Detectionhightest

UAC Bypass Using NTFS Reparse Point - Process

Detects the pattern of UAC Bypass using NTFS reparse point and wusa.exe DLL hijacking (UACMe 36)

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Launch

Christian Burkard (Nextron Systems)Created Mon Aug 30Updated Sun Dec 0139ed3c80-e6a1-431b-9df3-911ac53d08a7windows

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:
    selection1:
        CommandLine|startswith: '"C:\Windows\system32\wusa.exe"  /quiet C:\Users\'
        CommandLine|endswith: '\AppData\Local\Temp\update.msu'
        IntegrityLevel:
            - 'High'
            - 'System'
            - 'S-1-16-16384' # System
            - 'S-1-16-12288' # High
    selection2:
        ParentCommandLine: '"C:\Windows\system32\dism.exe" /online /quiet /norestart /add-package /packagepath:"C:\Windows\system32\pe386" /ignorecheck'
        IntegrityLevel:
            - 'High'
            - 'System'
        CommandLine|contains|all:
            - 'C:\Users\'
            - '\AppData\Local\Temp\'
            - '\dismhost.exe {'
        Image|endswith: '\DismHost.exe'
    condition: 1 of selection*