
Reference - Trusted Attestation Protocol Use Cases
## Document Abstract This specification defines the Trusted Platform Module (TPM) a device that enables trust in computing platforms in general. It is broken into parts to make the role of each part clear. All parts are required in order to constitute a complete standard. For a complete definition of all requirements necessary to build a TPM, the designer will need to use the appropriate platform-specific specification to understand all of the requirements for a TPM in a specific application or make appropriate choices as an implementer. Those wishing to create a TPM need to be aware that this specification does not provide a complete picture of the options and commands necessary to implement a TPM. To implement a TPM the designer needs to refer to the relevant platform-specific specification to understand the options and settings required for a TPM in a specific type of platform or make appropriate choices as an implementer.
Reference - CAR-2019-04-001: UAC Bypass - MITRE
Bypassing user account control (UAC Bypass) is generally done by piggybacking on a system process that has auto-escalate privileges. This analytic looks to detect those cases as described by the open-source UACME tool.
Reference - UEFI Platform Initialization (PI) Specification
UEFI Platform Initialization (PI) Specification
Reference - USB filter for hub malicious code prevention system
The present invention relates generally to computer systems, and more specifically, to a universal serial bus (USB) filter hub for a computer system.
Universal serial bus (USB) filter hub malicious code prevention system
Reference - Use of an application controller to monitor and control software file and application environments - Sophos Ltd
In embodiments of the present invention, a framework for an extensible, file-based security system is described for determining an appropriate application, application environment, and/or access or security control measure based at least in part on a file's reputation. In response to the selection of a file, an application controller may be used to select a software application from two or more software applications to open the selected file, based at least in part on the selected file's reputation. If launched, a software application may be configured to open the file in an environment, such as a virtual machine, quarantined environment, and the like, that is appropriate for the file based at least in part on the reputation information. A software application may be a secure software application configured to manage secure files, or an insecure software application configured to manage insecure files. The selected file, and communications relating to the selected software application, may be managed according to the selected software application's secure or insecure configuration. Further, the selected software application may associate reputation information with all files that are modified and/or created by the selected software application, including at least in part, reputation information matching that of the selected file.
This patent describes received files being open in an environment such as a virtual machine or quarantined environment to associate file reputation information that determines if a file is a threat.
Use of an application controller to monitor and control software file and application environments
Reference - CAR-2016-04-003: User Activity from Stopping Windows Defensive Services - MITRE
Spyware and malware remain a serious problem and Microsoft developed security services, Windows Defender and Windows Firewall, to combat this threat. In the event Windows Defender or Windows Firewall is turned off, administrators should correct the issue immediately to prevent the possibility of infection or further infection and investigate to determine if caused by crash or user manipulation.
CAR-2016-04-003: User Activity from Stopping Windows Defensive Services
Reference - CAR-2013-10-001: User Login Activity Monitoring - MITRE
Monitoring logon and logoff events for hosts on the network is very important for situational awareness. This information can be used as an indicator of unusual activity as well as to corroborate activity seen elsewhere. Could be applied to a number of different types of monitoring depending on what information is desired. Some use cases include monitoring for all remote connections and building login timelines for users. Logon events are Windows Event Code 4624 for Windows Vista and above, 518 for pre-Vista. Logoff events are 4634 for Windows Vista and above, 538 for pre-Vista.
CAR-2013-10-001: User Login Activity Monitoring
Reference - Using spanning tree protocol (STP) to enhance layer-2 topology maps
Spanning Tree Protocol (STP) data is obtained via network switch (SNMP) queries to enhance identification of switch-to-switch links in Layer-2 mapping. In particular, by analyzing the STP data, ambiguity in determining switch uplink ports may be reduced. Specifically, the STP data can be used in conjunction with other topography data to provide Layer-2 connectivity for nodes on a network topology. Layer-2 address mapping tables are collected from a topology mapping, and STP data is collected, along with address translation tables (ARP) tables. Using this information, switches are identified using Layer-2 address tables. The STP data can be correlated by comparing data in switches, identifying switch ports directly connected to other switch ports, and eliminating direct switch-to-switch port connections from consideration for further Layer-2 node mappings.
Using spanning tree protocol (STP) to enhance layer-2 topology maps
Reference - Virtualized process isolation - Advanced Micro Devices Inc
Systems, apparatuses, and methods for implementing virtualized process isolation are disclosed. A system includes a kernel and multiple guest VMs executing on the system's processing hardware. Each guest VM includes a vShim layer for managing kernel accesses to user space and guest accesses to kernel space. The vShim layer also maintains a separate set of page tables from the kernel page tables. In one embodiment, data in the user space is encrypted and the kernel goes through the vShim layer to access user space data. When the kernel attempts to access a user space address, the kernel exits and the vShim layer is launched to process the request. If the kernel has permission to access the address, the vShim layer copies the data to a region in kernel space and then returns execution to the kernel.
Reference - Web Authentication: An API for accessing Public Key Credentials Level 2
This specification defines an API enabling the creation and use of strong, attested, scoped, public key-based credentials by web applications, for the purpose of strongly authenticating users. Conceptually, one or more public key credentials, each scoped to a given WebAuthn Relying Party, are created by and bound to authenticators as requested by the web application. The user agent mediates access to authenticators and their public key credentials in order to preserve user privacy. Authenticators are responsible for ensuring that no operation is performed without user consent. Authenticators provide cryptographic proof of their properties to Relying Parties via attestation. This specification also describes the functional model for WebAuthn conformant authenticators, including their signature and attestation functionality.
Web Authentication: An API for accessing Public Key Credentials Level 2
What is NX/XD feature ? How to check whether NX/XD is enabled ? How to enable or disable NX/XD? NX/XD is a hardware cpu feature which is provided in almost all the hardware. Some BIOS has advanced option of enabling or disabling it. NX stands for No eXecute and XD stands for eXecute Disable. Both are same and is a technology used in processors to prevent execution of certain types of code.
Windows 10 Security Technical Implementation Guide
Reference - CAR-2014-11-006: Windows Remote Management (WinRM) - MITRE
CAR-2014-11-006: Windows Remote Management (WinRM)
Issue a new credential to a user which supercedes their old credential.
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.
Restoring a previously captured disk image a hard drive.
Restoring an email for an entity to access.
Restoring a entity's access to a computer network.
Blocking a reverse lookup based on the query's IP address value.
## 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.
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.
The goal of transductive learning is to infer the correct labels for the given unlabeled data x_{l+1},... ,x_{l+u} only
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.
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 network.[14] Additionally, in Windows 9x and later, Windows shell tries to find the target of a broken shortcut before proposing to delete it.
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.
## References Wikipedia. (n.d.). Skewness. [Link](https://en.wikipedia.org/wiki/Skewness)
The standard deviation is a measure of the amount of variation or dispersion of a set of values.
## References Wikipedia. (n.d.). Standard deviation. [Link](https://en.wikipedia.org/wiki/Standard_deviation)
A statement is a proposition that is either (a) a meaningful declarative sentence that is either true or false, or (b) that which a true or false declarative sentence asserts.
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.
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.]
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.
Adversaries may exfiltrate data, such as sensitive documents, through the use of automated processing after being gathered during Collection.(Citation: ESET Gamaredon June 2020)
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.
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)).
Trusted Developer Utilities Proxy Execution
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.
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.
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)
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.
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.
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
## References Temporal difference learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Temporal_difference_learning).
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.
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.
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.
The arithmetic mean of data values after a certain number or proportion of the highest and lowest data values have been discarded.
Stores public information necessary to determine if another party can be trusted.
Restoring a user account's access to resources by unlocking a locked User Account.
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.
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.
## References Wikipedia. (n.d.). Variance. [Link](https://en.wikipedia.org/wiki/Variance)
A request-response comprising a user credential presentation to a system and a verification response where the verifying party is a web server.
A mean that incorporates weighting to certain data elements.
## 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)
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.
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.
archived-at
x attached-to y: A subject x is joined in close association to an object y.
x attack-kb-annotation y: The offensive technique x has the kb annotation of y.
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.
x comments y: x claim has provider comments y.
The control (or control enhancement) name.
x copy-of y: The subject x is a duplicate of the object y
x d3fend-comment y: The entity x has an D3FEND team written a public note about entity y.
Unique identifier for a D3FEND technique. D3-[Acronym].
x dependent y: A dependent y is an entity that requires the fulfillment of the requirements specified in dependency x.
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.
x has-account y: The subject x has ownership or possession of some account y.
x has-link y: The d3fend analysis x has the link y.
x has-location y: The entity x is situated in a particular spot or position y.
x has_recipient y: An agent y is the intended recipient and decoder of the information contained in communication x.
x has_sender y: An agent y is the sender and encoder of the information contained in communication x.
x hides y: A technique or operation x conceals the digital artifact y.
x installs y: An entity x sets up a digital artifact y for subsequent use. For example, an installation program can install application software.
definition "x instructed-by y: A subject x takes machine instructions from object y."
definition "x instructs y: A subject x delivers machine instructions to object y."
x kb-reference-title y: The d3fend knowledge base reference x has the reference title string y.
x limits y: An entity x specifies a designated limit beyond which some entity y cannot function or must be terminated.
date modified
name
x neutralizes y: The technique x makes the execution of actions of y ineffective by preventing or counterbalancing the effect of y.
operating-system
x operating-system y: The product x is supported on operating system y.
x owns y: The subject x has ownership or possession of some object y.
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.
x process-command-line-arguments y: The process x has the process command line arguments data y.
x process-environment-variables y: The process x has the process environmental variables data y.
x process-identifier y: The process x has the process identifier y.
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.
x process-security-context y: The process x has the process security context data y.
x process-user y: The process x has been executed by the user y.
x provider y: A provider y is an entity that supplies a service, system, or data resources to a dependent entity x.
date published
x regenerates y: The entity x discards the current digital artifact y and creates a new version that serves the same function.
x summarizes y: The sensor x summarizes a set y of events concerning digital artifacts over time
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.
x updates y: The technique x updates the software for component y.
x use-limits y: An entity x specifies a designated number of uses beyond which some entity y cannot function or must be terminated.
x value y: The key-value pair x has the key y.
x value y: The key-value pair x has the data value y.
ATTACK things are concepts defined in the ATT&CK Framework.
A collection of objects that can have access controls placed on them.
Access modeling identifies and records the access permissions granted to administrators, users, groups, and systems.
Actively collecting PKI certificates by connecting to the server and downloading its server certificates for analysis.
## 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 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
## 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 sends and receives network traffic as a means to map the physical layer.
Application Configuration Database Record
A database record holding information used to configure the parameters and initial settings for an application.
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
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.
## References ANN Classification. [Link](http://uc-r.github.io/ann_classification).
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 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.
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).
The average absolute deviation (AAD) of a data set is the average of the absolute deviations from a central point.
Bayesian analysis is a statistical procedure which endeavors to estimate parameters of an underlying distribution based on the observed distribution.
## References Wolfram MathWorld. (n.d.). Bayesian Analysis. [Link](https://mathworld.wolfram.com/BayesianAnalysis.html)
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.
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.
A d3f:Record which is an essential component of the early boot (system initialization) process.
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.
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.
Exposure of Sensitive Information Through Metadata
Improper Preservation of Consistency Between Independent Representations of Shared State
Improper Validation of Specified Quantity in Input
Improper Validation of Specified Index, Position, or Offset in Input
Reliance on Component That is Not Updateable
Reliance on Insufficiently Trustworthy Component
Improper Neutralization of Leading Special Elements
Improper Neutralization of Multiple Trailing Special Elements
Improper Neutralization of Multiple Internal Special Elements
Incorrect Behavior Order: Early Validation
Improper Removal of Sensitive Information Before Storage or Transfer
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Authentication Bypass Using an Alternate Path or Channel
Missing Authentication for Critical Function
Cleartext Transmission of Sensitive Information
Transmission of Private Resources into a New Sphere ('Resource Leak')
Unintended Proxy or Intermediary ('Confused Deputy')
User Interface (UI) Misrepresentation of Critical Information
Exposure of Sensitive System Information to an Unauthorized Control Sphere
Client-Side Enforcement of Server-Side Security
Improper Isolation or Compartmentalization
Reliance on a Single Factor in a Security Decision
Use of a Non-reentrant Function in a Concurrent Context
Lack of Administrator Control over Security
Use of Multiple Resources with Duplicate Identifier
Access of Memory Location Before Start of Buffer
Incomplete Filtering of Special Elements
Incomplete Filtering of One or More Instances of Special Elements
Only Filtering Special Elements at a Specified Location
Improper Control of Interaction Frequency
XML Injection (aka Blind XPath Injection)
Improper Control of Dynamically-Identified Variables
Use of Password Hash With Insufficient Computational Effort
Insecure Storage of Sensitive Information
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.
