Windows.Registry.HiddenUsers

Find hidden user accounts through registry values on the filesystem.

In Windows, adversaries may hide user accounts via settings in the Registry. For example, an adversary may add a value to the Windows Registry (via Reg or other means) that will hide the user “test” from the Windows login screen:

reg.exe ADD ‘HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\SpecialAccounts\UserList’ /v test /t REG_DWORD /d 0 /f.

• ATT&CK tactic: Defense Evasion, Hide Artifacts: Hidden Users
• ATT&CK technique: T1564.002

name: Windows.Registry.HiddenUsers
description: |
    Find hidden user accounts through registry values on the filesystem.

    In Windows, adversaries may hide user accounts via settings in the Registry. 
    For example, an adversary may add a value to the Windows Registry 
    (via Reg or other means) that will hide the user "test" from 
    the Windows login screen: 
    
    reg.exe ADD 'HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\SpecialAccounts\UserList' /v test /t REG_DWORD /d 0 /f.

    * ATT&CK tactic: Defense Evasion, Hide Artifacts: Hidden Users
    * ATT&CK technique: T1564.002

reference:
  - https://attack.mitre.org/techniques/T1564/002/
  - https://github.com/Res260/conti_202202_leak_procedures/blob/main/12_using_anydesk.txt
  
type: CLIENT

author: Eduardo Mattos - @eduardfir

precondition:
  SELECT * FROM info() where OS = 'windows'

parameters:
  - name: SearchRegistryGlob
    default: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\SpecialAccounts\Userlist\**
    description: Use a glob to define the keys that will be searched.

sources:
  - query: |
        SELECT  Name,
                FullPath,
                Data,
                Sys,
                ModTime as Modified
        FROM glob(globs=SearchRegistryGlob, accessor='registry')

column_types:
  - name: Modified
    type: timestamp