Windows Linked Policies In ADSI Discovery

name: Windows Linked Policies In ADSI Discovery
id: 510ea428-4731-4d2f-8829-a28293e427aa
version: 11
creation_date: '2021-08-25'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: The following analytic detects the use of the `[Adsisearcher]` type accelerator in PowerShell Script Block Logging (EventCode=4104) to query Active Directory for domain organizational units. This detection leverages PowerShell operational logs to identify script blocks containing `[adsisearcher]`, `objectcategory=organizationalunit`, and `findAll()`. This activity is significant as it indicates potential reconnaissance efforts by adversaries to gain situational awareness of the domain structure. If confirmed malicious, this could lead to further exploitation, such as privilege escalation or lateral movement within the network.
data_source:
    - Powershell Script Block Logging 4104
search: |-
    `powershell` EventCode=4104 ScriptBlockText = "*[adsisearcher]*" ScriptBlockText = "*objectcategory=organizationalunit*" ScriptBlockText = "*findAll()*"
      | fillnull
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY dest signature signature_id
           user_id vendor_product EventID
           Guid Opcode Name
           Path ProcessID ScriptBlockId
           ScriptBlockText
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `windows_linked_policies_in_adsi_discovery_filter`
how_to_implement: The following Hunting analytic requires PowerShell operational logs to be imported. Modify the powershell macro as needed to match the sourcetype or add index. This analytic is specific to 4104, or PowerShell Script Block Logging.
known_false_positives: Administrators or power users may use this command for troubleshooting.
references:
    - https://www.welivesecurity.com/2022/04/12/industroyer2-industroyer-reloaded/
    - https://medium.com/@pentesttas/discover-hidden-gpo-s-on-active-directory-using-ps-adsi-a284b6814c81
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: Windows PowerShell [Adsisearcher] was used user enumeration on $user_id$
analytic_story:
    - Data Destruction
    - Active Directory Discovery
    - Industroyer2
asset_type: Endpoint
mitre_attack_id:
    - T1087.002
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint