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Description

The following analytic detects the execution of suspicious PowerShell commands associated with Meterpreter modules, such as "MSF.Powershell" and "MSF.Powershell.Meterpreter". It leverages PowerShell Script Block Logging (EventCode=4104) to capture and analyze the full command sent to PowerShell. This activity is significant as it indicates potential post-exploitation actions, including credential dumping and persistence mechanisms. If confirmed malicious, an attacker could gain extensive control over the compromised system, escalate privileges, and maintain long-term access, posing a severe threat to the environment.

  • Type: TTP

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

  • Last Updated: 2024-05-19
  • Author: Michael Haag, Splunk
  • ID: d5905da5-d050-48db-9259-018d8f034fcf

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1059 Command and Scripting Interpreter Execution
T1059.001 PowerShell Execution
Kill Chain Phase
  • Installation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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`powershell` EventCode=4104 ScriptBlockText IN ("*MSF.Powershell*","*MSF.Powershell.Meterpreter*","*MSF.Powershell.Meterpreter.Kiwi*","*MSF.Powershell.Meterpreter.Transport*") 
| stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText Computer user_id 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `powershell_load_module_in_meterpreter_filter`

Macros

The SPL above uses the following Macros:

:information_source: powershell_load_module_in_meterpreter_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
  • User_id

How To Implement

The following 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

False positives should be very limited as this is strict to MetaSploit behavior.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
100.0 100 100 PowerShell was identified running a script utilized by Meterpreter from MetaSploit on endpoint $Computer$ by user $user_id$.

: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: 2