PowerShell Invoke WmiExec Usage

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Description

The following analytic detects the usage of the Invoke-WMIExec utility within PowerShell Script Block Logging (EventCode 4104). The utility is used for executing WMI commands on targets using NTLMv2 pass-the-hash authentication.

• Type: TTP

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

• Last Updated: 2023-03-22
• Author: Michael Haag, Splunk
• ID: 0734bd21-2769-4972-a5f1-78bb1e011224

Annotations

ATT&CK

ATT&CK

ID	Technique	Tactic
T1047	Windows Management Instrumentation	Execution

Kill Chain Phase

• Installation

NIST

• DE.CM

CIS20

• CIS 10

CVE

Search

`powershell` EventCode=4104 ScriptBlockText IN ("*invoke-wmiexec*") 
| stats count min(_time) as firstTime max(_time) as lastTime by Computer EventCode ScriptBlockText 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `powershell_invoke_wmiexec_usage_filter`

Macros

The SPL above uses the following Macros:

• powershell
• security_content_ctime

powershell_invoke_wmiexec_usage_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

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

False positives should be limited as this analytic is designed to detect a specific utility. It is recommended to apply appropriate filters as needed to minimize the number of false positives.

Associated Analytic Story

• Suspicious WMI Use

RBA

Risk Score	Impact	Confidence	Message
100.0	100	100	PowerShell was identified running a Invoke-WmiExec on $Computer$.

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

• https://github.com/Kevin-Robertson/Invoke-TheHash/blob/master/Invoke-WMIExec.ps1

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

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