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.
While User Execution frequently occurs shortly after Initial Access it may occur at other phases of an intrusion, such as when an adversary places a file in a shared directory or on a user's desktop hoping that a user will click on it. This activity may also be seen shortly after Internal Spearphishing.
Adversaries may also deceive users into performing actions such as:
For example, tech support scams can be facilitated through Phishing, vishing, or various forms of user interaction. Adversaries can use a combination of these methods, such as spoofing and promoting toll-free numbers or call centers that are used to direct victims to malicious websites, to deliver and execute payloads containing malware or Remote Access Tools.(Citation: Telephone Attack Delivery)
User Execution – multi-surface behavior chain (documents/links → helper/unpacker → LOLBIN/child → egress)
User Training: User Training involves educating employees and contractors on recognizing, reporting, and preventing cyber threats that rely on human interaction, such as phishing, social engineering, and other manipulative techniques. Comprehensive training programs create a human firewall by empowering users to be an active component of the organization's cybersecurity defenses. This mitigation can be implemented through the following measures:
Create Comprehensive Training Programs:
Use Simulated Exercises:
Leverage Gamification and Engagement:
Incorporate Security Policies into Onboarding:
Regular Refresher Courses:
Emphasize Real-World Scenarios:
Execution Prevention: Prevent the execution of unauthorized or malicious code on systems by implementing application control, script blocking, and other execution prevention mechanisms. This ensures that only trusted and authorized code is executed, reducing the risk of malware and unauthorized actions. This mitigation can be implemented through the following measures:
Application Control:
New-AppLockerPolicy -PolicyType Enforced -FilePath "C:\Policies\AppLocker.xml")Script Blocking:
Set-ExecutionPolicy AllSigned)Executable Blocking:
%TEMP% or %APPDATA% directories..exe, .bat, or .ps1 files from user-writable directories.Dynamic Analysis Prevention:
Behavior Prevention on Endpoint: Behavior Prevention on Endpoint refers to the use of technologies and strategies to detect and block potentially malicious activities by analyzing the behavior of processes, files, API calls, and other endpoint events. Rather than relying solely on known signatures, this approach leverages heuristics, machine learning, and real-time monitoring to identify anomalous patterns indicative of an attack. This mitigation can be implemented through the following measures:
Suspicious Process Behavior:
Unauthorized File Access:
Abnormal API Calls:
OpenProcess and WriteProcessMemory and terminates the offending process.Exploit Prevention:
Restrict Web-Based Content: Restricting web-based content involves enforcing policies and technologies that limit access to potentially malicious websites, unsafe downloads, and unauthorized browser behaviors. This can include URL filtering, download restrictions, script blocking, and extension control to protect against exploitation, phishing, and malware delivery. This mitigation can be implemented through the following measures:
Deploy Web Proxy Filtering:
Enable DNS-Based Filtering:
Enforce Content Security Policies (CSP):
Control Browser Features:
Monitor and Alert on Web-Based Threats:
Network Intrusion Prevention: Use intrusion detection signatures to block traffic at network boundaries.
Limit Software Installation: Prevent users or groups from installing unauthorized or unapproved software to reduce the risk of introducing malicious or vulnerable applications. This can be achieved through allowlists, software restriction policies, endpoint management tools, and least privilege access principles. This mitigation can be implemented through the following measures:
Application Whitelisting
Restrict User Permissions
Software Restriction Policies (SRP)
%AppData%, %Temp%, and external drives..exe, .bat, .msi, .js, .vbs) to trusted directories only.Endpoint Management Solutions
Monitor Software Installation Events
Implement Software Inventory Management
Tools for Implementation
Application Whitelisting:
Endpoint Management:
Software Restriction Policies:
Monitoring and Logging:
Inventory Management and Auditing: