Try in Splunk Security Cloud

Description

This analytic is to detect a suspicious spawned process by wscript or cscript process. This technique was a common technique used by adversaries and malware to execute different LOLBIN, other script like powershell or create a suspended process to inject its code as a defense evasion. This TTP may detect some normal script that using several application tool that are in the list of the child process it detects but a good pivot and indicator that a script is may execute suspicious code.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2021-10-06
  • Author: Teoderick Contreras, Splunk
  • ID: 1f35e1da-267b-11ec-90a9-acde48001122

ATT&CK

ID Technique Tactic
T1055 Process Injection Defense Evasion, Privilege Escalation
T1543 Create or Modify System Process Persistence, Privilege Escalation
T1134.004 Parent PID Spoofing Defense Evasion, Privilege Escalation
T1134 Access Token Manipulation Defense Evasion, Privilege Escalation

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name IN ("cscript.exe", "wscript.exe") Processes.process_name IN ("regsvr32.exe", "rundll32.exe","winhlp32.exe","certutil.exe","msbuild.exe","cmd.exe","powershell*","wmic.exe","mshta.exe") by Processes.dest Processes.user Processes.parent_process_name Processes.parent_process Processes.process_name Processes.process Processes.process_id Processes.parent_process_id 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `wscript_or_cscript_suspicious_child_process_filter`

Associated Analytic Story

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.

Required field

  • _time
  • Processes.dest
  • Processes.user
  • Processes.parent_process_name
  • Processes.parent_process
  • Processes.original_file_name
  • Processes.process_name
  • Processes.process
  • Processes.process_id
  • Processes.parent_process_path
  • Processes.process_path
  • Processes.parent_process_id

Kill Chain Phase

  • Exploitation

Known False Positives

user may create vbs or js script that use several tool as part of its execution.

RBA

Risk Score Impact Confidence Message
49.0 70 70 wscript or cscript parent process spawned $process_name$ in $dest$

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: 1