A certificate truststore is used to store public certificates used to authenticate clients by the server for an SSL connection.
Comparing client-server request and response payloads to a baseline profile to identify outliers.
## 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.
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
http://attackguidev.mitre.org/techniques/T1554/ "Compromise Client Software Binary"
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 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.
A request-response comprising a user credential presentation to a system and a verification response where the verifying party is a cloud service.
Cloud authorization is the function of specifying access rights to cloud resources.
Cloud storage is storage held within a computing cloud.
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.
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.
A command history log file is a file containing a command history, which the history of commands run in an operating system shell.
A common attack pattern that is in the CAPEC knowledge base.
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.
The connect socket system call connects the socket to a target address.
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.
## 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.
Analyzing failed connections in a network to detect unauthorized activity.
## 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.
Analyzing a Container Image with respect to a set of policies.
## 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.
A d3f:Software which manages and coordinates running one or more d3f:ContainerProcess.
A control correlation identifier (CCI) catalog provides a catalog of CCIs for a given release date.
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.
## References Wikipedia. (n.d.). Convolutional neural network. [Link](https://en.wikipedia.org/wiki/Convolutional_neural_network)
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).
Deleting a set of credentials permanently to prevent them from being used to authenticate.
## 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.
Limiting the transmission of a credential to a scoped set of relying parties.
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.
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.
DHCP Network Traffic is network traffic related to the DHCP protocol, used by network nodes to negotiate and configure either IPv4 or IPv6 addresses.
Data inventorying identifies and records the schemas, formats, volumes, and locations of data stored and used on the organization's architecture.
Issuing publicly released media to deceive adversaries.
## 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
An authentication token created for the purposes of deceiving an adversary.
## 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.
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
## References Deep learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Deep_learning).
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.
Function with an input of serialized data which deserializes that data, usually with data parsing methods.
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.
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.
Filtering incoming email traffic based on specific criteria.
## 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
The email removal technique deletes email files from system storage.
## 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.
Equivalence matching is matching two values, which may be bound to variables, to see if they are equivalent.
## 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 represents ways or a process of learning and determining the population parameter based on the model fitted to the data.
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.
Identifying and extracting files from network application protocols through the use of network stream reassembly software.
## 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.
Analyzing the properties of file create system call invocations.
File eviction techniques evict files from system storage.
Analyzing the reputation of a file hash.
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.
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".
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.
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.
## 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).
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.
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.
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.
Hierarchical clustering (also called hierarchical cluster analysis or HCA) is a method of cluster analysis that seeks to build a hierarchy of clusters.
## References Wikipedia. (2021, August 10). Hierarchical clustering. [Link](https://en.wikipedia.org/wiki/Hierarchical_clustering) html)
Blocking the resolution of any subdomain of a specified domain name.
## 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.
Blocking DNS queries that are deceptively similar to legitimate domain names.
## 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.
A software firewall which controls network inbound and outbound network traffic to the host computer.
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.
## References Wikipedia. (n.d.). Statistical hypothesis testing. [Link](https://en.wikipedia.org/wiki/Statistical_hypothesis_testing)
Taking known malicious identifiers and determining if they are present in a system.
## 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
Image-to-image translation is the task of transferring styles and characteristics from one image domain to another.
## 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)
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.
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.
Image segments are distinct partitions of an object file. Both data and code segments are examples of image segments.
Analyzing vendor specific branch call recording in order to detect ROP style attacks.
## 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
Statistical inference is the process of using data analysis to infer properties of an underlying distribution of probability.
## References Wikipedia. (n.d.). Statistical inference. [Link](https://en.wikipedia.org/wiki/Statistical_inference)
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.
The practice of setting decoys in a production environment to entice interaction from attackers.
## 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
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 is multicast network traffic that does not cross a given network's boundaries.
Intranet web network traffic is network traffic that does not cross a given network's boundaries and uses a standard web protocol.
A JavaScript Blob is a Blob that was created by a JavaScript Blob() constructor call or equivalent function.
A ticket granting ticket issued by a Kerberos system; that is, a ticket that grants a user domain admin access.
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.
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.
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.
Ephemeral digital artifact comprising a request of a local resource and any response from that resource.
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.
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.
Analyzing a call stack for return addresses which point to unexpected memory locations.
## 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.
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).
Encrypting a message body using a cryptographic key.
## 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.
Multivariate statistics encompassed the simultaneous observation and analysis of more than one outcome variable, i.e., multivariate random variables.
A computer file resource made available from one host to other hosts on a computer network.
A summarization of network transactions between a client and server. It often summarizes bytes sent, bytes received, and protocol flags.
A computer file resource made available from one host to other hosts on a computer network that is also an initialization script.
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.
Establishing baseline communities of network hosts and identifying statistically divergent inter-community communication.
## 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 policy mapping identifies and models the allowed pathways of data at the network, tranport, and/or application levels.
Analyzing network traffic and compares it to known signatures
## 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 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.
Numeric pattern matching uses a pattern specification and sees if the numeric value matches that pattern--simple forms include exact matching and range matching.
An office application is one that is part of an application suite (e.g., Microsoft Office, Open Office).
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.
An operating system log file records events that occur in an operating system
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.
A d3f:Server which is involved with the orchestration of workloads or the execution of orchestrated workloads.
Outbound Internet Encrypted Remote Terminal Traffic
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.
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 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.
A page frame is the smallest fixed-length contiguous block of physical memory into which memory pages are mapped by the operating system.
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).
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.
Pattern matching is the act of checking a given sequence of tokens for the presence of the constituents of some pattern.
## References 1. Pattern matching. (2023, May 20). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Pattern_matching)
Detecting anomalies that indicate malicious activity by comparing the amount of data downloaded versus data uploaded by a host.
## 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.
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.
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.
A function which has an operation which dereferences a pointer.
Note, this is not the actual code which performs the dereferencing operation internal to an application runtime.
A PowerShell profile script is a script that runs when PowerShell starts and can be used as a logon script to customize user environments.
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.
## 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)
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.
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.
Detects processes that modify, change, or replace their own code at runtime.
## 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.
A function creates a new computer process, usually by invoking a create process system call.
Suspending a running process on a computer system.
## 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.
A process tree is a tree structure representation of parent-child relationships established via process spawn operations.
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.
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.
## References Wikipedia. (2021, September 7). Recurrent Neural Network. [Link](https://en.wikipedia.org/wiki/Recurrent_neural_network)
Reference - Active firewall system and methodology - McAfee LLC
System and methodology providing automated or "proactive" network security ("active" firewall) are described. The system implements methodology for verifying or authenticating communications, especially between network security components thereby allowing those components to share information. In one embodiment, a system implementing an active firewall is provided which includes methodology for verifying or authenticating communications between network components (e.g., sensor(s), arbiter, and actor(s)), using cryptographic keys or digital certificates. Certificates may be used to digitally sign a message or file and, in a complementary manner, to verify a digital signature. At the outset, particular software components that may participate in authenticated communication are specified, including creating a digital certificate for each such software component. Upon detection by a sensor that an event of interest that has occurred in the computer network system, the system may initiate authenticated communication between the sensor component and a central arbiter (e.g., "event orchestrator") component, so that the sensor may report the event to the arbiter or "brain." Thereafter, the arbiter (if it chooses to act on that information) initiates authenticated communication between itself and a third software component, an "actor" component (e.g., "firewall"). The arbiter may indicate to the actor how it should handle the event. The actor or firewall, upon receiving the information, may now undertake appropriate action, such as dynamically creating or modifying rules for appropriately handling the event, or it may choose to simply ignore the information.
Emilio Villa, Adrian Zidaritz, Michael David Varga, Gerhard Eschelbeck, Michael Kevin Jones, Mark James McArdle
Reference - Audit User Account Management
Audit User Account Management determines whether the operating system generates audit events when specific user account management tasks are performed.
Reference - CAR-2013-01-002: Autorun Differences - MITRE
The Sysinternals tool Autoruns checks the registry and file system for known identify persistence mechanisms. It will output any tools identified, including built-in or added-on Microsoft functionality and third party software. Many of these locations are known by adversaries and used to obtain Persistence. Running Autoruns periodically in an environment makes it possible to collect and monitor its output for differences, which may include the removal or addition of persistent tools. Depending on the persistence mechanism and location, legitimate software may be more likely to make changes than an adversary tool. Thus, this analytic may result in significant noise in a highly dynamic environment. While Autoruns is a convenient method to scan for programs using persistence mechanisms its scanning nature does not conform well to streaming based analytics. This analytic could be replaced with one that draws from sensors that collect registry and file information if streaming analytics are desired. Utilizes the Sysinternals autoruns tool (ignoring validated Microsoft entries). Primarily not a detection analytic by itself but through analysis of results by an analyst can be used for such. Building another analytic on top of this one identifying unusual entries would likely be a beneficial alternative.
Reference - CAR-2020-11-001: Boot or Logon Initialization Scripts - MITRE
Adversaries may schedule software to run whenever a user logs into the system; this is done to establish persistence and sometimes for lateral movement. This trigger is established through the registry key HKEY_CURRENT_USER\EnvironmentUserInitMprLogonScript. This signature looks edits to existing keys or creation of new keys in that path. Users purposefully adding benign scripts to this path will result in false positives; that case is rare, however. There are other ways of running a script at startup or login that are not covered in this signature. Note that this signature overlaps with the Windows Sysinternals Autoruns tool, which would also show changes to this registry path.
CAR-2020-11-001: Boot or Logon Initialization Scripts
Reference - CAR-2021-05-003: BCDEdit Failure Recovery Modification - MITRE
This search looks for flags passed to bcdedit.exe modifications to the built-in Windows error recovery boot configurations. This is typically used by ransomware to prevent recovery.
CAR-2021-05-003: BCDEdit Failure Recovery Modification
Reference - CAR-2016-03-002: Create Remote Process via WMIC - MITRE
Adversaries may use Windows Management Instrumentation (WMI) to move laterally, by launching executables remotely.The analytic CAR-2014-12-001 describes how to detect these processes with network traffic monitoring and process monitoring on the target host. However, if the command line utility wmic.exe is used on the source host, then it can additionally be detected on an analytic. The command line on the source host is constructed into something like wmic.exe /node:"\<hostname\>" process call create "\<command line\>". It is possible to also connect via IP address, in which case the string "\<hostname\>" would instead look like IP Address. Although this analytic was created after CAR-2014-12-001, it is a much simpler (although more limited) approach. Processes can be created remotely via WMI in a few other ways, such as more direct API access or the built-in utility PowerShell.
CAR-2016-03-002: Create Remote Process via WMIC
Reference - Database for receiving, storing and compiling information about email messages
Database for receiving, storing and compiling information about email messages
Reference - Decoy and deceptive data object technology - Cymmetria Inc
A computer implemented method of detecting unauthorized access to a protected network by monitoring a dynamically updated deception environment, comprising launching, on one or more decoy endpoints, one or more decoy operating system (OS) managing one or more of a plurality of deception applications mapping a plurality of applications executed in a protected network, updating dynamically a usage indication for a plurality of deception data objects deployed in the protected network to emulate usage of the plurality of deception data objects for accessing the deception application(s) wherein the plurality of deception data objects are configured to trigger an interaction with the deception application(s) when used, detecting usage of data contained in the deception data object(s) by monitoring the interaction and identifying one or more potential unauthorized operations based on analysis of the detection.
Dean Sysman; Gadi Evron; Imri Goldberg; Itamar Sher; Shmuel Ur
Reference - Detecting script-based malware - Crowdstrike Inc
Described herein are systems, techniques, and computer program products for preventing execution, by a scripting engine, of harmful commands that may be introduced by computer malware or other mechanisms. The system identifies certain host processes that may attempt to utilize a hosted scripting engine. An unmanaged interface module is injected into an identified host process. The unmanaged interface module is configured to detect certain conditions indicating the likelihood that a scripting engine will be instantiated, and in response to inject a managed interface module into the host process. The managed interface module hooks into certain methods of the scripting engine to intercept commands before they are executed by the scripting engine. The managed and unmanaged interface components then communicate with a kernel-mode threat detection component to determine whether any commands should be blocked.
