title: AD Object WriteDAC Access
id: 028c7842-4243-41cd-be6f-12f3cf1a26c7
status: test
description: Detects WRITE_DAC access to a domain object
references:
    - https://threathunterplaybook.com/hunts/windows/180815-ADObjectAccessReplication/notebook.html
    - https://threathunterplaybook.com/library/windows/active_directory_replication.html
    - https://threathunterplaybook.com/hunts/windows/190101-ADModDirectoryReplication/notebook.html
author: Roberto Rodriguez @Cyb3rWard0g
date: 2019-09-12
modified: 2021-11-27
tags:
    - attack.defense-impairment
    - attack.t1222.001
logsource:
    product: windows
    service: security
detection:
    selection:
        EventID: 4662
        ObjectServer: 'DS'
        AccessMask: '0x40000'
        ObjectType:
            - '19195a5b-6da0-11d0-afd3-00c04fd930c9'
            - 'domainDNS'
    condition: selection
falsepositives:
    - Unknown
level: critical

title: PowerShell Set-Acl On Windows Folder - PsScript
id: 3bf1d859-3a7e-44cb-8809-a99e066d3478
related:
    - id: cae80281-ef23-44c5-873b-fd48d2666f49 # PsScript Low
      type: derived
    - id: 0944e002-e3f6-4eb5-bf69-3a3067b53d73 # ProcCreation Susp
      type: derived
    - id: bdeb2cff-af74-4094-8426-724dc937f20a # ProcCreation Low
      type: derived
status: test
description: Detects PowerShell scripts to set the ACL to a file in the Windows folder
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/74438b0237d141ee9c99747976447dc884cb1a39/atomics/T1505.005/T1505.005.md
    - https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.security/set-acl?view=powershell-5.1
author: frack113, Nasreddine Bencherchali (Nextron Systems)
date: 2023-07-18
tags:
    - attack.defense-impairment
    - attack.t1222
logsource:
    product: windows
    category: ps_script
    definition: bade5735-5ab0-4aa7-a642-a11be0e40872
detection:
    selection_cmdlet:
        ScriptBlockText|contains|all:
            - 'Set-Acl '
            - '-AclObject '
    selection_paths:
        # Note: Add more suspicious paths
        ScriptBlockText|contains:
            - '-Path "C:\Windows'
            - '-Path "C:/Windows'
            - "-Path 'C:\\Windows"
            - "-Path 'C:/Windows"
            - '-Path C:\\Windows'
            - '-Path C:/Windows'
            - '-Path $env:windir'
            - '-Path "$env:windir'
            - "-Path '$env:windir"
    selection_permissions:
        # Note: Add more suspicious permissions
        ScriptBlockText|contains:
            - 'FullControl'
            - 'Allow'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

title: Chmod Targeting Sensitive Directories
id: 6419afd1-3742-47a5-a7e6-b50386cd15f8
status: test
description: |
    Detects chmod targeting files in sensitive directory paths on Linux systems.
    Attackers may use chmod to change permissions of files in these directories to maintain persistence, escalate privileges, or disrupt system operations.
references:
    - https://www.intezer.com/blog/malware-analysis/new-backdoor-sysjoker/
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1222.002/T1222.002.md
author: 'Christopher Peacock @SecurePeacock, SCYTHE @scythe_io'
date: 2022-06-03
modified: 2026-03-18
tags:
    - attack.defense-impairment
    - attack.t1222.002
logsource:
    product: linux
    category: process_creation
detection:
    selection:
        Image|endswith: '/chmod'
        CommandLine|contains:
            - '/tmp/'
            - '/.Library/'
            - '/etc/'
            - '/opt/'
    filter_main_update_shells:
        CommandLine|contains: 'chmod --reference=/etc/shells'
        ParentCommandLine|endswith: '/update-shells'
    filter_main_postinst:
        CommandLine|contains: '/etc/'
        ParentCommandLine|contains|all:
            - '/var/lib/dpkg/info/'
            - '.postinst configure'
    filter_main_apt_key:
        CommandLine|startswith: 'chmod 700 /tmp/apt-key-gpghome.'
    filter_main_mkinitramfs:
        CommandLine|startswith: 'chmod 755 /var/tmp/mkinitramfs'
    filter_main_landscape:
        CommandLine: 'chmod 0775 /etc/landscape/'
    filter_main_ubuntu_apparmor:
        CommandLine: 'chmod 644 /etc/apparmor.d/tunables/home.d/ubuntu'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Some false positives are to be expected. Apply additional filters as needed before pushing to production.
level: medium

