Hunting for Registry Run Key Persistence

Overview

Registry Run keys (T1547.001) are one of the most commonly used persistence mechanisms by adversaries. When a program is added to a Run key in the Windows registry, it executes automatically when a user logs in. Attackers abuse keys under HKLM\Software\Microsoft\Windows\CurrentVersion\Run, HKCU\Software\Microsoft\Windows\CurrentVersion\Run, and their RunOnce counterparts to maintain persistence. Sysmon Event ID 13 (RegistryEvent - Value Set) captures registry value modifications including the target object path, the process that made the change, and the new value. Detection involves monitoring these events for suspicious executables in temp directories, encoded PowerShell commands, LOLBin paths, and processes that do not normally create Run key entries. Chaining Event 13 with Event 1 (Process Creation) and Event 11 (FileCreate) strengthens detection by confirming payload creation and execution.

Prerequisites

• Windows systems with Sysmon installed and configured to log Event ID 13
• Sysmon config with RegistryEvent rules for Run/RunOnce keys
• Python 3.9+ with json, xml.etree.ElementTree, re modules
• SIEM or log aggregator collecting Sysmon logs (Splunk, Elastic, Sentinel)
• Knowledge of legitimate auto-start programs for baseline comparison

Steps

1. Collect Sysmon Event ID 13 logs filtered for Run/RunOnce key paths
2. Parse event XML/JSON for TargetObject, Details (value written), Image (modifying process)
3. Flag entries where the value points to temp directories, AppData, or ProgramData
4. Detect encoded PowerShell commands or script interpreters in registry values
5. Identify LOLBin abuse (mshta.exe, rundll32.exe, regsvr32.exe, wscript.exe)
6. Compare against known-good baseline of legitimate auto-start entries
7. Check if the modifying process (Image) is unusual (cmd.exe, powershell.exe, python.exe)
8. Chain with Event ID 1 to verify if the registered binary was recently created
9. Generate detection report with MITRE ATT&CK mapping and severity scores
10. Produce Sigma/Splunk detection rules from findings

Expected Output

A JSON report listing suspicious Run key entries with the registry path, value written, modifying process, timestamp, MITRE technique mapping, severity rating, and recommended Sigma detection rules.

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 hunting-for-registry-run-key-persistence

# Or load dynamically via MCP
grc.load_skill("hunting-for-registry-run-key-persistence")

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.