huntrule

Windows Process Creation: nimgrab.exe Execution (Nim Tool Download Behavior)

Alerts on execution of nimgrab.exe on Windows when hashes match known indicators.

FreeReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
frack113 (SigmaHQ), DRL 1.1
Published
2022-08-28
Updated
2026-07-30
AnalysisDetection

ATT&CK techniques

C2

  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 events where the executable name ends with \nimgrab.exe and the file matches specified hash indicators (MD5, SHA256, and IMPHASH). Attackers may use nimgrab to download additional payloads, aligning with command-and-control related staging behavior. The detection relies on process execution telemetry and file hash values to confirm the binary.

Reporting behind it

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Suspicious Certutil Download and Certificate Installation via Living-off-the-Land
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Windows Process Creation: nimgrab.exe Execution (Nim Tool Download Behavior)
Pivot detection · T1105 · 9 related

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