UAC Bypass Using Windows Media Player - Registry

Hunt Hypothesis

Detects the pattern of UAC Bypass using Windows Media Player osksupport.dll (UACMe 32)

Detection Rule

Sigma (Original)

title: UAC Bypass Using Windows Media Player - Registry
id: 5f9db380-ea57-4d1e-beab-8a2d33397e93
status: test
description: Detects the pattern of UAC Bypass using Windows Media Player osksupport.dll (UACMe 32)
references:
    - https://github.com/hfiref0x/UACME
author: Christian Burkard (Nextron Systems)
date: 2021-08-23
modified: 2023-08-17
tags:
    - attack.privilege-escalation
    - attack.t1548.002
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|endswith: '\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Compatibility Assistant\Store\C:\Program Files\Windows Media Player\osk.exe'
        Details: 'Binary Data'
    condition: selection
falsepositives:
    - Unknown
level: high

KQL (Azure Sentinel)

imRegistry
| where RegistryKey endswith "\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\AppCompatFlags\\Compatibility Assistant\\Store\\C:\\Program Files\\Windows Media Player\\osk.exe" and RegistryValueData =~ "Binary Data"

KQL (Microsoft 365 Defender)

DeviceRegistryEvents
| where RegistryKey endswith "\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\AppCompatFlags\\Compatibility Assistant\\Store\\C:\\Program Files\\Windows Media Player\\osk.exe" and RegistryValueData =~ "Binary Data"

Required Data Sources

False Positive Guidance

• Unknown

MITRE ATT&CK Context

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

References

• https://github.com/hfiref0x/UACME
• SigmaHQ Rule