The patent describes techniques that can be implemented to detect and block malicious commands and command scripts from being executed by scripting engines. ### Script Execution Monitoring explanation This patent describes software installed on the host system that hooks into methods of a scripting engine to intercept commands before they are executed and block commands if they are determined to be harmful. For example regular expression checking may be used to identify commands having malicious patterns. Expression checking may be used for script files as well as interactively - typed commands. ### File Content Signatures explanation This patent includes File Content Signatures because in the case of a script file, a hash of the file is compared against hashes of known malicious script files to determine whether the script file is malicious.
Reference - RFC 6376: DomainKeys Identified Mail (DKIM) Signatures - IETF
DomainKeys Identified Mail (DKIM) permits a person, role, or organization that owns the signing domain to claim some responsibility for a message by associating the domain with the message. This can be an author's organization, an operational relay, or one of their agents. DKIM separates the question of the identity of the Signer of the message from the purported author of the message. Assertion of responsibility is validated through a cryptographic signature and by querying the Signer's domain directly to retrieve the appropriate public key. Message transit from author to recipient is through relays that typically make no substantive change to the message content and thus preserve the DKIM signature.
RFC 6376: DomainKeys Identified Mail (DKIM) Signatures
Reference - Dynamic selection and generation of a virtual clone for detonation of suspicious content within a honey network - Palo Alto Networks Inc
Techniques for dynamic selection and generation of detonation location of suspicious content with a honey network are disclosed. In some embodiments, a system for dynamic selection and generation of detonation location of suspicious content with a honey network includes a virtual machine (VM) instance manager that manages a plurality of virtual clones executed in an instrumented VM environment, in which the plurality of virtual clones executed in the instrumented VM environment correspond to the honey network that emulates a plurality of devices in an enterprise network; and an intelligent malware detonator that detonates a malware sample in at least one of the plurality of virtual clones executed in the instrumented VM environment.
Dynamic selection and generation of a virtual clone for detonation of suspicious content within a honey network
Reference - Firewall for interent access - Secure Computing LLC
Regulating the flow of internetwork connections through a firewall (10) having a network protocol stack (14,16,18) which includes an Internet Protocol (IP) layer (16). A determination is made of the parameters characteristic of a connection request, including a netelement parameter characteristic of where the connection request came from. A query is generated and a determination is made whether there is a rule corresponding to that query. If there is a rule corresponding to the query, a determination is made whether authentication is required by the rule. If authentication is required by the rule, an authentication protocol is activated and the connection is activated if the authentication protocol is completed successfully.
Reference - Firewall for processing a connectionless network packet - National Security Agency
The present invention is a device for and method of accessing a network by initializing a database, an approved list, and a disapproved list; receiving an connectionless network packet; computing a flow tag based on the connectionless network packet; discarding the connectionless network packet and returning to the second step if the flow tag is on the disapproved list; allowing access to the network and returning to the second step if the flow tag is on the approved list; comparing the flow tag to the database if the flow tag is not on the approved list or the disapproved list; discarding the connectionless network packet, adding the flow tag to the disapproved list, and returning to the second step if the database rejects the flow tag; and allowing access to the network, adding the flow tag to the approved list, and returning to the second step if the database accepts the flow tag.
Firewall for processing a connectionless network packet
Reference - Firewall for processing connection-oriented and connectionless datagrams over a connection-oriented network - National Security Agency
The present invention is a device for and method of accessing an information network by initializing a database, an ATM approved list, an IP approved list, and an IP disapproved list; receiving a datagram; discarding the datagram if it is not on the ATM approved list; determining the datagram's type; allowing access to the network and comparing the connection request, if any, to the database if the datagram is ATM signaling; discarding the datagram if the datagram is ATM signaling and the database denies the request; adding the request to the ATM approved list if the datagram is ATM signaling and the database allows the request; allowing access to the network if the datagram is ATM data that excludes IP data and the request is on the ATM approved list; computing a flow tag if the datagram is ATM data that includes IP data; discarding the datagram if the flow tag is on the IP disapproved list; allowing access to the network if the flow tag is on the IP approved list; comparing the flow tag to the database if the flow tag is neither on the IP approved list nor on the IP disapproved list; discarding the datagram and adding the flow tag to the IP disapproved list if the database rejects the flow tag; and allowing access to the network and adding the flow tag to the corresponding approved list if the database accepts the flow tag; and performing these steps on the next datagram
Firewall for processing connection-oriented and connectionless datagrams over a connection-oriented network
Reference - Firewalls that filter based upon protocol commands - Intel Corp
Data transfer is controlled between a first network and a second network of computers by a firewall-proxy combination. Active interpretation of protocol commands exchanged between the first network and the second network is performed to determine specific actions concerning completion of the protocol request. This active firewall-proxy combination may exist on either the first or second network of computers. This method of control provides centralized control and administration for all potentially reachable resources within a network.
Firewalls that filter based upon protocol commands
Reference - Firmware Verification Trapezoid
A trust control management method for security, operable on a computer system generates a unique Trust ID value by combining user-defined values with hardware-specific values associated with the user's computer system and storing the Trust ID value in a memory register physically associated with the hardware of the computer system.
Michael J. Dyer, Jose E. Gonzalez, Albert Caballero
System and method for hardware-based trust control management
Reference - Identification of traceroute nodes and associated devices
Various embodiments pertain to communication network systems. In particular, various embodiments relate to multi-path probing in communication network systems that can be used to estimate the complete topology of the network. A method includes receiving data at a source node from a tracerouting probe in a network. The data includes information about at least one network node. The method also includes determining an identification for the at least one network node based on information. In addition, the method includes using the identification of the at least one network node to determine an identification of at least one device.
Tomas KUBIK, Lan Li, Tomas RYBKA, Karlo ZATYLNY, Chris O'Brien
Identification of traceroute nodes and associated devices
Reference - Libre NMS - Network Map Extension
LibreNMS has the ability to show you a network map based on: * xDP Discovery * MAC addresses
Reference - CAR-2019-07-002: Lsass Process Dump via Procdump - MITRE
ProcDump is a sysinternal command-line utility whose primary purpose is monitoring an application for CPU spikes and generating crash dumps during a spike that an administrator or developer can use to determine the cause of the spike. ProcDump may be used to dump the memory space of lsass.exe to disk for processing with a credential access tool such as Mimikatz. This is performed by launching procdump.exe as a privileged user with command line options indicating that lsass.exe should be dumped to a file with an arbitrary name.
CAR-2019-07-002: Lsass Process Dump via Procdump
Reference - Method for controlling computer network security - Checkpoint Software Technologies Ltd
A method of operating a security system for a computer network in which data is passed in said network as data packets, said system controlling the passage of said data packets in the network according to a security rule, where each aspect of said network controlled by said security rule has been defined, said security rule has been defined in terms of said aspects and converted into a set of filter language instructions.
Method for controlling computer network security
Reference - Near-Memory & In-Memory Detection of Fileless Malware
Fileless malware are recent threats to computer systems that load directly into memory, and whose aim is to prevent anti-viruses (AVs) from successfully matching byte patterns against suspicious files written on disk. Their detection requires that software-based AVs continuously scan memory, which is expensive due to repeated locks and polls. However, research advances introduced near-memory and in-memory processing, which allow memory controllers to trigger basic computations without moving data to the CPU. In this paper, we address AVs performance overhead by moving them to the hardware, i.e., we propose instrumenting processors’ memory controller or smart memories (near- and in-memory malware detection, respectively) to accelerate memory scanning procedures. To do so, we present MINI-ME, the Malware Identification based on Near- and In-Memory Evaluation mechanism, a hardware-based AV accelerator that interrupts the program’s execution if malicious patterns are discovered in their memory. We prototyped MINI-ME in a simulator and tested it with a set of 21 thousand in-the-wild malware samples, which resulted in multiple signatures matching with less than 1% of performance overhead and rates of 100% detection, and zero false-positives and false-negatives.
Marcus Botacin, André Grégio, Marco Antonio Zanata Alves
Near-Memory & In-Memory Detection of Fileless Malware
Reference - Network-level polymorphic shellcode detection using emulation
Network-level polymorphic shellcode detection using emulation
Reference - Network firewall with proxy - Secure Computing LLC
A proxy which is part of a firewall controls exchanges of information between two application entities. The proxy interrogates attempts to establish a communication session by requesting entities with a server entity in lower layers in accordance with defined authentication procedures. The Proxy interfaces with networking software to direct a communication stack to monitor connection requests to any address on specific ports. The requestor's address, and the server's address are checked against a access control list. If either address is invalid, the proxy closes the connection. If both are valid, a new connection is setup such that both the requestor and server are transparently connected to the proxy with variable higher levels being connected in a relay mode. Protocol data units are interrogated for conformance to a protocol session, and optionally further decoded to add additional application specific filtering. In one embodiment, an OSI architecture comprises the levels.
Reference - Overview of the seccomp sandbox
Reference - Platform Firmware Resiliency Guidelines - NIST
This document provides technical guidelines and recommendations supporting resiliency of platform firmware and data against potentially destructive attacks. The platform is a collection of fundamental hardware and firmware components needed to boot and operate a system. A successful attack on platform firmware could render a system inoperable, perhaps permanently, or requiring reprogramming by the original manufacturer, resulting in significant disruptions to users. The technical guidelines in this document promote resiliency in the platform by describing security mechanisms for protecting the platform against unauthorized changes, detecting unauthorized changes that occur, and recovering from attacks rapidly and securely. Implementers, including Original Equipment Manufacturers (OEMs) and component/device suppliers, can use these guidelines to build stronger security mechanisms into platforms. System administrators, security professionals, and users can use this document to guide procurement strategies and priorities for future systems.
Reference - CAR-2014-12-001: Remotely Launched Executables via WMI - MITRE
Adversaries can use Windows Management Instrumentation (WMI) to move laterally by launching executables remotely. For adversaries to achieve this, they must open a WMI connection to a remote host. This RPC activity is currently detected by CAR-2014-11-007. After the WMI connection has been initialized, a process can be remotely launched using the command: wmic /node:"<hostname>" process call create "<command line>", which is detected via CAR-2016-03-002. This leaves artifacts at both a network (RPC) and process (command line) level. When wmic.exe (or the schtasks API) is used to remotely create processes, Windows uses RPC (135/tcp) to communicate with the the remote machine. After RPC authenticates, the RPC endpoint mapper opens a high port connection, through which the schtasks Remote Procedure Call is actually implemented. With the right packet decoders, or by looking for certain byte streams in raw data, these functions can be identified. When the command line is executed, it has the parent process of C:\windows\system32\wbem\WmiPrvSE.exe. This analytic looks for these two events happening in sequence, so that the network connection and target process are output.
CAR-2014-12-001: Remotely Launched Executables via WMI
Reference - CAR-2013-09-003: SMB Session Setups - MITRE
Account usage within SMB can be used to identify compromised credentials, and the hosts accessed with them. This analytic monitors SMB activity that deals with user activity rather than file activity.
Reference - CAR-2014-03-001: SMB Write Request - NamedPipes - MITRE
An SMB write can be an indicator of lateral movement, especially when combined with other information such as execution of that written file. Named pipes are a subset of SMB write requests. Named pipes such as msftewds may not be alarming; however others, such as lsarpc, may. Monitoring SMB write requests still creates some noise, particularly with named pipes. As a result, SMB is now split between writing named pipes and writing other files.
CAR-2014-03-001: SMB Write Request - NamedPipes
Reference - Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 3.1
Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 3.1 Message Specification
Organizations risk losing revenue, customers, and reputation, and exposing internal or customer data to attackers if they do not properly manage Transport Layer Security (TLS) server certificates. TLS is the most widely used security protocol to secure web transactions and other communications on the internet and internal networks. TLS server certificates are central to the security and operation of internet-facing and internal web services. Improper TLS server certificate management results in significant outages to web applications and services-such as government services, online banking, flight operations, and mission-critical services within an organization-and increased risk of security breaches.
William Haag, Murugiah Souppaya, Paul Turner, William C. Barker, Brett Pleasant, Susan Symington
Reference - Software vulnerability graph database
To analyze open-source code at a large scale, a security domain graph language ("GL") has been created that functions as a vulnerability description language and facilitates program analysis queries. The SGL facilitates building and maintaining a graph database to catalogue vulnerabilities found in open-source components. This graphical database can be accessed via a database interface directly or accessed by an agent that interacts with the database interface. To build the graph database, a database interface processes an open-source component and creates graph structures which represent relationships present in the open-source component. The database interface transforms a vulnerability description into a canonical form based on a schema for the graph database and updates the database based on a determination of whether the vulnerability is a duplicate. This ensures quality and consistency of the vulnerability dataset maintained in the graph database.
