Sigma rule: UAC Bypass Using NTFS Reparse Point - Process

Rule

Title

UAC Bypass Using NTFS Reparse Point - Process

Status

test

Level

high

Author

Christian Burkard (Nextron Systems)

Date

2021-08-30

Modified

2024-12-01

File

rules/windows/process_creation/proc_creation_win_uac_bypass_ntfs_reparse_point.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

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

Log source

product

windows

category

process_creation

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*

False positives (as the rule lists them)

• Unknown

Tags

• attack.privilege-escalation
• attack.t1548.002

MITRE ATT&CK ids this rule names

• T1548.002

References

• https://github.com/hfiref0x/UACME

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_uac_bypass_ntfs_reparse_point.yml