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Description

The following detection identifies Microsoft Winword.exe spawning Windows Script Host - cscript.exe or wscript.exe. Typically, this is not common behavior and not default with Winword.exe. Winword.exe will generally be found in the following path C:\Program Files\Microsoft Office\root\Office16 (version will vary). cscript.exe or wscript.exe default location is c:\windows\system32\ or c:windows\syswow64`. cscript.exe or wscript.exe spawning from Winword.exe is common for a spearphishing attachment and is actively used. Albeit, the command-line executed will most likely be obfuscated and captured via another detection. During triage, review parallel processes and identify any files that may have been written. Review the reputation of the remote destination and block accordingly.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2021-04-12
  • Author: Michael Haag, Splunk
  • ID: 637e1b5c-9be1-11eb-9c32-acde48001122

ATT&CK

ID Technique Tactic
T1566.001 Spearphishing Attachment Initial Access

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name="winword.exe" Processes.process_name IN ("cscript.exe", "wscript.exe") by Processes.dest Processes.user 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)` 
| `winword_spawning_windows_script_host_filter`

Associated Analytic Story

How To Implement

To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the Endpoint datamodel in the Processes node.

Required field

  • _time
  • process_name
  • process_id
  • parent_process_name
  • dest
  • user
  • parent_process_id

Kill Chain Phase

  • Exploitation

Known False Positives

There will be limited false positives and it will be different for every environment. Tune by child process or command-line as needed.

RBA

Risk Score Impact Confidence Message
70.0 70 100 User $user$ on $dest$ spawned Windows Script Host from Winword.exe

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

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