Darius Tsien Wei FOO, Ming Yi ANG, Asankhaya Sharma, Jie Shun YEO
Reference - System and method for identifying the presence of malware using mini-traps set at network endpoints - Fidelis Cybersecurity Solutions Inc
A system for identifying the presence of advanced persistent threats on a network including a plurality of resources, interconnected to form a network, at least one decoy resource, at least one mini-trap installed on at least one of the plurality of resources and functionally associated with at one of the at least one decoy resource, the at least one mini-trap comprising deceptive information directing malware accessing the at least one mini-trap to the decoy resource associated therewith, and a manager node forming part of the network, locally or remotely, and configured to manage placement of the at least one mini-trap on the at least one of the plurality of resources and association between the at least one mini-trap and the decoy resource associated therewith.
Questionable or all files (as determined by the enterprise) are forwarded to the decoy network. Using a manager node user interface, you can setup fake information (ex. IP address of a decoy FTP server) and deploy decoy physical or virtual endpoints.
System and method for identifying the presence of malware using mini-traps set at network endpoints
Reference - System for implementing threat detection using daily network traffic community outliers - VECTRA NETWORKS Inc
A method and system for identifying insider threats within an organization is provided. The approach constructs an internal connectivity graph to identify communities of hosts/users, and checks for abnormal behavior relative to past behaviors.
David Lopes Pegna; Himanshu Mhatre; Oliver Brdiczka
This patent describes techniques for detecting insider attacks. Network packet capture data is collected and stored for processing. Metadata is extracted for each communication session on the organization's network and includes information on source and destination host destination port, number of connection attempts, size of data exchanged, duration and time of the communication. The metadata is used to build a connectivity graph of the network and identify groups of similar hosts that exhibit similar behavior. For each group of similar behavior identified, a baseline behavior pattern profile is developed. Network activity for a host within a group that deviates over a threshold from the baseline behavior patterns is identified as suspicious and an alert is generated.
System for implementing threat detection using daily network traffic community outliers
Reference - Systems and methods for detecting and/or handling targeted attacks in the email channel - Graphus Inc
Techniques for detecting and/or handling target attacks in an enterprise's email channel are provided. The techniques include receiving aspects of an incoming email message addressed to a first email account holder, selecting a recipient interaction profile and/or a sender profile from a plurality of predetermined profiles stored in a memory based upon the received properties, determining a message trust rating associated with the incoming email message based upon the incoming email message and the selected recipient interaction profile and/or the sender profile; and generating an alert identifying the incoming email message as including a security risk based upon the determined message trust rating. The recipient interaction profile includes information associating the first email account holder and a plurality of email senders from whom email messages have previously been received for the first email account holder, and the sender profile includes information associating a sender of the incoming email message with characteristics determined from a plurality of email messages previously received from the sender.
The patent describes using sender trust rating and sender MTA trust rating as an indicator of level of email security risk. ### Sender Reputation explanation This patent includes Sender Reputation because it describes sender trust rating being used as an indicator of the level of security risk and/or trust level associated with an email sender. The sender trust rating may be determined based on one or more of: * length of time sender has known the enterprise * number of recipients in the enterprise the sender interacts with * sender vs. enterprise originated message ratio * sender messages open vs. not-open ratio * number of emails received from this sender * number of emails replied for 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 Based on the trust rating an alert is generated identifying the incoming email message as a security risk. ### Sender MTA Reputation explanation This patent includes Sender MTA Reputation because it describes sender MTA trust rating as an indicator of the level of security risk and/or trust level associated with a sender MTA. The trust rating may be determined based on one or more of: * 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 Based on the trust rating an alert is generated identifying the incoming email message as a security risk.
Systems and methods for detecting and/or handling targeted attacks in the email channel
Reference - CAR-2016-04-002: User Activity from Clearing Event Logs - MITRE
It is unlikely that event log data would be cleared during normal operations, and it is likely that malicious attackers may try to cover their tracks by clearing an event log. When an event log gets cleared, it is suspicious. Alerting when a "Clear Event Log" is generated could point to this intruder technique. Centrally collecting events has the added benefit of making it much harder for attackers to cover their tracks. Event Forwarding permits sources to forward multiple copies of a collected event to multiple collectors, thus enabling redundant event collection. Using a redundant event collection model can minimize the single point of failure risk.
CAR-2016-04-002: User Activity from Clearing Event Logs
Reference - CAR-2013-02-012: User Logged in to Multiple Hosts - MITRE
Most users use only one or two machines during the normal course of business. User accounts that log in to multiple machines, especially over a short period of time, may be compromised. Remote logins among multiple machines may be an indicator of Lateral Movement. Certain users will likely appear as being logged into several machines and may need to be "whitelisted." Such users would include network admins or user names that are common to many hosts.
CAR-2013-02-012: User Logged in to Multiple Hosts
Reference - http://www.biometric-solutions.com/keystroke-dynamics.html - biometric-solutions.com
Keystroke dynamics or typing dynamics refers to the automated method of identifying or confirming the identity of an individual based on the manner and the rhythm of typing on a keyboard. Keystroke dynamics is a behavioral biometric, this means that the biometric factor is 'something you do'. Already during the second world war a technique known as The Fist of the Sender was used by military intelligence to distinguish based on the rhythm whether a morse code message was send by ally or enemy. These days each household has at least one computer keyboard, making keystroke dynamics the easiest biometric solution to implement in terms of hardware. With keystroke dynamics the biometric template used to identify an individual is based on the typing pattern, the rhythm and the speed of typing on a keyboard. The raw measurements used for keystroke dynamics are dwell time and flight time.
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
## References Reinforcement learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Reinforcement_learning).
The detection of an internal host relaying traffic between the internal network and the external network.
## 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.
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.
Restoring a file for an entity to access.
Restoring a user account's access to resources.
A script application process is an application process interpreting an executable script.
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.
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 processor.
A service dependency indicates a service has an activity, agent, or another service which relies on it in order to be functional.
A function which access a shared resource.
A application configuration database that contains or points to software shims (e.g., for backward compatibility, patches, etc.)
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.
Software that coordinates the deployment process of software to systems, typically remotely.
A tool that automates the process of packaging either or both binary code and source code for use on one or more target platforms.
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.
An environment created for the purpose of attracting attackers and eliciting their behaviors that is not connected to any production enterprise systems.
## 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.
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 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
## 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)
## References Supervised learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Supervised_learning).
Suspending a thread causes the thread to stop executing user-mode code.
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.
## 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)
A system dependency indicates a system has an activity, agent, or another system which relies on it in order to be functional.
A script used to initialize and configure elements of the system's environment, applications, services, or its operating system.
Computer software which enables operating system or platform functionality.
A system startup directory is a directory containing executable files or links to executable files which are run when the system starts.
A system time utility is utility software that can get the system time, such as the Unix date command or Windows' Net utility.
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.
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).
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)
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.
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.
used all over so its not just internet traffic
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)
File and Directory Permissions Modification
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.
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.
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.
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.
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.
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)
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)
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.
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.
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.
TFTP Network Traffic is network traffic typically used to automatically transfer configuration or boot files between machines.
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.
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.
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.
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.
## References Transfer learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Transfer_learning).
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).
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.
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.
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.
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.
Ephemeral digital artifact comprising a request of a network resource and any response from that network resource using a standard web protocol.
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.
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.
Creates a special File Object called Mailslot.
Typically used by Control Panel's "System" applet for creating new paged files.
Opens a handle to process obj and sets the access rights to this object.
Opens a handle to a thread object with the access specified.
Returns current time in Coordinated Universal Time (UTC) 8-bytes format.
Reads specified block from file into multiple buffers. Each buffer must have one page length.
Writes specified block of file with data from memory pages.
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.
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.
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.
x connects y: The subject x joins system y by means of communication equipment (to some other system, typically the adversary-targeted host).
date created
x d3fend-artifact-data-property y: The artifact x has the data property y.
x drives y: The device driver x causes a system component y to function by controlling it.
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.
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.
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.
x kb-is-example-of y: The reference x is an example of technique y.
x may-be-tactically-associated-with y: the defensive technique x may be a tactic that counters offensive technique y.
x may-interpret y: They entity x may interpret the thing y; that is, 'x interprets y' may be true.
x may-run y: They entity x may run the thing y; that is, 'x runs y' may be true.
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.
x originates-from y: The digital event or artifact x began its network transit from a physical location y.
x strengthens y: The technique x make digital artifact y resistant (to harm or misuse.)
x validates y: The technique x proves the digital artifact y is valid; that is, x shows or confirms the validity of y.
version
x version y: The product or service x has the version y.
x windows-registry-data-property y: The windows registry entry x has the property y.
Combines the principles of Artificial Neural Networks (ANN) and clustering methods.
## References Wikipedia. (n.d.). Artificial neural network. [Link](https://en.wikipedia.org/wiki/Artificial_neural_network)
A process in which a computer examines information using mathematical methods in order to find useful patterns.
An application process is an instance of an application computer program that is being executed.
The classification of someone or something with respect to its worth.
Analyzing sequences of bytes and determining if they likely represent malicious shellcode.
## 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 this. Process Segment Execution Prevention combined with Segment Address Offset Randomization frequently makes introduction of shellcode through overwriting a saved return pointer more difficult. Call stack depth analysis might detect excessive reuse of instructions in the target binary. Shadow Stack Frames might detect that a stack frame's return address has changed and Stack Frame Canary Verification might detect that the stack frame's return address was overwritten. Other heuristic methods might detect jump-oriented programming shellcode. With inserting code directly, that it is not a buffer overflow, and just some place where code is executed either to a file or a write-what-where, the buffer overflow mitigations do not help. Behavioral analysis could detect this, or proper access control could mitigate this. ### False Positives Byte sequences containing code that is never used as machine code are still analyzed and flagged for anomalies, and [eventually](http://mathforum.org/library/drmath/view/55871.html), it is likely that an attack sequence will arise from the sheer volume of bytes transmitted.
Improper Handling of Invalid Use of Special Elements
Generation of Error Message Containing Sensitive Information
Externally-Generated Error Message Containing Sensitive Information
Improper Handling of Structural Elements
Incorrect Usage of Seeds in Pseudo-Random Number Generator (PRNG)
Generation of Predictable Numbers or Identifiers
Use of Invariant Value in Dynamically Changing Context
Insertion of Sensitive Information into Externally-Accessible File or Directory
Inclusion of Sensitive Information in Source Code
Improper Handling of File Names that Identify Virtual Resources
Allocation of Resources Without Limits or Throttling
Missing Release of Resource after Effective Lifetime
Access of Memory Location After End of Buffer
Reliance on Untrusted Inputs in a Security Decision
Inclusion of Functionality from Untrusted Control Sphere
Improper Control of Generation of Code ('Code Injection')
Improper Control of Resource Identifiers ('Resource Injection')
Analyzing Public Key Infrastructure certificates to detect if they have been misconfigured or spoofed using both network traffic, certificate fields and third-party logs.
## 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.
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.
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."
Determining which credentials may have been compromised by analyzing the user logon history of a particular system.
## 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/shadow file. Reading from /proc directory: mimipenguin, many others. ## Considerations Effective implementation requires identifying any location that could end up containing credentials, and detecting an method of potential access to a source of credential data. 1. https://medium.com/blue-team/preventing-mimikatz-attacks-ed283e7ebdd5
Expiring an existing set of credentials and reissuing a new valid set
## How it works 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. ## Considerations - 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.
Permitting only approved domains and their subdomains to be resolved.
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.
Removing unreachable or "dead code" from compiled source code.
## 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.
Establishing a fake online identity to misdirect, deceive, and or interact with adversaries.
## 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.
Assessing how well a capability implementation's capability feature functions as a countermeasure.
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.
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.
## 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)
The properties derived from a probability distribution.
Analyzing the reputation of a domain name.
Validates that a referenced exception handler pointer is a valid exception handler.
## 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 handlers being compromised. ### Compile-time The source of valid exception handlers could also be generated at compile time or as a binary patch. Given the source code, it would be rather straightforward to find the exceptions, as they are pointed in the catch statement of a try-catch clause and the compiler must already generate the code to call exceptions from this. ## Considerations If the program file can be altered by the attacker, then the security could be bypassed by replacing it with any desired program, without even bypassing SEH. If the attacker was already able to overwrite the code for a valid exception handler via other functionality in the program, this defense would not prevent arbitrary code execution. If an exception handler recognized as valid is vulnerable, it would be executed anyway. SafeSEH might be applied only to some executable files or modules, allowing an attacker to call any piece of code as an exception handler in the unprotected modules.
Analyzing the files accessed by a process to identify unauthorized activity.
