AdsiSearcher Account Discovery

 Original Source: [splunk source]
Name:AdsiSearcher Account Discovery
id:de7fcadc-04f3-11ec-a241-acde48001122
version:13
date:None
author:Teoderick Contreras, Mauricio Velazco, Splunk
status:production
type:TTP
Description:The following analytic detects the use of the `[Adsisearcher]` type accelerator in PowerShell to query Active Directory for domain users. It leverages PowerShell Script Block Logging (EventCode=4104) to identify script blocks containing `[adsisearcher]`, `objectcategory=user`, and `.findAll()`. This activity is significant as it may indicate an attempt by adversaries or Red Teams to enumerate domain users for situational awareness and Active Directory discovery. If confirmed malicious, this could lead to further reconnaissance, privilege escalation, or lateral movement within the network.
Data_source:
  • -Powershell Script Block Logging 4104
search:`powershell` EventCode=4104 ScriptBlockText = "*[adsisearcher]*" ScriptBlockText = "*objectcategory=user*" 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)`

| `adsisearcher_account_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://attack.mitre.org/techniques/T1087/002/
  -https://www.blackhillsinfosec.com/red-blue-purple/
  -https://devblogs.microsoft.com/scripting/use-the-powershell-adsisearcher-type-accelerator-to-search-active-directory/
drilldown_searches:
 name:'View the detection results for - "$dest$" and "$user_id$"'
 search:'%original_detection_search% | search dest = "$dest$" user_id = "$user_id$"'
 earliest_offset:'$info_min_time$'
 latest_offset:'$info_max_time$'
 name:'View risk events for the last 7 days for - "$dest$" and "$user_id$"'
 search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$", "$user_id$") | 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:'7d'
 latest_offset:'0'
analytic_story:['Industroyer2', 'Active Directory Discovery', 'CISA AA23-347A', 'Data Destruction', 'Scattered Lapsus$ Hunters']

asset_type:Endpoint

mitre_attack_id:['T1087.002']

product:['Splunk Enterprise', 'Splunk Enterprise Security', 'Splunk Cloud']

category:endpoint

security_domain:endpoint

tags:

tests:
 name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1087.002/AD_discovery/adsisearcher_powershell.log
  source: XmlWinEventLog:Microsoft-Windows-PowerShell/Operational
  sourcetype: XmlWinEventLog
 test_type:'unit'
manual_test:None