Sigma rule: CMSTP UAC Bypass via COM Object Access

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-2e8d57477a4d, updated 2024-12-01T00:00:00.000Z.

Rule

Title
CMSTP UAC Bypass via COM Object Access
Status
stable
Level
high
Author
Nik Seetharaman, Christian Burkard (Nextron Systems)
Date
2019-07-31
Modified
2024-12-01
File
rules/windows/process_creation/proc_creation_win_uac_bypass_cmstp_com_object_access.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects UAC Bypass Attempt Using Microsoft Connection Manager Profile Installer Autoelevate-capable COM Objects (e.g. UACMe ID of 41, 43, 58 or 65)

Log source

product
windows
category
process_creation

Detection

selection:
    ParentImage|endswith: '\DllHost.exe'
    ParentCommandLine|contains:
        - ' /Processid:{3E5FC7F9-9A51-4367-9063-A120244FBEC7}' # cmstplua.dll
        - ' /Processid:{3E000D72-A845-4CD9-BD83-80C07C3B881F}' # CMLUAUTIL
        - ' /Processid:{BD54C901-076B-434E-B6C7-17C531F4AB41}' # EditionUpgradeManagerObj.dll
        - ' /Processid:{D2E7041B-2927-42FB-8E9F-7CE93B6DC937}' # colorui.dll
        - ' /Processid:{E9495B87-D950-4AB5-87A5-FF6D70BF3E90}' # wscui.cpl
    IntegrityLevel:
        - 'High'
        - 'System'
        - 'S-1-16-16384' # System
        - 'S-1-16-12288' # High
condition: selection

False positives (as the rule lists them)

  • Legitimate CMSTP use (unlikely in modern enterprise environments)

Tags

  • attack.execution
  • attack.privilege-escalation
  • attack.stealth
  • attack.t1548.002
  • attack.t1218.003
  • attack.g0069
  • car.2019-04-001

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/process_creation/proc_creation_win_uac_bypass_cmstp_com_object_access.yml

Sources and licences

  • SigmaHQ

    "CMSTP UAC Bypass via COM Object Access" by Nik Seetharaman, Christian Burkard (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_uac_bypass_cmstp_com_object_access.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: CMSTP UAC Bypass via COM Object Access",
entity page, dataset version ref-2e8d57477a4d, updated 2024-12-01T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/4b60e6f2-bf39-47b4-b4ea-398e33cfe253 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 4b60e6f2-bf39-47b4-b4ea-398e33cfe253, 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.