Detectionhightest

Bypass UAC via CMSTP

Detect commandline usage of Microsoft Connection Manager Profile Installer (cmstp.exe) to install specially formatted local .INF files

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Launch
E.M. Anhaus (originally from Atomic Blue Detections, Endgame), oscd.communityCreated Thu Oct 24Updated Tue Aug 30e66779cc-383e-4224-a3a4-267eeb585c40windows
Log Source
WindowsProcess Creation
ProductWindows← raw: windows
CategoryProcess Creation← raw: process_creation

Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.

Detection Logic
Detection Logic2 selectors
detection:
    selection_img:
        - Image|endswith: '\cmstp.exe'
        - OriginalFileName: 'CMSTP.EXE'
    selection_cli:
        CommandLine|contains:
            - '/s'
            - '-s'
            - '/au'
            - '-au'
            - '/ni'
            - '-ni'
    condition: all of selection*
False Positives

Legitimate use of cmstp.exe utility by legitimate user

Rule Metadata
Rule ID
e66779cc-383e-4224-a3a4-267eeb585c40
Status
test
Level
high
Type
Detection
Created
Thu Oct 24
Modified
Tue Aug 30
Path
rules/windows/process_creation/proc_creation_win_uac_bypass_cmstp.yml
Raw Tags
attack.privilege-escalationattack.defense-evasionattack.t1548.002attack.t1218.003
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