Analyzing PowerShell Empire Artifacts

Overview

PowerShell Empire is a post-exploitation framework consisting of listeners, stagers, and agents. Its artifacts leave detectable traces in Windows event logs, particularly PowerShell Script Block Logging (Event ID 4104) and Module Logging (Event ID 4103). This skill analyzes event logs for Empire's default launcher string (powershell -noP -sta -w 1 -enc), Base64 encoded payloads containing System.Net.WebClient and FromBase64String, known module invocations (Invoke-Mimikatz, Invoke-Kerberoast, Invoke-TokenManipulation), and staging URL patterns.

Prerequisites

• Python 3.9+ with access to Windows Event Log or exported EVTX files
• PowerShell Script Block Logging (Event ID 4104) enabled via Group Policy
• Module Logging (Event ID 4103) enabled for comprehensive coverage

Key Detection Patterns

1. Default launcher — powershell -noP -sta -w 1 -enc followed by Base64 blob
2. Stager indicators — System.Net.WebClient, DownloadData, DownloadString, FromBase64String
3. Module signatures — Invoke-Mimikatz, Invoke-Kerberoast, Invoke-TokenManipulation, Invoke-PSInject, Invoke-DCOM
4. User agent strings — default Empire user agents in HTTP listener configuration
5. Staging URLs — /login/process.php, /admin/get.php and similar default URI patterns

Output

JSON report with matched IOCs, decoded Base64 payloads, timeline of suspicious events, MITRE ATT&CK technique mappings, and severity scores.

Verification Criteria

Confirm successful execution by validating:

• [ ] All prerequisite tools and access requirements are satisfied
• [ ] Each workflow step completed without errors
• [ ] Output matches expected format and contains expected data
• [ ] No security warnings or misconfigurations detected
• [ ] Results are documented and evidence is preserved for audit

Compliance Framework Mapping

This skill supports compliance evidence collection across multiple frameworks:

• SOC 2: CC7.2 (Anomaly Detection), CC7.3 (Incident Identification)
• ISO 27001: A.12.4 (Logging & Monitoring), A.16.1 (Security Incident Management)
• NIST 800-53: SI-4 (System Monitoring), IR-4 (Incident Handling), RA-5 (Vulnerability Scanning)
• NIST CSF: DE.AE (Anomalies & Events), DE.CM (Continuous Monitoring), DE.DP (Detection Processes)

Claw GRC Tip: When this skill is executed by a registered agent, compliance evidence is automatically captured and mapped to the relevant controls in your active frameworks.

Deploying This Skill with Claw GRC

Agent Execution

Register this skill with your Claw GRC agent for automated execution:

# Install via CLI
npx claw-grc skills add analyzing-powershell-empire-artifacts

# Or load dynamically via MCP
grc.load_skill("analyzing-powershell-empire-artifacts")

Audit Trail Integration

When executed through Claw GRC, every step of this skill generates tamper-evident audit records:

• SHA-256 chain hashing ensures no step can be modified after execution
• Evidence artifacts (configs, scan results, logs) are automatically attached to relevant controls
• Trust score impact — successful execution increases your agent's trust score

Continuous Compliance

Schedule this skill for recurring execution to maintain continuous compliance posture. Claw GRC monitors for drift and alerts when re-execution is needed.