splunk-security_content/docs/_posts/2021-08-23-getlocaluser_with_powershell_script_block.md

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title	excerpt	categories	last_modified_at	toc	toc_label	tags
GetLocalUser with PowerShell Script Block	Account Discovery , Local Account	Endpoint	2021-08-23	true		Account Discovery Local Account Discovery Discovery Splunk Enterprise Splunk Enterprise Security Splunk Cloud

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Description

The following analytic utilizes PowerShell Script Block Logging (EventCode=4104) to identify the execution of the Get-LocalUser commandlet. The Get-LocalUser commandlet is used to return a list of all local users. Red Teams and adversaries may leverage this commandlet to enumerate users for situational awareness and Active Directory Discovery.

• Type: Hunting

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

• Last Updated: 2021-08-23

• Author: Mauricio Velazco, Splunk

• ID: 2e891cbe-0426-11ec-9c9c-acde48001122

Annotations

ATT&CK

ID	Technique	Tactic
T1087	Account Discovery	Discovery

| T1087.001 | Local Account | Discovery |

Kill Chain Phase

• Reconnaissance

NIST

CIS20

CVE

Search

`powershell` EventCode=4104 (Message = "*Get-LocalUser*") 
| stats count min(_time) as firstTime max(_time) as lastTime by EventCode Message ComputerName User 
| `security_content_ctime(firstTime)` 
| `getlocaluser_with_powershell_script_block_filter`

Macros

The SPL above uses the following Macros:

• powershell
• security_content_ctime

Note that getlocaluser_with_powershell_script_block_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required field

• _time

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 this PowerShell commandlet for troubleshooting.

Associated Analytic story

• Active Directory Discovery

RBA

Risk Score	Impact	Confidence	Message
15.0	30	50	Local user discovery enumeration using PowerShell on dest by user

Reference

• https://attack.mitre.org/techniques/T1087/001/

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

• https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1087.001/AD_discovery/windows-powershell.log

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