## 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.
Employing a pattern matching algorithm to statically analyze the content of files.
## 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.
Detecting any suspicious changes to files in a computer system.
## 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.
The file removal technique deletes malicious artifacts or programs from a computer system.
## 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.
Analyzing the behavior of embedded code in firmware and looking for anomalous behavior and suspicious activity.
## 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.
Monitoring code is injected into firmware for integrity monitoring of firmware and firmware data.
## 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.
Blocking a lookup based on the query's domain name value.
## 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.
Generative Adversarial Networks (GAN) are an approach to generative modeling using deep learning methods, such as convolutional neural networks.
## References Brownlee, J. (2019). What Are Generative Adversarial Networks (GANs)? Machine Learning Mastery. [Link](https://machinelearningmastery.com/what-are-generative-adversarial-networks-gans/)
Initiating a host's shutdown sequence to terminate all running processes.
## 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.
Analyzing the reputation of an IP address.
Image synthesis thorugh the application of Generative Adversarial Networks.
## 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)
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.
Logical link mapping creates a model of existing or previous node-to-node connections using network-layer data or metadata.
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.
## 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).
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.
## 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).
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.
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
Information used to configure the services, parameters, and initial settings for an operating system.
Passive physical link mapping only listens to network traffic as a means to map the physical layer.
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.
Cryptographically verifying peripheral firmware integrity.
# 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
Physical link mapping identifies and models the link connectivity of the network devices within a physical network.
Adding physical barriers to a platform to prevent undesired radio interference.
Reference - Automatically generating rules for connection security - Microsoft
A method and system for creating security policies for firewall and connection policies in an integrated manner is provided. The security system provides a user interface through which a user can define a security rule that specifies both a firewall policy and a connection policy. After the security rule is specified, the security system automatically generates a firewall rule and a connection rule to implement the security rule. The security system provides the firewall rule to a firewall engine that is responsible for enforcing the firewall rules and provides the connection rule to an IPsec engine that is responsible for enforcing the connection rules
Charles D. Bassett; Eran Yariv; Ian M. Carbaugh; Lokesh Srinivas Koppolu; Maksim Noy; Sarah A. Wahlert; Pradeep Bahl
Automatically generating rules for connection security
Reference - Firmware Verification Eclypsium
Systems and methods are provided herein for monitoring and identifying potential security vulnerabilities in hardware and / or firmware of host devices .
Methods and systems for hardware and firmware security monitoring
Reference - System and method thereof for identifying and responding to security incidents based on preemptive forensics - Palo Alto Networks Inc
A system is connected to a plurality of user devices coupled to an enterprise's network. The system continuously collects, stores, and analyzes forensic data related to the enterprise's network. Based on the analysis, the system is able to determine normal behavior of the network and portions thereof and thereby identify abnormal behaviors within the network. Upon identification of an abnormal behavior, the system determines whether the abnormal behavior relates to a security incident. Upon determining a security incident in any portion of the enterprise's network, the system extracts forensic data respective of the security incident and enables further assessment of the security incident as well as identification of the source of the security incident. The system provides real-time damage assessment respective of the security incident as well as the security incident's attributions.
This patent describes detecting abnormal behavior related to a security incident by collecting and analyzing forensic data in real time. Forensic data may include: * URLs visited * data downloaded or streamed * messages received and sent * amount of memory used for processing The data is then analyzed according to a set of dynamically created rules to determine normal behavior patterns associated with the network or user devices. Anomalies between current behavior and normal behavior patterns trigger an alert.
System and method thereof for identifying and responding to security incidents based on preemptive forensics
Reference - Tivoli Application Dependency Discovery Manager 7.3.0 - Dependencies between resources
Tivoli Application Dependency Discovery Manager 7.3.0 - Dependencies between resources
Reference - Web-Based Enterprise Management
Distributed Management Task Force (DMTF)
Reference - Windows Management Infrastructure (MI)
Reference - Windows Management Instrumentation (WMI)
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
## 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).
Restoring an entity's access to resources.
Blocking a reverse DNS lookup's answer's domain name value.
## How it works In reverse resolution requests, the client sends to a nameserver (such as a DNS server) a query of an IP address, to get a response of the associated domain name(s). This technique drops reverse lookup responses where a domain name matches an entry in the blacklist, either verbatim or as a wildcard subdomain of a higher-level domain on the list. Such domain names might be unwanted because Forward Domain Name Resolution requests to such a blacklisted domain might return an unwanted IP address. This technique is useful because relying solely on Forward Resolution Domain Blacklisting will miss instances where the domain in question is forward-resolved in a manner that is not inspected via a subsequent technique (as is likely the case if that resolution is performed with DoH (DNS over HTTPS) or DoT (DNS over TLS)). Additionally, note that responses to forward lookups of that domain are *not* necessarily equal to the original IP in the reverse lookup request, and that future lookups of a string based on this domain may even employ a less-common name resolution protocol, such as NBNS. The DNS response can either be blocked by dropping the network traffic with an inline device, or by modifying the value of the response sent by the DNS server. To prevent client applications from hanging on a request, it is common practice to replace malicious values, either with names like "localhost." or the address of a honeypot maintained by the network administrators. ## Considerations * This technique does not prevent the client from contacting the blacklisted domain or any IP addresses that it might resolve to, only from learning about this domain name via a nameserver lookup. * DNS response traffic can be transmitted over many different protocols, which presents a challenge to implementing methods to extract all DNS answer domain name 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 deployed between the application that receives the response and the server which sent the response. * DNS responses sent in an encrypted manner, such as using DoH or DoT, will require interception of the TLS connections in order to determine the domain name(s) in the response. * Replacing the response is not effective in the case that the nameserver uses a technique to provide integrity of its responses, such as DNSSEC for DNS responses.
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.
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.
## 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/).
Analyzing changes in service binary files by comparing to a source of truth.
## 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.
Comparing a call stack in system memory with a shadow call stack maintained by the processor to determine unauthorized shellcode activity.
## 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.
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.
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.
A system configuration initialization resource has information for initializing (booting) a system.
Cryptographically verifying installed system firmware integrity.
## 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
Analysis of any system process startup configuration.
System Initialization Configuration Analysis
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.
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.
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.
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.
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.
Adversaries may manipulate products or product delivery mechanisms prior to receipt by a final consumer for the purpose of data or system compromise.
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).
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.
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)
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)
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)
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)
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.
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.
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.
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.
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)
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.
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.
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)
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.
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.
## References "Transformer (machine learning model)." Wikipedia. [Link](https://en.wikipedia.org/wiki/Transformer_(machine_learning_model)).
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.
## 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).
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.
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.
x d3fend-kb-annotation-property y: The entity x had the d3fend kb annotation y.
x d3fend-kb-data-property y: The reference x has the data property y.
x encrypts y: The entity x converts the ordinary representation of a digital artifact y into a secret code.
x forges y: An technique or agent x counterfeits a digital artifact y, such as a fake credential, with the intent to deceive.
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.'
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.
x process-property y: Process x has the a process-property y. This is generalization for specific process object properties.
x records y: The digital artifact x makes a record of events y; set down in permanent form.
x suspends y: The agent or technique x pauses entity y.
A list of permissions attached to an object.
Administrative Network Activity Analysis
Detection of unauthorized use of administrative network protocols by analyzing network activity against a baseline.
## 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
Authenticates a user account by verifying a presented credential.
Cryptographically authenticating the bootloader software before system boot.
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."
Incomplete Comparison with Missing Factors
Improper Handling of Physical or Environmental Conditions
Improper Handling of Syntactically Invalid Structure
Use of a Broken or Risky Cryptographic Algorithm
Improper Interaction Between Multiple Correctly-Behaving Entities
Modification of Assumed-Immutable Data (MAID)
Improper Neutralization of Special Elements used in a Command ('Command Injection')
Broad and could apply to all resource accesses.
Improper Neutralization of Special Elements in Data Query Logic
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).
A distinguishing characteristic of a capability (e.g., performance, portability, or functionality).
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
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.
A user account on a given host is a local user account for a given cloud and specified resources within that cloud.
A log of commands run in an operating system shell.
A file containing Information used to configure the parameters and initial settings for a compiler.
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.
Configuration inventory identifies and records the configuration of software and hardware and their components throughout the organization.
## 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)."
A control catalog is a complete list of protective measures for systems, organizations, or individuals for subject domains (e.g., security and privacy.)
A create socket system call creates an endpoint for communication and returns a file descriptor that refers to that endpoint.
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.
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.
The deceive tactic is used to advertise, entice, and allow potential attackers access to an observed or controlled environment.
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.
## 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**: Not all of the following may be necessary, but should be considered for both verification (developmental test) and operational test stages use: - **Accuracy**: The fraction of predictions that were corret. - **Precision**: The proportion of positive identifications that were correct. - **Recall**: The proportion of actual positive cases identified correctly. - **F-Measure**: Combines the preicion and recall into a single score. It is the harmonic mean of the precision and recall. - **Receiver Operating Characteristic (ROC) Curve**: A ROC curve shows the performance of a classification model at all classification thresholds. It graphs the True Positive Rate over the False Positive Rate. - **Area Under the ROC Curve (AUC)**: This measures the two-dimensional area under the ROC Curve. AUC is scale-invariant and classification-threshold invariant. - **ROC TP vs FP points**: In addition to a specific AUC score, the performance at points - **Confusion Matrix**: A confusion matrix is a table layout that allows the visualization of the performance of an algorithm. Each row of the matrix represents the instances in an actual class while each column represents the instances in a predicted class, or vice versa. It is a special kind of contingency table, with two dimensions ("actual" and "predicted"), and identical sets of "classes" in both dimensions (each combination of dimension and class is a variable in the contingency table.) - **Prediction Bias**: The difference between the average of the predicted labels and the average of the labels in the data set. One should check for prediction bias when evaluating the classifier's results. Causes of bias can include: - **Noisy data set**: Errors in original data can as the collection method may have an underlying bias. - **Processing bug**: Errors in the data pipeline can introduce bias. - **Biased training sample (unbalanced samples)**: Model parameters may be skewed towards majority classes. - **Overly strong regularization**: Model may be underfitting model and too simple. - **Proxy variables**: Model features may be highly correlated. - **Supervised Learning**: - **Overfitting and Underfitting**: Overfitting occurs when the the model built corresponds too closely or exactly to a particular set of data, and thus may fail to fit to predict additional data reliably. An overfitted model is a mathematical model that contains more parameters than can be justified by the data. Underfitting occurs when the model built does adequately capture the patterns in the data. As an example, a linear model will underfit a non-linear dataset. - **Sensitivity**: Perform N-fold Cross validation to indicate how much sensitivity the algorithm has to data variation and to avoid overfitting operational models. - **Decision Tree Learning**: - **Sensitive to unbalanced classes**: Examine and determine target class balance; decision tree learning algorithms are especially sensitive to unbalanced target classes. - **Consider decision boundaries**: Perform exploratory data analysis to determine if decision boundaries lie alongaxes of features. _Decision trees are ideal when decision boundaries can be found that lie along axes of features._ - **Decision tree overfitting** may require tuning algorithm hyperparameters such as tree depth, max features used, max leaf nodes, etc. - **Pruning** may result in a more robust model in real-word applications. - **Missing values**: Inspect the data set to determine if there are missing values and select a means to address them, either by choosing an algorithm that works well or a way to impute the value or eliminate the missing values in the data sensors or pipeline. ## Platforms, Tools, or Libraries - **scikit-learn**: includes tree algorithms for ID3, C4.5, C5.0, and CART. - **Weka**: includes J48 (C4.5), SimpleCart (CART), Logistic Model Trees, Naive Bayes Trees, and more. ### Validation Approach - Use operationally relevant data across the range of application's operating environment. - Incorporate some kind of continuous validation to address concept drift and the need to retrain the model and/or check data quality. ## References 1. Decision tree learning. (2023, May 30). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Decision_tree_learning). 2. Decision Trees. (n.d.). In _scikit-learn User Guide 1.2.2_. [Link](https://scikit-learn.org/stable/modules/tree.html). 3. Concept drift. (2023, April 17). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Concept_drift). 4. 8 Concept Drift Detection Methods. (n.d.). In _Aporia Learning Center_. [Link](https://www.aporia.com/learn/data-drift/concept-drift-detection-methods/).
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).
A Credential created for the purpose of deceiving an adversary.
## 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.
Descriptive statistics provide simple summaries about the sample and about the observations that have been made.
## References Wikipedia. (n.d.). Descriptive statistics. [Link](https://en.wikipedia.org/wiki/Descriptive_statistics)
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.
