UAC Bypass Using ChangePK and SLUI

Hunt Hypothesis

Detects an UAC bypass that uses changepk.exe and slui.exe (UACMe 61)

Detection Rule

Sigma (Original)

title: UAC Bypass Using ChangePK and SLUI
id: 503d581c-7df0-4bbe-b9be-5840c0ecc1fc
status: test
description: Detects an UAC bypass that uses changepk.exe and slui.exe (UACMe 61)
references:
    - https://mattharr0ey.medium.com/privilege-escalation-uac-bypass-in-changepk-c40b92818d1b
    - https://github.com/hfiref0x/UACME
    - https://medium.com/falconforce/falconfriday-detecting-uac-bypasses-0xff16-86c2a9107abf
author: Christian Burkard (Nextron Systems)
date: 2021-08-23
modified: 2024-12-01
tags:
    - attack.privilege-escalation
    - attack.t1548.002
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\changepk.exe'
        ParentImage|endswith: '\slui.exe'
        IntegrityLevel:
            - 'High'
            - 'System'
            - 'S-1-16-16384' # System
            - 'S-1-16-12288' # High
    condition: selection
falsepositives:
    - Unknown
level: high

KQL (Azure Sentinel)

imProcessCreate
| where TargetProcessName endswith "\\changepk.exe" and (ParentProcessName endswith "\\slui.exe" or ActingProcessName endswith "\\slui.exe") and (TargetProcessIntegrityLevel in~ ("High", "System", "S-1-16-16384", "S-1-16-12288"))

Required Data Sources

False Positive Guidance

• Unknown

MITRE ATT&CK Context

• Tactic: Privilege Escalation
• Technique: T1548.002 — T1548.002

References

• https://mattharr0ey.medium.com/privilege-escalation-uac-bypass-in-changepk-c40b92818d1b
• https://github.com/hfiref0x/UACME
• https://medium.com/falconforce/falconfriday-detecting-uac-bypasses-0xff16-86c2a9107abf
• SigmaHQ Rule