Windows AD DCShadow Privileges ACL Addition

name: Windows AD DCShadow Privileges ACL Addition
id: ae915743-1aa8-4a94-975c-8062ebc8b723
version: 11
creation_date: '2024-07-01'
modification_date: '2026-05-13'
author: Dean Luxton
status: production
type: TTP
description: This detection identifies an Active Directory access-control list (ACL) modification event, which applies the minimum required extended rights to perform the DCShadow attack.
data_source:
    - Windows Event Log Security 5136
search: |-
    `wineventlog_security` EventCode=5136 ObjectClass=domainDNS
      | stats min(_time) as _time values(eval(if(OperationType=="%%14675",AttributeValue,null))) as old_value values(eval(if(OperationType=="%%14674",AttributeValue,null))) as new_value values(OperationType) as OperationType values(dest) as dest
        BY ObjectClass ObjectDN OpCorrelationID
           src_user SubjectLogonId
      | rex field=old_value max_match=10000 "\((?P<old_values>.*?)\)"
      | rex field=new_value max_match=10000 "\((?P<new_ace>.*?)\)"
      | mvexpand new_ace
      | where NOT new_ace IN (old_values)
      | rex field=new_ace "(?P<aceType>.*?);(?P<aceFlags>.*?);(?P<aceAccessRights>.*?);(?P<aceObjectGuid>.*?);;(?P<aceSid>.*?)$"
      | search aceObjectGuid IN ("9923a32a-3607-11d2-b9be-0000f87a36b2","1131f6ab-9c07-11d1-f79f-00c04fc2dcd2","1131f6ac-9c07-11d1-f79f-00c04fc2dcd2")
      | rex max_match=100 field=aceAccessRights "(?P<AccessRights>[A-Z]{2})"
      | rex max_match=100 field=aceFlags "(?P<aceFlags>[A-Z]{2})"
      | lookup msad_guid_lookup guid as aceObjectGuid OUTPUT displayName as ControlAccessRights
      | lookup ace_access_rights_lookup access_rights_string as AccessRights OUTPUT access_rights_value
      | lookup ace_type_lookup ace_type_string as aceType OUTPUT ace_type_value
      | lookup ace_flag_lookup flag_string as aceFlags OUTPUT flag_value as ace_flag_value ``` Optional SID resolution lookups
      | lookup identity_lookup_expanded objectSid as aceSid OUTPUT downLevelDomainName as user
      | lookup admon_groups_def objectSid as aceSid OUTPUT cn as group ```
      | lookup builtin_groups_lookup builtin_group_string  as aceSid OUTPUT builtin_group_name as builtin_group
      | eval aceType=coalesce(ace_type_value,aceType), aceFlags=coalesce(ace_flag_value,"This object only"), aceAccessRights=if(aceAccessRights="CCDCLCSWRPWPDTLOCRSDRCWDWO","Full control",coalesce(access_rights_value,AccessRights)), aceControlAccessRights=coalesce(ControlAccessRights,aceObjectGuid), user=coalesce(user, group, builtin_group, aceSid)
      | stats min(_time) as _time values(aceType) as aceType values(aceFlags) as aceFlags(inheritance) values(aceControlAccessRights) as aceControlAccessRights values(aceAccessRights) as aceAccessRights values(new_ace) as new_ace values(SubjectLogonId) as SubjectLogonId
        BY ObjectClass ObjectDN src_user
           user
      | search (aceControlAccessRights="Add/Remove Replica In Domain" AND aceControlAccessRights="Manage Replication Topology" AND aceControlAccessRights="Replication Synchronization") OR (aceControlAccessRights="9923a32a-3607-11d2-b9be-0000f87a36b2" AND aceControlAccessRights="1131f6ab-9c07-11d1-f79f-00c04fc2dcd2" AND aceControlAccessRights="1131f6ac-9c07-11d1-f79f-00c04fc2dcd2")
      | `windows_ad_dcshadow_privileges_acl_addition_filter`
how_to_implement: Ensure you are ingesting Active Directory audit logs - specifically event 5136. See lantern article in references for further on how to onboard AD audit data. Ensure the wineventlog_security macro is configured with the correct indexes and include lookups for SID resolution if evt_resolve_ad_obj is set to 0.
known_false_positives: No false positives have been identified at this time.
references:
    - https://www.labofapenetrationtester.com/2018/04/dcshadow.html
    - https://github.com/samratashok/nishang/blob/master/ActiveDirectory/Set-DCShadowPermissions.ps1
    - https://trustedsec.com/blog/a-hitchhackers-guide-to-dacl-based-detections-part-1-a
    - https://lantern.splunk.com/Security/Product_Tips/Enterprise_Security/Enabling_an_audit_trail_from_Active_Directory
finding:
    title: ACL modification Event Initiated by $src_user$ applying $user$ the minimum required extended rights to perform a DCShadow attack.
    entity:
        field: src_user
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: user
          type: user
          score: 50
          message: ACL modification Event Initiated by $src_user$ applying $user$ the minimum required extended rights to perform a DCShadow attack.
analytic_story:
    - Sneaky Active Directory Persistence Tricks
asset_type: Endpoint
mitre_attack_id:
    - T1484
    - T1207
    - T1222.001
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint