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Windows AD DCShadow Privileges ACL Addition

This detection identifies an Active Directory access-control list (ACL) modification event, which applies the minimum required extended rights to perform the DCShadow attack.

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Rule sourcedetections/endpoint/windows_ad_dcshadow_privileges_acl_addition.yml
`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`