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Description

The following analytic detects the loading of WMI modules by Microsoft scripting processes like wscript.exe or cscript.exe. It leverages Sysmon EventCode 7 to identify instances where these scripting engines load specific WMI-related DLLs. This activity is significant because it can indicate the presence of malware, such as the FIN7 implant, which uses JavaScript to execute WMI queries for gathering host information to send to a C2 server. If confirmed malicious, this behavior could allow attackers to collect sensitive system information and maintain persistence within the environment.

  • Type: Anomaly

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

  • Last Updated: 2024-05-21
  • Author: Teoderick Contreras, Splunk
  • ID: 2eba3d36-14a6-11ec-a682-acde48001122

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1059 Command and Scripting Interpreter Execution
T1059.007 JavaScript Execution
Kill Chain Phase
  • Installation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


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`sysmon` EventCode =7 Image IN ("*\\wscript.exe", "*\\cscript.exe") ImageLoaded IN ("*\\fastprox.dll", "*\\wbemdisp.dll", "*\\wbemprox.dll", "*\\wbemsvc.dll" , "*\\wmiutils.dll", "*\\wbemcomn.dll") 
| stats min(_time) as firstTime max(_time) as lastTime count by Image EventCode process_name ProcessId ProcessGuid Computer ImageLoaded 
| rename Computer as dest 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `ms_scripting_process_loading_wmi_module_filter`

Macros

The SPL above uses the following Macros:

:information_source: ms_scripting_process_loading_wmi_module_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
  • Image
  • EventCode
  • process_name
  • ProcessId
  • ProcessGuid
  • dest
  • ImageLoaded

How To Implement

To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA. Tune and filter known instances where renamed rundll32.exe may be used.

Known False Positives

automation scripting language may used by network operator to do ldap query.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
9.0 30 30 $process_name$ loading wmi modules $ImageLoaded$ in $dest$

: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