Sigma rule: DllUnregisterServer Function Call Via Msiexec.EXE

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-2d5d5c2b32c2, updated 2026-10-19T00:00:00.000Z.

Rule

Title
DllUnregisterServer Function Call Via Msiexec.EXE
Status
test
Level
medium
Author
frack113
Date
2022-04-24
Modified
2026-10-19
File
rules/windows/process_creation/proc_creation_win_msiexec_dll.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects MsiExec loading a DLL and calling its DllUnregisterServer function

Log source

product
windows
category
process_creation

Detection

selection_img:
    - Image|endswith: '\msiexec.exe'
    - OriginalFileName: '\msiexec.exe'
selection_cli:
    CommandLine|contains|windash: ' -z '
    CommandLine|contains: '.dll'
filter_optional_msihandler:
    CommandLine|endswith: '\MsiExec.exe" /Z "C:\Windows\CCM\MsiHandler.dll"'
condition: all of selection_* and not 1 of filter_optional_*

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.stealth
  • attack.t1218.007

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/process_creation/proc_creation_win_msiexec_dll.yml

Sources and licences

  • SigmaHQ

    "DllUnregisterServer Function Call Via Msiexec.EXE" by frack113 (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_msiexec_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: DllUnregisterServer Function Call Via Msiexec.EXE",
entity page, dataset version ref-2d5d5c2b32c2, updated 2026-10-19T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/84f52741-8834-4a8c-a413-2eb2269aa6c8 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 84f52741-8834-4a8c-a413-2eb2269aa6c8, 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.