Sigma rule: Microsoft Defender Blocked from Loading Unsigned DLL

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-ebab4ebc6cac, updated 2022-09-28T00:00:00.000Z.

Rule

Title
Microsoft Defender Blocked from Loading Unsigned DLL
Status
test
Level
high
Author
Bhabesh Raj
Date
2022-08-02
Modified
2022-09-28
File
rules/windows/builtin/security_mitigations/win_security_mitigations_defender_load_unsigned_dll.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects Code Integrity (CI) engine blocking Microsoft Defender's processes (MpCmdRun and NisSrv) from loading unsigned DLLs which may be an attempt to sideload arbitrary DLL

Log source

product
windows
service
security-mitigations

Detection

selection:
    EventID:
        - 11
        - 12 # MDE: ExploitGuardNonMicrosoftSignedBlocked
    ProcessPath|endswith:
        - '\MpCmdRun.exe'
        - '\NisSrv.exe'
condition: selection

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.privilege-escalation
  • attack.persistence
  • attack.execution
  • attack.stealth
  • attack.t1574.001

MITRE ATT&CK ids this rule names

References

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/builtin/security_mitigations/win_security_mitigations_defender_load_unsigned_dll.yml

Sources and licences

  • SigmaHQ

    "Microsoft Defender Blocked from Loading Unsigned DLL" by Bhabesh Raj (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/builtin/security_mitigations/win_security_mitigations_defender_load_unsigned_dll.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Microsoft Defender Blocked from Loading Unsigned DLL",
entity page, dataset version ref-ebab4ebc6cac, updated 2022-09-28T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/0b0ea3cc-99c8-4730-9c53-45deee2a4c86 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 0b0ea3cc-99c8-4730-9c53-45deee2a4c86, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.