A configuration of an email application which is used to apply logical or data processing functions to data processed by the email application.
Emulating instructions in a file looking for specific patterns.
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.
## 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.
Takes inputs of strings and evaluations them as expressions.
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.
The cluster analysis of data with anywhere from a few dozen to many thousands of dimensions.
## References Wikipedia. (n.d.). Clustering high-dimensional data. [Link](https://en.wikipedia.org/wiki/Clustering_high-dimensional_data)
Comparing strings using a variety of techniques to determine if a deceptive or malicious string is being presented to a user.
## 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
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.
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 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 traffic is network traffic originating from another host (client), to the host of interest (server).
Operating system level mechanisms to prevent abusive input device exploitation.
## 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. ## Considerations Given some example of legitimate behavioral input patterns, attackers could mimic those input patterns, a technique which has been used in popular culture in the creation of Deepfake videos and [This Person Does Not Exist](https://thispersondoesnotexist.com).
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.
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.
## References Beginner's Guide to Semi-Supervised Learning. Jashish Blog. [Link](http://jashish.com.np/blog/posts/beginners-guide-to-semi-supervised-learning/).
The isolate tactic creates logical or physical barriers in a system which reduces opportunities for adversaries to create further accesses.
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.
## 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.
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.
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.
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.
Logic programming is a programming paradigm which is largely based on formal logic.
## 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)
In computing, a memory address is a reference to a specific memory location used at various levels by software and hardware.
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.
Authenticating the sender of a message and ensuring message integrity.
## 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.
Email or Messaging Hardening includes measures taken to ensure the confidentiality and integrity of user to user computer messages.
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.
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.
## References 1. Modal logic. (2023, June 4). In _Wikipedia_. [Link](https://en.wikipedia.org/wiki/Modal_logic)
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.
## References Model-free (reinforcement learning). Wikipedia. [Link](https://en.wikipedia.org/wiki/Model-free_(reinforcement_learning)).)
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.
A NIST SP 800-53 control catalog provides the entire set of security and privacy controls for a version of NIST SP 800-53.
An object file is a file that contains relocatable machine code.
A document file in a format associated with an d3f:OfficeApplication.
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.
Organization mapping identifies and models the people, roles, and groups with an organization and the relations between them.
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.
Numeric pattern matching is a method of matching some defined pattern specification against a numeric value.
Collecting host certificates from network traffic or other passive sources like a certificate transparency log and analyzing them for unauthorized activity.
## 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 final label score. Supervised learning is also employed using the curated domains of benign and phishing domains. * Subdomain phishing analysis, prepending a trusted domain to a phishing domain, and regular expression comparisons are also used in the label scoring model. A tunable measure is used to determine the threshold for alerting. This measure helps to balance between precision and recall measures. ## Considerations * Some entity will need to run the logging service and a trusted entity is preferred. * Certificate Authorities will likely need to monitor the logging service for consistency. * Certificate revocation is unchanged and remains outside of Certificate Transparency, but certificates needing to be revoked are visible. * Technique dependent of reliable feed of new and updated certificates * Some certificate authorities allow for certificates to be registered with wildcards in the FQDN and thus will fail some of the subdomain scoring * Phishing HTTP domains will not be discovered
A user repository of account passwords, often accessed via a password manager.
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.
Collecting network communication protocol metadata and identifying statistical outliers.
## 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.
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.
A Remote Desktop Protocol (RDP) session is a session established using the RDP protocol to access Remove Desktop Services (RDS).
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.
Wikipedia. (n.d.). Rank correlation. [Link](https://en.wikipedia.org/wiki/Rank_correlation)
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.
Geoffrey John Hulten, Paul Stephen Rehfuss, Robert Rounthwaite, Joshua Theodore Goodman, Gopalakrishnan Seshadrinathan, Anthony P. Penta, Manav Mishra, Roderic C. Deyo, Elliott Jeb Haber, David Aaron Ward Snelling
Reference - Host intrusion prevention system using software and user behavior analysis - Sophos Ltd
In embodiments of the present invention improved capabilities are described for threat detection using a behavioral-based host-intrusion prevention method and system for monitoring a user interaction with a computer, software application, operating system, graphic user interface, or some other component or client of a computer network, and performing an action to protect the computer network based at least in part on the user interaction and a computer code process executing during or in association with a computer usage session.
The patent describes a technique for performing behavior based threat detection. User and code behavior data is collected and stored to create baseline user and code behavior profiles. User behavior data collected over a user session or over multiple sessions can include a user: * clicking on a link * scrolling down a page * opening or closing a window * downloading a file * saving a file * running a file * typing a keyword Code behavior monitored includes code: * copying itself to a system folder * setting a run key to itself in the registry * setting a second runkey to itself in the registry in a different location * disabling OS tools in the registry * opening a hidden file The user interaction and the code process executed during the user session are monitored and compared with predetermined malicious behavior profiles that are typically present in a malicious user session. The predetermined collection of malicious behaviors are created based on analysis of families of malware in run time in a threat research facility. If a match is made an action is taken that can include isolating the computer on which the user interaction occurs and limiting network access to or from the computer.
Host intrusion prevention system using software and user behavior analysis
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.
Ephemeral digital artifact comprising a request of a resource and any response from that resource.
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.
The restore tactic is used to return the system to a better state.
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.
Analysis of source files, processes, destination files, or destination servers associated with a scheduled job to detect unauthorized use of job scheduling.
## 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.
Analyzing the execution of a script to detect unauthorized user activity.
## 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.
Randomizing the base (start) address of one or more segments of memory during the initialization of a process.
## 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 back into memory, or execute a function, that changes the address of a stack pointer. If an attacker wants to inject some data into the program, for example as a parameter to a known function that is not under ASLR or a pointer to a trampoline function in the PLT, then they can repeat the data until they exceed the range of ASLR coverage, which on 32-bit systems is accomplishable in a few seconds with a heap spray. Microsoft's EMET and Windows 10 Exploit Guard can pre-allocate particular addresses that are commonly used in heap sprays. However, in many products, there does not seem to be nearly a complete coverage of such addresses, which only need to be executable and in the range of the heap; 0x0c0c0c0c is such an address that is commonly used for the x86 processor architecture, as when executed it only performs a numeric operation to a register four times.
Service dependency mapping determines the services on which each given service relies.
## 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
A computer whose resources are intended to be shared widely.
Software inventorying identifies and records the software items in the organization's architecture.
## 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)
Comparing a value stored in a stack frame with a known good value in order to prevent or detect a memory segment overwrite.
## 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 B5000, the stack grows towards increasing memory addresses, and some architectures, such as System Z and RCA1802A, stack direction can be chosen. If the stack grows towards increasing memory addresses, while this architecture inherently provides more protection against a saved register being overwritten, other data including local function variables might be overwritten. ## Considerations There are several ways that the protection provided by a canary could be rendered ineffective. ### Performing a malicious action before the canary is checked If the attacker alters the memory in such a way that it performs a malicious action before the epilogue is called, then this protection will not be effective. This includes altering the logic of the program by altering the values of local variables stored on the function stack, or by causing an exception and exploiting the exception mechanism such as the SEH (Structured Exception Handling) mechanism on Windows. ### Determining the canary value Determining the canary value is possible through reading memory either for the code used to check the canary, or from the stored canary value itself in a stack frame. ### Changing the canary value A vulnerability such as a write-what-where condition that allows one to write data after the canary in the stack, would allow control of the value of the saved instruction pointer without needing to know the canary value.
The configuration for a individual host operating system's firewall.
A password database used by a system service or process to authenticate users (e.g., Security Account Manager)
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)).
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.
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.
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.
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.
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.
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.
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.
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.
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)
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.
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.).
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.
Determining if a URL is benign or malicious by analyzing the URL or its components.
## 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
A Unix link is a file link in a Unix file system.
Unsupervised learning creates relationships with unlabeled data without the input of a human or other outside actor. Uses only input data.
## References Unsupervised learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Unsupervised_learning).
Monitoring geolocation data of user logon attempts and comparing it to a baseline user behavior profile to identify anomalies in logon location.
## 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.
Analyzing modifications to user session config files such as .bashrc or .bash_profile.
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.
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.
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).
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.
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.
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.
x disables y: The technique or agent x makes an entity y unable to perform its actions or capabilities.
x isolates y: The technique or agent x sets digital artifact y apart from other digital artifacts, sequestering y.
x process-data-property y: The process x has the data property y.
x terminates y: The technique x brings to an end or halt to some activity y.
A database used to hold application configuration data.
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.
Broadcast isolation restricts the number of computers a host can contact on their LAN.
## 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.
Improper Neutralization of Trailing Special Elements
Sensitive Information in Resource Not Removed Before Reuse
Improper Link Resolution Before File Access ('Link Following')
Function Call with Incorrectly Specified Arguments
Operation on Resource in Wrong Phase of Lifetime
Incorrect Resource Transfer Between Spheres
Operation on a Resource after Expiration or Release
Multiple Operations on Resource in Single-Operation Context
Incorrect Conversion between Numeric Types
Improper Control of Dynamically-Managed Code Resources
Information used to configure the services, parameters, and initial settings for a virtual server instance running in a cloud service..
Correlation is the degree to which two or more quantities are linearly associated.
Wolfram MathWorld. (n.d.). Correlation. [Link](https://mathworld.wolfram.com/Correlation.html)
Credential Eviction techniques disable or remove compromised credentials from a computer network.
A specific query expressed in SQL, SPARQL, or similar language against a database.
A file created for the purposes of deceiving an adversary.
## 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.
An application used to develop computer software including applications used for software construction, analysis, testing, packaging, or management.
A document is a written, drawn, presented or recorded representation of thoughts.
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.
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.
Analyzing the reputation of an identifier.
In computing, a login session is the period of activity between a user logging in and logging out of a (multi-user) system. On Unix and Unix-like operating systems, a login session takes one of two main forms: (a) When a textual user interface is used, a login session is represented as a kernel session -- a collection of process groups with the logout action managed by a session leader, and (b) Where an X display manager is employed, a login session is considered to be the lifetime of a designated user process that the display manager invokes.
Analyzing email or instant message content to detect unauthorized activity.
## 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.
Network node inventorying identifies and records all the network nodes (hosts, routers, switches, firewalls, etc.) in the organization's architecture.
## 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)
Ephemeral digital artifact comprising a request of a network resource and any response from that network resource.
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.
Restricting network traffic originating from any location.
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.
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.
Process eviction techniques terminate or remove running process.
Reference - Method and Apparatus for Network Fraud Detection and Remediation Through Analytics - Idaptive LLC
A system and method for assessing the identity fraud risk of an entity's (a user's, computer process's, or device's) behavior within a computer network and then to take appropriate action. The system uses real-time machine learning for its assessment. It records the entity's log-in behavior (conditions at log-in) and behavior once logged in to create an entity profile that helps identify behavior patterns. The system compares new entity behavior with the entity profile to determine a risk score and a confidence level for the behavior. If the risk score and confidence level indicate a credible identity fraud risk at log-in, the system can require more factors of authentication before log-in succeeds. If the system detects risky behavior after log-in, it can take remedial action such as ending the entity's session, curtailing the entity's privileges, or notifying a human administrator.
This patent describes determining a confidence score to detect anomalies in user activity based on comparing a user's behavior profile with current user activity events. The following types of events are used to develop a user entity profile: * logon and logoff times and locations * starting or ending applications * reading or writing files * changing an entity 's authorization * monitoring network traffic User events that deviate from the entity profile over a certain threshold trigger a remedial action.
Method and Apparatus for Network Fraud Detection and Remediation Through Analytics
Reference - System, method, and computer program product for detecting and assessing security risks in a network - Exabeam Inc
The present disclosure is directed to a system, method, and computer program for detecting and assessing security risks in an enterprise's computer network. A behavior model is built for a user in the network based on the user's interactions with the network, wherein a behavior model for a user indicates client device(s), server(s), and resources used by the user. The user's behavior during a period of time is compared to the user's behavior model. A risk assessment is calculated for the period of time based at least in part on the comparison between the user's behavior and the user's behavior model, wherein any one of certain anomalies between the user's behavior and the user's behavior model increase the risk assessment.
Sylvain Gil; Domingo Mihovilovic; Nir Polak; Magnus Stensmo; Sing Yip
This patent describes calculating a risk score to detect anomalies in user activity based on comparing a user's current session with a user behavior model. The user behavior model is comprised of a number of histograms including: * client devices from which the user logs in * servers accessed * data accessed * applications accessed * session duration * logon time of day * logon day of week * geo - location of logon origination The system has an initial training period with x number of days (e. g., 90 days) in which session data is recorded in behavior models before behavior analysis begins.The histograms are then used to determine anomalies between current session activity and a user's behavior model. Values for a histogram category are along one axis and the number of times the value is received for the category is along another axis. If a data point value associated with the current user session is over an anomaly threshold, an alert is generated.
