Detection: Recon Using WMI Class

Description

The following analytic detects suspicious PowerShell activity via EventCode 4104, where WMI performs event queries to gather information on running processes or services. This detection leverages PowerShell Script Block Logging to identify specific WMI queries targeting system information classes like Win32_Bios and Win32_OperatingSystem. This activity is significant as it often indicates reconnaissance efforts by an adversary to profile the compromised machine. If confirmed malicious, the attacker could gain detailed system information, aiding in further exploitation or lateral movement within the network.

Search

1`powershell` EventCode=4104 (ScriptBlockText= "*SELECT*" OR ScriptBlockText= "*Get-WmiObject*") AND (ScriptBlockText= "*Win32_Bios*" OR ScriptBlockText= "*Win32_OperatingSystem*" OR ScriptBlockText= "*Win32_Processor*" OR ScriptBlockText= "*Win32_ComputerSystem*" OR ScriptBlockText= "*Win32_PnPEntity*" OR ScriptBlockText= "*Win32_ShadowCopy*" OR ScriptBlockText= "*Win32_DiskDrive*" OR ScriptBlockText= "*Win32_PhysicalMemory*") 
2| stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText Computer UserID 
3| rename Computer as dest 
4| rename UserID as user
5| `security_content_ctime(firstTime)` 
6| `security_content_ctime(lastTime)` 
7| `recon_using_wmi_class_filter`

Data Source

Name	Platform	Sourcetype	Source
Powershell Script Block Logging 4104	Windows	'xmlwineventlog'	'XmlWinEventLog:Microsoft-Windows-PowerShell/Operational'

Macros Used

Annotations

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Implementation

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

network administrator may used this command for checking purposes

Associated Analytic Story

• AsyncRAT

• Data Destruction

• Hermetic Wiper

• Industroyer2

• LockBit Ransomware

• Malicious PowerShell

• MoonPeak

• Qakbot

Risk Based Analytics (RBA)

References

• https://news.sophos.com/en-us/2020/05/12/maze-ransomware-1-year-counting/

• https://docs.splunk.com/Documentation/UBA/5.0.4.1/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.

• https://blog.palantir.com/tampering-with-windows-event-tracing-background-offense-and-defense-4be7ac62ac63

• https://static1.squarespace.com/static/552092d5e4b0661088167e5c/t/59c1814829f18782e24f1fe2/1505853768977/Windows+PowerShell+Logging+Cheat+Sheet+ver+Sept+2017+v2.1.pdf

• https://www.crowdstrike.com/blog/investigating-powershell-command-and-script-logging/

• https://www.splunk.com/en_us/blog/security/hunting-for-malicious-powershell-using-script-block-logging.html

• https://www.welivesecurity.com/2022/04/12/industroyer2-industroyer-reloaded/

• https://blogs.vmware.com/security/2022/10/lockbit-3-0-also-known-as-lockbit-black.html

Detection Testing

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: GitHub | Version: 4