huntrule

Potential BearLPE Exploitation via Windows Task Scheduler schtasks.exe DACL Change

Flags schtasks.exe executions with /change, /TN, /RU, and /RP, consistent with task modification tied to BearLPE attempts.

FreeReviewedSigma · High · v5
Product
windows
Category
process_creation
Author
Olaf Hartong (SigmaHQ), DRL 1.1
Published
2019-05-22
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Execution → Priv Esc

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule flags Windows process creation where schtasks.exe is invoked with command-line arguments that indicate changing a scheduled task and configuring it to run as a specified user with a specified password. The combination of /change, /TN, /RU, and /RP is used to modify task settings in a way that can be leveraged for privilege escalation attempts consistent with BearLPE exploitation activity. Telemetry required is Windows process creation events including the process image name and full command line.

Reporting behind it

Related detections9 linkedT1053.005 — drag to rearrange
Suspicious Scheduled Task Persistence Named SchedulerLsass via schtasks (via process_creation)
Malicious SYSTEM Persistence via Scheduled Task Running rundll32 at Startup (via process_creation)
Suspicious Per-Minute SYSTEM Scheduled Task With Highest Privileges
Suspicious Scheduled Task Executing Rundll32 DLL Export by Ordinal
Suspicious Scheduled Task CacheTask Reconfigured to Run as SYSTEM
Malicious NodeSnake RAT Persistence via Scheduled Task and Node.js (via process_creation)
Malicious Scheduled Task Masquerading as Windows Defender Sync via schtasks (via process_creation)
Suspicious Scheduled Task Creation Launching mshta via schtasks (via process_creation)
Suspicious Service or Task Named windowsinspectionupdate (via process_creation)
Potential BearLPE Exploitation via Windows Task Scheduler schtasks.exe DACL Change
Pivot detection · T1053.005 · 9 related

Changelog

v5
  1. v5
    Candidate ingested via manual entry.2026-07-31
  2. v4
    Candidate ingested via manual entry.2026-07-31
  3. v3
    Candidate ingested via manual entry.2026-07-31
  4. v2
    Candidate ingested via manual entry.2026-07-31
  5. v1
    No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.