System, method, and computer program product for detecting and assessing security risks in a network
Reference - Unified Architecture Framework (UAF)
UAF is an OMG standard that assists in development of architectural descriptions in commercial industry firms, federal government agencies and defense organizations. UAF has a variety of use cases from Enterprise and Mission architecting, to System of Systems (SoS) and Cyber-physical Systems engineering, as well as being an enabler for Digital Transformation efforts and for Department of Defense Architecture Framework (DoDAF) and NATO Architecture Framework (NAF) modeling. Architectural Descriptions in UAF are aligned with ISO/IEC/IEEE 42010:2011, Systems and software engineering -- Architecture description.
Reference - Use DNS Policy for Applying Filters on DNS Queries
Use DNS Policy for Applying Filters on DNS Queries
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').
## References Wikipedia. (n.d.). Regression analysis. [Link](https://en.wikipedia.org/wiki/Regression_analysis)
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.
## References Semi-Supervised Learning. Wikipedia. [Link](https://en.wikipedia.org/wiki/Semi-Supervised_Learning).
Characterizing the reputation of mail transfer agents (MTA) to determine the security risk in emails.
## 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.
Ascertaining sender reputation based on information associated with a message (e.g. email/instant messaging).
## 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.
Analyzing the duration of user sessions in order to detect unauthorized activity.
## 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.
System dependency mapping identifies and models the dependencies of system components on each other to carry out their function.
## 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 initialization configuration information is configuration information used to configure the services, parameters, and initial settings for an operating system at startup.
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.
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.
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.
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)
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)
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)
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.
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)
Time series analysis comprises methods for analyzing time series data in order to extract meaningful statistics and other characteristics of the data.
## References Wikipedia. (n.d.). Time series. [Link](https://en.wikipedia.org/wiki/Time_series)
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.
x may-transfer y: They entity x might send the thing y; that is, 'x transfers y' may be true.
x verifies y: A technique x confirms the truth of a digital artifact y.
Active learning aims to improve learning efficiency by allowing the learning algorithm to select which data to learn from.
## 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)
Asset vulnerability enumeration enriches inventory items with knowledge identifying their vulnerabilities.
Removing tokens or credentials from an authentication cache to prevent further user associated account accesses.
## 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
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.
Always-Incorrect Control Flow Implementation
Incorrect Permission Assignment for Critical Resource
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.
## 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.
Classification uses an algorithm to accurately assign test data into specific categories.
## 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 fraction of predictions that were corret. - **Precision**: The proportion of positive identifications that were correct. - **Recall**: The proportion of actual positive cases identified correctly. - **F-Measure**: Combines the preicion and recall into a single score. It is the harmonic mean of the precision and recall. - **Receiver Operating Characteristic (ROC) Curve**: A ROC curve shows the performance of a classification model at all classification thresholds. It graphs the True Positive Rate over the False Positive Rate. - **Area Under the ROC Curve (AUC)**: This measures the two-dimensional area under the ROC Curve. AUC is scale-invariant and classification-threshold invariant. - **ROC TP vs FP points**: In addition to a specific AUC score, the performance at points - **Confusion Matrix**: A confusion matrix is a table layout that allows the visualization of the performance of an algorithm. Each row of the matrix represents the instances in an actual class while each column represents the instances in a predicted class, or vice versa. It is a special kind of contingency table, with two dimensions ("actual" and "predicted"), and identical sets of "classes" in both dimensions (each combination of dimension and class is a variable in the contingency table.) - **Prediction Bias**: The difference between the average of the predicted labels and the average of the labels in the data set. One should check for prediction bias when evaluating the classifier's results. Causes of bias can include: - **Noisy data set**: Errors in original data can as the collection method may have an underlying bias. - **Processing bug**: Errors in the data pipeline can introduce bias. - **Biased training sample (unbalanced samples)**: Model parameters may be skewed towards majority classes. - **Overly strong regularization**: Model may be underfitting model and too simple. - **Proxy variables**: Model features may be highly correlated. - **Overfitting and Underfitting**: Overfitting occurs when the the model built corresponds too closely or exactly to a particular set of data, and thus may fail to fit to predict additional data reliably. An overfitted model is a mathematical model that contains more parameters than can be justified by the data. Underfitting occurs when the model built does adequately capture the patterns in the data. As an example, a linear model will underfit a non-linear dataset. ## Platforms, Tools, or Libraries: - **Python**: - **scikit-learn**: Is a free software machine learning library for Python and includes features for classification. - **TensorFlow**: is an end-to-end source machine learning platform. - **Keras**: is an open-source library that provides a Python API designed to enable fast experimentation with deep neural networks. - **PyTorch**: Is a machine learning framework based on the Torch library. - **R**: - **caret**: Classification And REgression Training package contains functions to streamline model training for complex regression and classification problems. - **randomForest**: Implementation of classification and regression based on forest of trees. ## References 1. Supervised Learning. IBM. [Link](https://www.ibm.com/topics/supervised-learning). 1. Types of Classification in Machine Learning. Machine Learning Mastery. [Link](https://machinelearningmastery.com/types-of-classification-in-machine-learning/). 1. Google. (18 July 2022). Classification: Precision and Recall. [Link](https://developers.google.com/machine-learning/crash-course/classification/precision-and-recall). 1. Wikipedia. (18 Aug 2023). Overfitting. [Link](https://en.wikipedia.org/wiki/Overfitting). 1. Wikipedia. (19 Aug 2023). Confusion matrix. [Link](https://en.wikipedia.org/wiki/Confusion_matrix).
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.
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.
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. 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.
Blocking DNS Network Traffic based on criteria such as IP address, domain name, or DNS query type.
## 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.
Deploying a network resource for the purposes of deceiving an adversary.
## 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.
The eviction tactic is used to remove an adversary from a computer network.
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).
A system call that gets the system time. For POSIX.1 systems, time() invokes a call to get the system time.
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.
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.
## 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).
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.
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).
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.
An access ticket/token issued by a Kerberos system.
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).
A user account on a given host is a local user account for that specific host.
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.
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 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.
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.
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 traffic is network traffic originating from a host of interest (client), to another host (server).
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.]
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.
Simple form of password database held in a single file (e.g., /etc/password)
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.
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).
Preventing execution of any address in a memory region other than the code segment.
## 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 could bypass this defense, as although they may pass attacker-controlled data or stack frames to a function, they abuse functions that are legitimately located in the .text segment (code segment) of the program. For those, more advanced defenses such as a table of valid jump addresses, function call analysis, or return depth analysis could be used.
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.
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.
A function which accesses raw memory, usually using memory addresses.
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.
MagicDraw offers the most robust standards compliant [Unified Architecture Framework (UAF)], DoDAF 2.0, MODAF 1.2, NAF 3, and NAF 4 via a UAF standardized solution. And what's more, No Magic fully supports all architectural framework products ensuring you achieve project results. No Magic also leads the industry in usability and interoprability, ensuring that you avoid unnecessary cost, schedule and performance risk.
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.
## References Supervised Learning. IBM. [Link](https://www.ibm.com/topics/supervised-learning).
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.
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.
## References Wolfram MathWorld. (n.d.). Statistics. [Link](https://mathworld.wolfram.com/Statistics.html)
System Configuration Init Database Record
A database record holding information used to configure the services, parameters, and initial settings for an operating system at startup.
System Configuration Startup Database Record
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.
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.
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.
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.
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)
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.
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.
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.
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)
Validating that server components of a messaging infrastructure are authorized to send a particular message.
## 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 or modified. - Email message authentication does not replace the need to do email content analysis since executables, attachments, or links or other parts of the email beyond the sender domain are not verified.
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.
An action performed by a user. Executing commands, granting permissions, and accessing resources are examples of user actions.
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.
Analyzing the amount of data transferred by a user.
## 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.
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.)
A user logon initialization resource contains information used to configure a user's environment when a user logs into a system.
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.
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.
## References Wikipedia. (n.d.). Statistical dispersion. [Link](https://en.wikipedia.org/wiki/Statistical_dispersion)
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.
Web network traffic is network traffic that uses a standard web protocol.
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.
## 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.
x copies y: An technique or agent x reproduces or makes and exact copy of some digital artifact y.
x manages y: The technique or agent x watches and directs the use of a digital artifact y.
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.
Asset inventorying identifies and records the organization's assets and enriches each inventory item with knowledge about their vulnerabilities.
Cleartext Storage of Sensitive Information
Externally Controlled Reference to a Resource in Another Sphere
Incorrect Provision of Specified Functionality
Improper Check for Unusual or Exceptional Conditions
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.
## 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)
Analyzing database queries to detect [SQL Injection](https://capec.mitre.org/data/definitions/66.html).
## 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.
A Decoy Environment comprises hosts and networks for the purposes of deceiving an attacker.
## 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.
A sensor application installed on a endpoint (platform) to collect information on platform components.
Limiting access to computer input/output (IO) ports to restrict unauthorized devices.
## 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
Analyzing identifier artifacts such as IP address, domain names, or URL(I)s.
Analyzing inbound network session or connection attempt volume.
## 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.
Operating System Configuration Component
An component of the overall information necessary for the configuration of an operating system.
Operating System Configuration Information
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.
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 identifies and models the vulnerabilities of, and risks to, an organization's activities individually and as a whole.
Firmware that is installed on computer peripheral devices.
Comparing the "text" or "code" memory segments to a source of truth.
## 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 defeated by altering the local verification logic. * Verification that is run only on a recurring basis could be evaded if the malicious alteration is completed before verification is run. * Verification that requests an operation to be performed on a subset of the code segment could be evaded by performing that operation on a copy of the relevant bytes of the code segment. * Verification based on a system of record that can be altered may fail if that system of record is modifiable by a malicious user.
Restoring an object for an entity to access. This is the broadest class for object restoral.
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.
Configuring a kernel to use an allow or deny list to filter kernel api calls.
Monitoring system files such as authentication databases, configuration files, system logs, and system executables for modification or tampering.
## 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.
Software services provided as part of the operating system, typically accessed through system calls.
The sub-techniques of this are specific software implementations of scheduling capabilities
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.
A script used to initialize and configure elements of the user's applications and user environment.
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.
date
A point or period of time associated with an event in the lifecycle of the resource.
x deletes y: A technique or agent x wipes out the digitally or magnetically recorded information of digital object y.
x may-add y: They entity x may add the thing y; that is, 'x adds y' may be true.
Modifying an application's configuration to reduce its attack surface.
## 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.
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.
Collecting authorization events, creating a baseline user profile, and determining whether authorization events are consistent with the baseline profile.
## 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.
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Files or Directories Accessible to External Parties
Use of Incorrectly-Resolved Name or Reference
Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
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).
## References Cluster analysis. (n.d.). Wikipedia. [Link](https://en.wikipedia.org/wiki/Cluster_analysis)
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.
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.
Analysis of domain name metadata, including name and DNS records, to determine whether the domain is likely to resolve to an undesirable host.
## 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.
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.
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
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.
Hardware component inventorying identifies and records the hardware items in the organization's architecture.
## 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)
Analyzing standard inter process communication (IPC) protocols to detect deviations from normal protocol activity.
## 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.
BFO, Cyc equiv, SUMO equiv, [Ontology Works] equiv
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:
Using kernel-level capabilities to isolate processes.
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).
A record of events in the order of their occurrence.
Machine learning techniques are computational methods that combine statistics, probability, and optimization to make accurate predictions and/or improve performance.
## References Machine learning." Wikipedia. [Link](https://en.wikipedia.org/wiki/Machine_learning).
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.
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.
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.
An operating system process, or system process, is a process running to perform operating system functions.
Terminating a running application process on a computer system.
