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Windows rundll32 Loading Renamed comsvcs.dll via DLL Image Load

Flags rundll32.exe loading a renamed comsvcs.dll module consistent with process memory dumping behavior on Windows.

FreeReviewedSigma · High · v2
Product
windows
Category
image_load
Author
Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2022-08-14
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Cred Access

  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 executions where rundll32.exe loads a DLL image that ends with \comsvcs.dll when the loaded image is not an expected comsvcs.dll location/pattern. Loading comsvcs.dll through rundll32 is a common technique attackers use to access memory-related capabilities under a living-off-the-land binary. It relies on Windows image-load telemetry that records the launching Image and the ImageLoaded path, along with matching IMPHASH values for rundll32.exe.

Reporting behind it

Related detections9 linkedT1003.001 — drag to rearrange
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Malicious LSASS Credential Dump via ProcDump (via process_creation)
Malicious LSASS Memory Dump via comsvcs.dll by Salt Typhoon
Malicious LSASS Dump via Process Access (via process_access)
Malicious LSASS Credential Dump with LSASSY - Process (via process_creation)
Malicious LSASS Credential Dump with LSASSY - Admin Share (via security)
Malicious Task Manager Used for LSASS Dump - Kernel (via security)
Windows rundll32 Loading Renamed comsvcs.dll via DLL Image Load
Pivot detection · T1003.001 · 9 related

Changelog

v2
  1. v2
    Candidate ingested via manual entry.2026-07-31
  2. 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.