huntrule

Windows: Rundll32 Executing Registered COM Local Servers via Command-Line { }

Flags rundll32.exe launching COM local servers using -sta/-localserver with braced arguments.

FreeReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
frack113 (SigmaHQ), DRL 1.1
Published
2022-02-13
Updated
2026-07-30
AnalysisDetection

ATT&CK techniques

Persistence → 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 matches process executions of rundll32.exe where the command line includes COM local server startup flags (-sta and -localserver) and contains a braced argument ({ ... }). Attackers can use rundll32 to load functionality indirectly through registered COM objects, which can aid persistence and privilege escalation. The detection relies on Windows process creation telemetry fields for Image/OriginalFileName and command-line content.

Reporting behind it

Related detections9 linkedT1546.015 — drag to rearrange
Suspicious COM Hijack of ClickOnce Deployment Service CLSID (via registry_set)
Suspicious COM Hijack Via InprocServer32 Modification
Malicious COM Hijacking via TinyTurla CLSID InprocServer32 (via registry_set)
Suspicious dllhost.exe Spawned with CLSID and Anomalous Parent (via process_creation)
Suspicious COM Handler Hijack of MsCtfMonitor CLSID via CharmingCypress
Malicious COM Hijack of PSFactoryBuffer InprocServer32
Malicious APT-C-60 COM Hijack via SpyGlace CLSID InProcServer32 (via registry_set)
Malicious COM Hijack via CLSID InProcServer32 Registry Modification (via registry_set)
Malicious COM Object Hijack Pointing to a User-Writable DLL (via registry_set)
Windows: Rundll32 Executing Registered COM Local Servers via Command-Line { }
Pivot detection · T1546.015 · 9 related

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