huntrule

Windows: CertOC.exe Loading a DLL from User-Writable Paths via -LoadDLL

Alerts on CertOC.exe using -LoadDLL with DLLs from temp/user-writable directories on Windows.

FreeReviewedSigma · High · v2
Product
windows
Category
process_creation
Author
Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2023-02-15
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Defense Evasion

  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 identifies executions of CertOC.exe where the command line includes the -LoadDLL argument and the target DLL is referenced from common user-writable or staging locations. Using CertOC.exe to load a DLL can support stealthy execution by proxying library loads through a signed Microsoft-signed utility. The detection relies on Windows process creation telemetry, specifically the process image/original file name, the command line containing -LoadDLL, and the presence of suspicious file paths in the command line.

Reporting behind it

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Windows: CertOC.exe Loading a DLL from User-Writable Paths via -LoadDLL
Pivot detection · T1218 · 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.