CMSTP UAC Bypass via COM Object Access

calendar Aug 12, 2024 · attack.execution attack.defense-evasion attack.privilege-escalation attack.t1548.002 attack.t1218.003 attack.g0069 car.2019-04-001  ·
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Detects UAC Bypass Attempt Using Microsoft Connection Manager Profile Installer Autoelevate-capable COM Objects (e.g. UACMe ID of 41, 43, 58 or 65)

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 1title: CMSTP UAC Bypass via COM Object Access
 2id: 4b60e6f2-bf39-47b4-b4ea-398e33cfe253
 3status: stable
 4description: Detects UAC Bypass Attempt Using Microsoft Connection Manager Profile Installer Autoelevate-capable COM Objects (e.g. UACMe ID of 41, 43, 58 or 65)
 5references:
 6    - https://web.archive.org/web/20190720093911/http://www.endurant.io/cmstp/detecting-cmstp-enabled-code-execution-and-uac-bypass-with-sysmon/
 7    - https://twitter.com/hFireF0X/status/897640081053364225
 8    - https://medium.com/falconforce/falconfriday-detecting-uac-bypasses-0xff16-86c2a9107abf
 9    - https://github.com/hfiref0x/UACME
10author: Nik Seetharaman, Christian Burkard (Nextron Systems)
11date: 2019-07-31
12modified: 2022-09-21
13tags:
14    - attack.execution
15    - attack.defense-evasion
16    - attack.privilege-escalation
17    - attack.t1548.002
18    - attack.t1218.003
19    - attack.g0069
20    - car.2019-04-001
21logsource:
22    category: process_creation
23    product: windows
24detection:
25    selection:
26        ParentImage|endswith: '\DllHost.exe'
27        ParentCommandLine|contains:
28            - ' /Processid:{3E5FC7F9-9A51-4367-9063-A120244FBEC7}' # cmstplua.dll
29            - ' /Processid:{3E000D72-A845-4CD9-BD83-80C07C3B881F}' # CMLUAUTIL
30            - ' /Processid:{BD54C901-076B-434E-B6C7-17C531F4AB41}' # EditionUpgradeManagerObj.dll
31            - ' /Processid:{D2E7041B-2927-42FB-8E9F-7CE93B6DC937}' # colorui.dll
32            - ' /Processid:{E9495B87-D950-4AB5-87A5-FF6D70BF3E90}' # wscui.cpl
33        IntegrityLevel:
34            - 'High'
35            - 'System'
36    condition: selection
37falsepositives:
38    - Legitimate CMSTP use (unlikely in modern enterprise environments)
39level: high

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