Shell Open Registry Keys Manipulation

title: Shell Open Registry Keys Manipulation
id: 152f3630-77c1-4284-bcc0-4cc68ab2f6e7
related:
    - id: dd3ee8cc-f751-41c9-ba53-5a32ed47e563
      type: similar
status: test
description: |
    Detects manipulation of shell open command registry keys such as "ms-settings" and "exefile",
    which are commonly abused to achieve UAC bypass (e.g. via fodhelper.exe) or establish persistence
    through file association hijacking.
references:
    - https://github.com/hfiref0x/UACME
    - https://winscripting.blog/2017/05/12/first-entry-welcome-and-uac-bypass/
    - https://github.com/RhinoSecurityLabs/Aggressor-Scripts/tree/master/UACBypass
    - https://tria.ge/211119-gs7rtshcfr/behavioral2 [Lokibot sample from Nov 2021]
author: Christian Burkard (Nextron Systems)
date: 2021-08-30
modified: 2026-08-27
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.t1548.002
    - attack.t1546.001
logsource:
    category: registry_event
    product: windows
detection:
    selection_1:
        EventType: SetValue
        TargetObject|endswith: 'Classes\ms-settings\shell\open\command\SymbolicLinkValue'
        Details|contains: '\Software\Classes\{'
    selection_2:
        TargetObject|endswith: 'Classes\ms-settings\shell\open\command\DelegateExecute'
    selection_3:
        EventType: SetValue
        TargetObject|endswith:
            - 'Classes\ms-settings\shell\open\command\(Default)'
            - 'Classes\exefile\shell\open\command\(Default)'
    filter_main_empty:
        Details: '(Empty)'
    filter_main_default_com:
        Details:
            - '{4813071a-41ad-44a2-9835-886d2f63ca30}'
            - '{A56A841F-E974-45C1-8001-7E3F8A085917}'
            - '{4ED3A719-CEA8-4BD9-910D-E252F997AFC2}'
            - '{BFEC0C93-0B7D-4F2C-B09C-AFFFC4BDAE78}'
    condition: 1 of selection_* and not 1 of filter_main_*
falsepositives:
    - Unknown
level: high