## 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 has defined instead of terminating, and the signal SIGKILL forces immediate termination. The related command `xkill` terminates the connection of a program to the X window server, after which the user process may decide to terminate itself; however, termination is not guaranteed as the process, which could be on the same or different host, could then run in a terminal or reconnect to a different X server on any host. Emacs is such a program that would not terminate itself after its connection to the X server is terminated. ## Considerations ### Persistence Mechanisms Terminating a malicious process is not enough to stop an adversary that has already gained persistence in the host via any initial access mechanism, including through that process or another access mechanism. ### Terminating Multiple Processes On most operating systems, process termination operations typically occur independently of each other, without functionality provided to atomically terminate multiple processes. If there are multiple malicious processes which can make system calls to spawn other processes once one of them is closed, user session termination or system restart might be required. ### Process Access Permissions Users must have permissions to kill the process. On Unix-like systems, either root or the process user can kill the process. On Windows systems, process permissions are managed separately via process security tokens. ### Process Resource Handles #### Terminating Processes with Open Resource Handles Processes may have open resource handles, which could leave those resources in an undesired state if the process is forced to terminate. As such, most operating systems provide a means to send a signal to a process to inform it to gracefully terminate, and on most of these operating systems, it is the typical first step used to terminate a process. #### Signal Traps As the process may have open resource handles, commonly-used methods of process termination involve sending a signal to the process to terminate. On Windows, the `ExitProcess()` function is used for this purpose. Process instructions, as well as a third-party DLL can also cause the process to exit. On Linux, the process is sent a signal on the occurrence of various events: when it loses the console, `SIGHUP`; when termination is requested, `SIGTERM`. The processor then redirects execution to the function registered to handle the signal. Therefore, sending a signal to the process to ask it to terminate may not always work. ##### Avoiding Signal Traps On Unix-like systems, sending the `SIGKILL` signal for a process does not send a message to the process or invoke an implementation-defined handler; instead, it immediately does not allow the process to execute any further processor instructions. On Windows `TerminateProcess()` instead of `ExitProcess()` performs the equivalent. #### Hang on System Call Execution Even still, as the operating system kernel manages the processes, kernel code may block process signals, including those which cannot be trapped, and does in certain circumstances. Signals are blocked and queued for the duration of the system call when interrupting the system call would result in a kernel invariant being violated, such as when an action results in a malformed data structure; this blocking is common for filesystem requests. Such system calls can hang when a filesystem has gone offline, leading to a long-term uninterruptible sleep, represented in POSIX command `ps` output as D state. Any malicious system calls or system call handlers are issues of a much larger problem (a kernel-level rootkit) and the system should be redeployed entirely or restored from a backup known to be prior to compromise, and other systems accessible directly and indirectly from that one should also be examined. A process that is truly hung in a system call may prevent the system from shutting down and leave it in an unresponsive state; a hard power off is required. To speed up the action of terminating a process in uninterruptible sleep, the process resource accesses (handles) could be analyzed. On Linux, [`sync` followed by `echo 3 > /proc/sys/vm/drop_caches`](https://www.kernel.org/doc/Documentation/sysctl/vm.txt) is a safe way to free up some inactive resource handles. #### Kernel Processes and Threads The kernel may not allow kernel processes, which are created via methods other than user-space processes, to be terminated. #### Other Code using the Process Terminating a shared library can lead to unexpected errors; such shared libraries have their own mechanisms for termination. On Windows, a DLL is unloaded when the reference count of the library reaches 0. #### Zombie process After a process has been terminated, it may still take up an entry in the operating system process table until another event occurs. ##### Windows In Windows, a process object is deleted when the last handle to the process is closed. ##### Linux In Linux, a process is removed from the process table when it is reaped by its parent process. If the parent terminates, historically the parent has been changed to pid 1; however, in the Linux kernel 3.4 and above, processes can set a different process as the subreaper using the `prctl()` system call. Zombie processes and hung processes could be resolved with a restart of the system. #### System restart Finally a system restart might be required to kill a process. Systems which are only accessible via a remote in-band connection may become inaccessible if a process termination operation that is necessary for reboot does not complete. ### Subsystems Processes that are started in a subsystem might not be fully terminated if they are terminated using the command for that subsystem. For example, in the Windows Subsystem for Linux (WSL), processes started and terminated via WSL calls such as with the `kill` command in Bash may still have an entry in the Windows process table.
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.
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.
## 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)
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.
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.
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)
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.
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.
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.
x blocks y: The entity x blocks off the use of digital artifact y by reference to a block or allow list (or both.)
x loads y: The technique or process x transfers a software from a storage y to a computer's memory for subsequent execution.
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".
x spoofs y: The technique x creates a fake instance of a digital artifact y; that is, y is a decoy, fake, or counterfeit.
Collecting authentication events, creating a baseline user profile, and determining whether authentication events are consistent with the baseline profile.
## 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.
Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Improper Restriction of Communication Channel to Intended Endpoints
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.
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.
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.
## 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](https://cuckoosandbox.org)
A one-time password is valid for only one user authentication.
## 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.
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.
Comparing the cryptographic hash or derivative of a pointer's value to an expected value.
## 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.
Monitoring the activity of remote procedure calls in communication traffic to establish standard protocol operations and potential attacker activities.
## 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.
Analyzing the resources accessed by a user to identify unauthorized activity.
## 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.
Tracking changes to the state or configuration of critical system level processes.
## 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.
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.
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.
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).
x d3fend-annotation y: The d3fend object x has the annotation y.
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.
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.
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.).
Insufficient Adherence to Expected Conventions
Improper Handling of Exceptional Conditions
A Decoy Object is created and deployed for the purposes of deceiving attackers.
## 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.
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.
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.
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'
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.
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).
Analyzing system calls to determine whether a process is exhibiting unauthorized behavior.
## 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. * A model built from a training set of system calls and related data may not be updated fast enough to detect new threats. [1] [Syscalls](http://man7.org/linux/man-pages/man2/syscalls.2.html) [2] [Hooking](http://dbpedia.org/resource/Hooking)
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).
x may-produce y: They entity x may produce the thing y; that is, 'x produces y' may be true.
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.
## 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.
Exposure of Sensitive Information to an Unauthorized Actor
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.
Execution Isolation techniques prevent application processes from accessing non-essential system resources, such as memory, devices, or files.
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.
Network Isolation techniques prevent network hosts from accessing non-essential system network resources.
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.
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.
Reference - Cybersecurity Incident and Vulnerability Response Playbooks
Cybersecurity and Infrastructure Security Agency
Cybersecurity Incident & Vulnerability Response Playbooks
Detection of an unauthorized remote live terminal console session by examining network traffic to a network host.
## 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 resulting in false negatives
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.
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.
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.
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.
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).
Inappropriate Source Code Style or Formatting
Improper Restriction of Operations within the Bounds of a Memory Buffer
Asymmetric Resource Consumption (Amplification)
Improper Check or Handling of Exceptional Conditions
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.
File Analysis is an analytic process to determine a file's status. For example: virus, trojan, benign, malicious, trusted, unauthorized, sensitive, etc.
## 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.
Employing file hash comparisons to detect known malware.
## 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.
Inbound internet traffic is network traffic from a host outside a given network initiated on an incoming connection to a host inside that network.
An operating system configuration file is a file used to configure the operating system.
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 traffic is encrypted network traffic on an outgoing connection initiated from a host within a network to a host outside the network.
Monitoring platform components such as operating systems software, hardware devices, or firmware.
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
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.
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.
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)
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).
## 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)
A weakness is a condition in a software, firmware, hardware, or service component that, under certain circumstances, could contribute to the introduction of vulnerabilities.
d3fend-vendor-registry-data-property
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
Using biological measures in order to authenticate a user.
Requiring a digital certificate in order to authenticate a user.
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.
Cryptographically verifying firmware integrity.
## 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
Preventing one process from writing to the memory space of another process through hardware based address manager implementations.
## 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
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.
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.
x authenticates y: The subject x establishes the authenticity of some y. This relation indicates an authentication event has occurred.
Information about what access permissions are granted to particular users for particular objects
A resource used to configure a system including software and hardware.
Encrypting a hard disk partition to prevent cleartext access to a file system.
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.
An operating system file is a file that is part of, or used to store information about, the operating system itself.
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**.
## 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
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.
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.
x monitors y: The technique or agent x keep tabs on; keeps an eye on; or keep the digital artifact y under surveillance.
x restricts y: An entity x bounds the use of entity y.
Insufficient Verification of Data Authenticity
The detect tactic is used to identify adversary access to or unauthorized activity on computer networks.
Monitoring the existence of or changes to Domain User Accounts.
Employing a pattern matching rule language to analyze the content of files.
## 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
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]
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.
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.
A reference used to develop KB articles.
Credential Hardening techniques modify system or network properties in order to protect system or network/domain credentials.
Using a digital signature to authenticate a file before opening.
## 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.
Encrypting a file using a cryptographic key.
## 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.
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.
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)
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.
## 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.
Ensuring the integrity of drivers loaded during initialization of the operating system.
## 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.
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).
Modifying system configuration to increase password strength.
## 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.
Information used to configure the parameters and initial settings for an application.
Restricting inter-domain trust by modifying domain configuration.
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.
Intranet administrative network traffic is administrative network traffic that does not cross a given network's boundaries and uses a standard administrative protocol.
Restricting access to a local file by configuring operating system functionality.
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.
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.
## 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.
Replacing old software on a computer system component.
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.
x executes y: The subject x takes the action of carrying out (executing) y, which is a single software module, function, or instruction.
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).
Improper Neutralization of Special Elements
Encrypted encapsulation of routable network traffic.
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.
Intranet network traffic is network traffic traversing that does not traverse a given network's boundaries.
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.
Improper Following of Specification by Caller
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.
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.
Requiring proof of two or more pieces of evidence in order to authenticate a user.
## 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.
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.
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.
Blocking the execution of files on a host in accordance with defined application policy rules.
## 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.
Generic function that receives direct user input from an untrusted source.
x may-create y: They entity x may create the entity y; that is, 'x creates y' may be true.
Analyzing local user accounts to detect unauthorized activity.
The process of temporarily disabling user accounts on a system or domain.
## 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
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.
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
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.
x may-be-associated-with y: The subject x and object y may be associated in some way.
A request-response comprising a user credential presentation to a system and a verification response.
x may-access y: They entity x may access the thing y; that is, 'x accesses y' may be true.
An email, or email message, is a document that is sent between computer users across computer networks.
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.
A database used to hold system configuration data.
x may-invoke y: They entity x may invoke the thing y; that is, 'x invokes y' may be true.
Improper Control of a Resource Through its Lifetime
Process segments are distinct partitions of the memory space of a running process. Heap, data, code, and stack segments are examples of process segments.
D3FEND things are concepts defined in the core D3FEND Framework.
Indirect System calls are made through an OS-specific library (like glibc in Linux) that provides a higher-level API for the system calls.
Restricting system configuration modifications to a specific user or group of users.
A method which makes a computer system more difficult to attack.
Analyzing intercepted or summarized computer network traffic to detect unauthorized activity.
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
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
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.
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.
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.
Outbound internet network traffic is network traffic on an outgoing connection initiated from a host within a network to a host outside the network.
to potentially have as contents or constituent parts; comprise; include.
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.
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
Analyzing spawn arguments or attributes of a process to detect processes that are unauthorized.
## 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.
A database record holding information used to configure the services, parameters, and initial settings for an operating system.
Restricting a user account's access to resources.
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.
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.
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.
Restricting network traffic originating from a private host or enclave destined towards untrusted networks.
## 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)
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.
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.
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.
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.
Restricting network traffic originating from untrusted networks destined towards a private host or enclave.
## 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)
x may-modify y: They entity x may modify the thing y; that is, 'x modifies y' may be true.
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.
Controlling access to local computer system resources with kernel-level capabilities.
## How it works Mandatory access control 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 MAC implementations #### Security label access control A fine-grained form of mandatory access 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 MAC 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 MAC 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 together this type of access control is typically employed to ensure true isolation of processes and VMs. #### File path level controls A less fine-grained form of mandatory access control is to apply security labels that allow for access control at the file path level. Access control is filesystem agnostic and no relabeling of resources is required. Pathname access control usually seems more natural for implementation and corresponding access audits. This type of MAC is what is employed in AppArmor [3]. AppArmor was developed to provide a simpler alternative MAC method with much less management overhead. A simple access policy is maintained that defines path resource access rules. Access control attributes are typically associated with programs instead of users. ## Considerations Some implementations of security label mandatory access control contain complex rules set that are hard to verify and complex to maintain over time. Initial planning of access model and continuous monitoring of the available users, resources and object is necessary. ## Implementations * Linux C-Groups, and policy engines like SELinux and AppArmor * Windows Mandatory Integrity Control introduced in Windows Vista ### Citations 1. [Implementation of Mandatory Access Control in Distributed Systems](https://link.springer.com/article/10.3103/S0146411618080357) 2. [SELinux](https://selinuxproject.org/) 3. [AppArmor](https://www.apparmor.net/)
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-'.)
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.)
A file maintained in computer-readable form.
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.
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.
Defense Information Systems Agency (DISA) Field Security Office (FSO)