huntrule

Windows Registry COM Hijacking via scrobj.dll InprocServer32(Default) Persistence

Alerts on registry modifications setting InprocServer32(Default) to scrobj.dll, indicating possible COM hijacking persistence.

FreeReviewedSigma · Medium · v1
Product
windows
Category
registry_set
Author
frack113 (SigmaHQ), DRL 1.1
Published
2022-08-20
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 flags registry changes where the COM in-proc server for the default value is set to C:\WINDOWS\system32\scrobj.dll under an InprocServer32\(Default) target. COM Hijacking is a common persistence technique because it can redirect how Windows loads and instantiates COM components. The detection relies on registry set telemetry that captures the TargetObject ending pattern and the specific Details value pointing to scrobj.dll.

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 Registry COM Hijacking via scrobj.dll InprocServer32(Default) Persistence
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.