Detect Living Off the Land Binaries (LOLBins/LOLBAS) abuse including certutil, regsvr32, mshta, and rundll32 via process telemetry, Sigma rules, and parent-child process analysis with Sysmon endpoint data. Use when hunting for adversaries abusing built-in Windows binaries to download, execute, or proxy malicious code while evading traditional executable-based detection.
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Use detecting-living-off-the-land-with-lolbas to analyze [authorized Sysmon or Windows 4688 telemetry] in [SIEM] and produce prioritized LOLBin detections with Sigma rules and MITRE ATT&CK mapping.
Required inputs
[authorized Sysmon or Windows 4688 telemetry]
[SIEM]
User-approved starter prompt based on a pinned source version; check current skill requirements before running. Task evidence ↗
SKILL.md
name: detecting-living-off-the-land-with-lolbasdescription: Detect Living Off the Land Binaries (LOLBins/LOLBAS) abuse including certutil, regsvr32, mshta, and rundll32 via process telemetry, Sigma rules, and parent-child process analysis with Sysmon endpoint data. Use when hunting for adversaries abusing built-in Windows binaries to download, execute, or proxy malicious code while evading traditional executable-based detection.domain: cybersecuritysubdomain: threat-detectiontags: - lolbas- lolbins- sigma-rules- process-monitoring- sysmon- endpoint-detection- threat-huntingversion: '1.0'author: mahipallicense: Apache-2.0d3fend_techniques: - Executable Denylisting- Execution Isolation- File Metadata Consistency Validation- Application Protocol Command Analysis- Content Format Conversionnist_csf: - DE.CM-01- DE.AE-02- DE.AE-06- ID.RA-05mitre_attack: - T1078- T1190- T1059
Detecting Living Off the Land with LOLBAS
Overview
Living Off the Land Binaries, Scripts, and Libraries (LOLBAS) are legitimate system utilities abused by attackers to execute malicious actions while evading detection. This skill covers detecting abuse of certutil.exe, regsvr32.exe, mshta.exe, rundll32.exe, msbuild.exe, and other LOLBins using process telemetry from Sysmon and Windows Event Logs, combined with Sigma rule-based detection.
When to Use
When investigating security incidents that require detecting living off the land with lolbas
When building detection rules or threat hunting queries for this domain
When SOC analysts need structured procedures for this analysis type
When validating security monitoring coverage for related attack techniques
Prerequisites
Sysmon or Windows Security Event Log (Event ID 4688) with command-line logging enabled
Sigma rule conversion tool (sigmac or sigma-cli)
SIEM platform (Splunk, Elastic, or similar) for log ingestion
Python 3.8+ with pySigma library
LOLBAS project reference database
Steps
Establish LOLBin Watchlist — Build a prioritized list of monitored binaries (certutil, mshta, regsvr32, rundll32, msbuild, installutil, cmstp, wmic, bitsadmin)
Collect Process Telemetry — Ingest Sysmon Event ID 1 (Process Create) and Windows 4688 events with full command-line capture
Build Sigma Detection Rules — Create Sigma rules matching suspicious command-line arguments, network activity, and parent-child process anomalies for each LOLBin
Analyze Parent-Child Relationships — Flag unexpected parent processes spawning LOLBins (e.g., Excel spawning certutil, Word spawning mshta)
Score and Prioritize Alerts — Apply risk scoring based on argument anomaly, parent process, execution path, and network indicators
Generate Detection Report — Produce a structured report of all LOLBin abuse detections with MITRE ATT&CK mapping
Expected Output
JSON report listing detected LOLBin abuse events with severity scores
MITRE ATT&CK technique mapping for each detection (T1218, T1105, T1140, T1127)