title: Potentially Suspicious NTFS Symlink Behavior Modification
id: c0b2768a-dd06-4671-8339-b16ca8d1f27f
status: test
description: |
    Detects the modification of NTFS symbolic link behavior using fsutil, which could be used to enable remote to local or remote to remote symlinks for potential attacks.
references:
    - https://www.cybereason.com/blog/cybereason-vs.-blackcat-ransomware
    - https://learn.microsoft.com/fr-fr/windows-server/administration/windows-commands/fsutil-behavior
    - https://thedfirreport.com/2025/06/30/hide-your-rdp-password-spray-leads-to-ransomhub-deployment/
author: frack113, The DFIR Report
date: 2022-03-02
modified: 2025-11-13
tags:
    - attack.execution
    - attack.defense-impairment
    - attack.t1059
    - attack.t1222.001
logsource:
    category: process_creation
    product: windows
detection:
    selection_img_proxy:
        # Note: Example command observed:  cmd.exe /c "fsutil behaviour set SymlinkEvaluation"
        - Image|endswith:
              - '\cmd.exe'
              - '\powershell.exe'
              - '\pwsh.exe'
        - OriginalFileName:
              - 'Cmd.Exe'
              - 'PowerShell.EXE'
              - 'pwsh.dll'
    selection_fsutil_cli:
        CommandLine|contains|all:
            - 'fsutil'
            - 'behavior'
            - 'set'
            - 'SymlinkEvaluation'
    selection_symlink_params:
        CommandLine|contains:
            - 'R2L:1' # Remote to Local
            - 'R2R:1' # Remote to Remote
            - 'L2L:1' # Local to Local
    condition: all of selection_*
falsepositives:
    - Legitimate usage, investigate the parent process and context to determine if benign.
level: medium

title: Remove Immutable File Attribute
id: 34979410-e4b5-4e5d-8cfb-389fdff05c12
related:
    - id: a5b977d6-8a81-4475-91b9-49dbfcd941f7
      type: derived
status: test
description: Detects usage of the 'chattr' utility to remove immutable file attribute.
references:
    - https://www.trendmicro.com/en_us/research/22/i/how-malicious-actors-abuse-native-linux-tools-in-their-attacks.html
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-09-15
tags:
    - attack.defense-impairment
    - attack.t1222.002
logsource:
    product: linux
    category: process_creation
detection:
    selection:
        Image|endswith: '/chattr'
        CommandLine|contains: ' -i '
    condition: selection
falsepositives:
    - Administrator interacting with immutable files (e.g. for instance backups).
level: medium

title: Remove Immutable File Attribute - Auditd
id: a5b977d6-8a81-4475-91b9-49dbfcd941f7
status: test
description: Detects removing immutable file attribute.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1222.002/T1222.002.md
author: Jakob Weinzettl, oscd.community
date: 2019-09-23
modified: 2022-11-26
tags:
    - attack.defense-impairment
    - attack.t1222.002
logsource:
    product: linux
    service: auditd
detection:
    selection:
        type: 'EXECVE'
        a0|contains: 'chattr'
        a1|contains: '-i'
    condition: selection
falsepositives:
    - Administrator interacting with immutable files (e.g. for instance backups).
level: medium
simulation:
    - type: atomic-red-team
      name: Remove immutable file attribute
      technique: T1222.002
      atomic_guid: e7469fe2-ad41-4382-8965-99b94dd3c13f

title: Suspicious Recursive Takeown
id: 554601fb-9b71-4bcc-abf4-21a611be4fde
status: test
description: Adversaries can interact with the DACLs using built-in Windows commands takeown which can grant adversaries higher permissions on specific files and folders
references:
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/takeown
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1222.001/T1222.001.md#atomic-test-1---take-ownership-using-takeown-utility
author: frack113
date: 2022-01-30
modified: 2022-11-21
tags:
    - attack.defense-impairment
    - attack.t1222.001
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\takeown.exe'
        CommandLine|contains|all:
            - '/f '
            - '/r'
    condition: selection
falsepositives:
    - Scripts created by developers and admins
    - Administrative activity
level: medium

title: File or Folder Permissions Change
id: 74c01ace-0152-4094-8ae2-6fd776dd43e5
status: test
description: Detects file and folder permission changes.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1222.002/T1222.002.md
author: Jakob Weinzettl, oscd.community
date: 2019-09-23
modified: 2021-11-27
tags:
    - attack.defense-impairment
    - attack.t1222.002
logsource:
    product: linux
    service: auditd
detection:
    selection:
        type: 'EXECVE'
        a0|contains:
            - 'chmod'
            - 'chown'
    condition: selection
falsepositives:
    - User interacting with files permissions (normal/daily behaviour).
level: low

title: PowerShell Script Change Permission Via Set-Acl - PsScript
id: cae80281-ef23-44c5-873b-fd48d2666f49
related:
    - id: 0944e002-e3f6-4eb5-bf69-3a3067b53d73 # ProcCreation Susp
      type: derived
    - id: bdeb2cff-af74-4094-8426-724dc937f20a # ProcCreation Low
      type: derived
    - id: 3bf1d859-3a7e-44cb-8809-a99e066d3478 # PsScript High
      type: derived
status: test
description: Detects PowerShell scripts set ACL to of a file or a folder
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/74438b0237d141ee9c99747976447dc884cb1a39/atomics/T1505.005/T1505.005.md
author: frack113, Nasreddine Bencherchali (Nextron Systems)
date: 2023-07-18
tags:
    - attack.defense-impairment
    - attack.t1222
logsource:
    product: windows
    category: ps_script
    definition: bade5735-5ab0-4aa7-a642-a11be0e40872
detection:
    selection:
        ScriptBlockText|contains|all:
            - 'Set-Acl '
            - '-AclObject '
            - '-Path '
    condition: selection
falsepositives:
    - Unknown
level: low