Name:Windows Linked Policies In ADSI Discovery id:510ea428-4731-4d2f-8829-a28293e427aa version:3 date:2024-09-30 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()*" | stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText Computer user_id | rename Computer as dest, user_id as user | `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 drilldown_searches: name:'View the detection results for - "$dest$"' search:'%original_detection_search% | search dest = "$dest$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$dest$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' tags: analytic_story: - 'Data Destruction' - 'Active Directory Discovery' - 'Industroyer2' asset_type:Endpoint confidence:50 impact:50 message:Windows PowerShell [Adsisearcher] was used user enumeration on $user$ mitre_attack_id: - 'T1087.002' - 'T1087' observable: name:'dest' type:'Endpoint' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'EventCode' - 'ScriptBlockText' - 'Computer' - 'user_id' risk_score:25 security_domain:endpoint
