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Description

The following analytic detects the use of the [Adsisearcher] type accelerator in PowerShell scripts to query Active Directory for domain computers. It leverages PowerShell Script Block Logging (EventCode=4104) to identify specific script blocks containing adsisearcher and objectcategory=computer with methods like findAll() or findOne(). This activity is significant as it may indicate an attempt by adversaries or Red Teams to perform Active Directory discovery and gain situational awareness. If confirmed malicious, this could lead to further reconnaissance and potential lateral movement within the network.

  • Type: TTP

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-05-09
  • Author: Mauricio Velazco, Splunk
  • ID: 70803451-0047-4e12-9d63-77fa7eb8649c

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1018 Remote System Discovery Discovery
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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`powershell` EventCode=4104 ScriptBlockText = "*adsisearcher*" AND ScriptBlockText = "*objectcategory=computer*" AND ScriptBlockText IN ("*findAll()*","*findOne()*") 
| stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText Computer UserID 
| rename Computer as dest 
|rename UserID as user 
| `security_content_ctime(firstTime)` 
| `remote_system_discovery_with_adsisearcher_filter`

Macros

The SPL above uses the following Macros:

:information_source: remote_system_discovery_with_adsisearcher_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • EventCode
  • ScriptBlockText
  • Computer
  • UserID

How To Implement

To successfully implement this analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup here https://docs.splunk.com/Documentation/UBA/5.0.4.1/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.

Known False Positives

Administrators or power users may use Adsisearcher for troubleshooting.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
15.0 30 50 Remote system discovery enumeration with adsisearcher on $dest$ by $user$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 3