PowerShell for SecOps

PowerShell MITRE-Based Incident Investigations

PowerShell is a powerful and versatile tool deeply integrated into the Windows operating system. It is a critical component in legitimate administrative tasks and malicious activities. For this reason, it plays a significant role in MITRE ATT&CK-based investigations, where adversary tactics, techniques, and procedures (TTPs) are analysed to understand and combat cyber threats.

The MITRE ATT&CK framework provides a comprehensive matrix of adversary behaviours, detailing how attackers exploit tools like PowerShell to achieve objectives such as privilege escalation, lateral movement, persistence, and data exfiltration. PowerShell’s extensive capabilities, including remote execution, automation, and interaction with Windows APIs, make it a favoured tool among attackers to execute malicious scripts stealthily.

For DFIR analysts, PowerShell investigations aligned with the MITRE ATT&CK framework help to identify and correlate specific techniques used during an attack. Examples include detecting command-line obfuscation (T1059.001), analysing script execution (T1569.002), and investigating scheduled tasks (T1053.005). By focusing on these techniques, analysts can uncover traces of attacker activity, map the kill chain, and develop a comprehensive understanding of the breach.

PowerShell’s dual nature as both an operational necessity and a security risk emphasises the importance of a structured, framework-driven approach to its investigation. Leveraging MITRE-based methodologies, DFIR professionals can systematically detect malicious use of PowerShell, implement targeted defences, and enhance an organisation’s security posture against advanced threats.

This section will cover the following areas with their dedicated subsections:

Powershell Remoting

Reconnaissance Discovery

Initial Access Discovery

Execution Discovery

Persistence Discovery

Privilege Escalation Discovery

Defence Evasion Discovery

Credential Access Discovery

Discovery

Lateral Movement Discovery

Collection Discovery

Command & Control (C2) Discovery

Exfiltration Discovery

Impact Discovery

Benefits of Using PowerShell

1. Comprehensive System Visibility: PowerShell provides deep visibility into Windows systems, enabling analysts to query, collect, and analyse data directly from endpoints. It supports inspecting processes, services, registry entries, event logs, and more, aligning well with tactics and techniques outlined in the MITRE ATT&CK framework.

2. Automation and Efficiency: PowerShell scripts can automate repetitive investigation tasks, such as extracting artifacts, searching for indicators of compromise (IOCs), or correlating data from multiple sources. This reduces manual effort and speeds up the investigation process.

3. Alignment with MITRE ATT&CK: PowerShell is effective in detecting and investigating many ATT&CK techniques, such as:

   • Execution (T1059.001): Monitoring suspicious PowerShell commands.

   • Credential Dumping (T1003): Identifying tools or techniques used to extract credentials.

   • Persistence (T1547): Inspecting startup scripts, scheduled tasks, or registry entries.

4. Integration with SecOps Tools: PowerShell integrates seamlessly with incident response and SecOps tools like Microsoft Defender, Sysinternals, and Azure Sentinel, enabling analysts to gather forensic data or execute response actions (e.g., isolating a machine, killing malicious processes).

5. Remote Investigation Capability: Using PowerShell Remoting (WinRM), SecOps teams can investigate and respond to incidents on remote systems, making it a powerful tool for large, distributed environments.

6. Custom Detection Rules: PowerShell scripts can be tailored to detect specific TTPs or behaviours identified in MITRE, such as command-line obfuscation or encoded payloads.

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Requirements

1. Knowledge and Skills:

   • Proficiency in PowerShell scripting and familiarity with the MITRE ATT&CK framework.

   • Understanding Windows internals (e.g., registry, services, processes, event logs).

2. Proper Permissions:

   • Administrative privileges may be required for specific tasks, such as accessing system logs, inspecting services, or collecting forensic artifacts.

3. Endpoint Configuration:

   • PowerShell Logging: Enable detailed logging (Module Logging, Script Block Logging, and Transcription) to capture suspicious activities for investigation.

   • WinRM Configuration: Ensure that PowerShell Remoting is configured securely for remote investigations.

4. Security Tools Integration:

   • Integration with tools like Microsoft Defender for Endpoint, Azure Sentinel, or SIEM solutions to fetch logs, detect alerts, or automate investigations.

5. Safe Execution Environment:

   • Use a hardened administrative workstation to execute PowerShell commands to prevent tampering or compromise.

   • Deploy execution policies and code-signing practices to restrict the execution of untrusted scripts.

6. Incident Response Playbooks:

   • Develop PowerShell-based playbooks for key SecOps tasks, such as process enumeration, IOC hunting, or network connection analysis, aligned with MITRE techniques.

7. Monitoring and Alerts:

   • Implement monitoring for potentially malicious use of PowerShell, such as encoded commands, obfuscated scripts, or invocation of suspicious modules.

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By effectively leveraging PowerShell, SecOps teams can significantly enhance their capability to detect, investigate, and respond to threats in accordance with the MITRE ATT&CK framework.