title: CMSTP UAC Bypass via COM Object Access
author: Nik Seetharaman, Christian Burkard
date: 2021/08/31
description: Detects UAC Bypass Attempt Using Microsoft Connection Manager Profile
    Installer Autoelevate-capable COM Objects (e.g. UACMe ID of 41, 43, 58 or 65)
detection:
    SELECTION_1:
        EventID: 1
    SELECTION_2:
        ParentImage: '*\DllHost.exe'
    SELECTION_3:
        IntegrityLevel: High
    SELECTION_4:
        IntegrityLevel: System
    SELECTION_5:
        ParentCommandLine: '* /Processid:{3E5FC7F9-9A51-4367-9063-A120244FBEC7}*'
    SELECTION_6:
        ParentCommandLine: '* /Processid:{3E000D72-A845-4CD9-BD83-80C07C3B881F}*'
    SELECTION_7:
        ParentCommandLine: '* /Processid:{BD54C901-076B-434E-B6C7-17C531F4AB41}*'
    SELECTION_8:
        ParentCommandLine: '* /Processid:{D2E7041B-2927-42FB-8E9F-7CE93B6DC937}*'
    SELECTION_9:
        ParentCommandLine: '* /Processid:{E9495B87-D950-4AB5-87A5-FF6D70BF3E90}*'
    condition: (SELECTION_1 and SELECTION_2 and (SELECTION_3 or SELECTION_4) and (SELECTION_5
        or SELECTION_6 or SELECTION_7 or SELECTION_8 or SELECTION_9))
falsepositives:
- Legitimate CMSTP use (unlikely in modern enterprise environments)
fields:
- CommandLine
- ParentCommandLine
- Hashes
id: 4b60e6f2-bf39-47b4-b4ea-398e33cfe253
level: high
logsource:
    category: process_creation
    product: windows
modified: 2019/07/31
references:
- https://web.archive.org/web/20190720093911/http://www.endurant.io/cmstp/detecting-cmstp-enabled-code-execution-and-uac-bypass-with-sysmon/
- https://twitter.com/hFireF0X/status/897640081053364225
- https://medium.com/falconforce/falconfriday-detecting-uac-bypasses-0xff16-86c2a9107abf
- https://github.com/hfiref0x/UACME
status: stable
tags:
- attack.execution
- attack.defense_evasion
- attack.privilege_escalation
- attack.t1548.002
- attack.t1088
- attack.t1218.003
- attack.t1191
- attack.g0069
- car.2019-04-001
yml_filename: win_cmstp_com_object_access.yml
yml_path: /Users/user/Documents/YamatoSecurity/sigma/rules/windows/process_creation