title: Hiding User Account Via SpecialAccounts Registry Key
id: f8aebc67-a56d-4ec9-9fbe-7b0e8b7b4efd
related:
    - id: 8a58209c-7ae6-4027-afb0-307a78e4589a
      type: obsolete
    - id: 9ec9fb1b-e059-4489-9642-f270c207923d
      type: similar
status: test
description: Detects modifications to the registry key "HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\SpecialAccounts\Userlist" where the value is set to "0" in order to hide user account from being listed on the logon screen.
references:
    - https://thedfirreport.com/2022/07/11/select-xmrig-from-sqlserver/
    - https://github.com/redcanaryco/atomic-red-team/blob/40b77d63808dd4f4eafb83949805636735a1fd15/atomics/T1564.002/T1564.002.md#atomic-test-3---create-hidden-user-in-registry
author: Nasreddine Bencherchali (Nextron Systems), frack113
date: 2022-07-12
modified: 2023-01-26
tags:
    - attack.stealth
    - attack.t1564.002
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains: '\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\SpecialAccounts\UserList'
        Details: 'DWORD (0x00000000)'
    condition: selection
falsepositives:
    - Unknown
level: high
regression_tests_path: regression_data/rules/windows/registry/registry_set/registry_set_special_accounts/info.yml
simulation:
    - type: atomic-red-team
      name: Create Hidden User in Registry
      technique: T1564.002
      atomic_guid: 173126b7-afe4-45eb-8680-fa9f6400431c

title: Hidden User Creation
id: b22a5b36-2431-493a-8be1-0bae56c28ef3
status: test
description: Detects creation of a hidden user account on macOS (UserID < 500) or with IsHidden option
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1564.002/T1564.002.md
author: Daniil Yugoslavskiy, oscd.community
date: 2020-10-10
modified: 2021-11-27
tags:
    - attack.stealth
    - attack.t1564.002
logsource:
    category: process_creation
    product: macos
detection:
    dscl_create:
        Image|endswith: '/dscl'
        CommandLine|contains: 'create'
    id_below_500:
        CommandLine|contains: UniqueID
        CommandLine|re: '([0-9]|[1-9][0-9]|[1-4][0-9]{2})'
    ishidden_option_declaration:
        CommandLine|contains: 'IsHidden'
    ishidden_option_confirmation:
        CommandLine|contains:
            - 'true'
            - 'yes'
            - '1'
    condition: dscl_create and id_below_500 or dscl_create and (ishidden_option_declaration and ishidden_option_confirmation)
falsepositives:
    - Legitimate administration activities
level: medium

title: Hiding User Account Via SpecialAccounts Registry Key - CommandLine
id: 9ec9fb1b-e059-4489-9642-f270c207923d
related:
    - id: f8aebc67-a56d-4ec9-9fbe-7b0e8b7b4efd
      type: similar
status: test
description: |
    Detects changes to the registry key "HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\SpecialAccounts\Userlist" where the value is set to "0" in order to hide user account from being listed on the logon screen.
references:
    - https://thedfirreport.com/2024/01/29/buzzing-on-christmas-eve-trigona-ransomware-in-3-hours/
    - https://thedfirreport.com/2024/04/01/from-onenote-to-ransomnote-an-ice-cold-intrusion/
    - https://thedfirreport.com/2024/04/29/from-icedid-to-dagon-locker-ransomware-in-29-days/
    - https://thedfirreport.com/2022/07/11/select-xmrig-from-sqlserver/
author: '@Kostastsale, TheDFIRReport'
date: 2022-05-14
modified: 2024-08-23
tags:
    - attack.stealth
    - attack.t1564.002
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\reg.exe'
        CommandLine|contains|all:
            - '\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\SpecialAccounts\UserList'
            - 'add'
            - '/v'
            - '/d 0'
    condition: selection
falsepositives:
    - System administrator activities
level: medium
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_registry_special_accounts_hide_user/info.yml

title: Potential Suspicious Activity Using SeCEdit
id: c2c76b77-32be-4d1f-82c9-7e544bdfe0eb
status: test
description: Detects potential suspicious behaviour using secedit.exe. Such as exporting or modifying the security policy
references:
    - https://blueteamops.medium.com/secedit-and-i-know-it-595056dee53d
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/secedit
author: Janantha Marasinghe
date: 2022-11-18
modified: 2022-12-30
tags:
    - attack.collection
    - attack.discovery
    - attack.persistence
    - attack.credential-access
    - attack.privilege-escalation
    - attack.execution
    - attack.stealth
    - attack.defense-impairment
    - attack.t1685.001
    - attack.t1547.001
    - attack.t1505.005
    - attack.t1556.002
    - attack.t1685
    - attack.t1574.007
    - attack.t1564.002
    - attack.t1546.008
    - attack.t1546.007
    - attack.t1547.014
    - attack.t1547.010
    - attack.t1547.002
    - attack.t1557
    - attack.t1082
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\secedit.exe'
        - OriginalFileName: 'SeCEdit'
    selection_flags_discovery:
        CommandLine|contains|all:
            - '/export'
            - '/cfg'
    selection_flags_configure:
        CommandLine|contains|all:
            - '/configure'
            - '/db'
    # filter:
    #     SubjectUserName|endswith: '$'  SubjectUserName is from event ID 4719 in the Windows Security log
    condition: selection_img and (1 of selection_flags_*)
falsepositives:
    - Legitimate administrative use
level: medium