splunk-security_content/docs/_posts/2021-04-12-excel_spawning_windows_script_host.md

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title	excerpt	categories	last_modified_at	toc	tags
Excel Spawning Windows Script Host	Security Account Manager	Endpoint	2021-04-12	true	TTP T1003.002 Security Account Manager Credential Access Splunk Enterprise Splunk Enterprise Security Splunk Cloud Endpoint Exploitation

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Description

The following detection identifies Microsoft Excel spawning Windows Script Host - cscript.exe or wscript.exe. Typically, this is not common behavior and not default with Excel.exe. Excel.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.exeorwscript.exe` spawning from Excel.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: 57fe880a-9be3-11eb-9bf3-acde48001122

ATT&CK

ID	Technique	Tactic
T1003.002	Security Account Manager	Credential Access

Search

| tstats `security_content_summariesonly` count values(Processes.process) min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name="excel.exe" Processes.process_name IN ("cscript.exe", "wscript.exe")  by Processes.parent_process Processes.process_name Processes.user Processes.dest 
| `drop_dm_object_name("Processes")` 
| `security_content_ctime(firstTime)`
|`security_content_ctime(lastTime)` 
| `excel_spawning_windows_script_host_filter`

Associated Analytic Story

• Spearphishing Attachments

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

False positives should be limited, but if any are present, filter as needed. In some instances, cscript.exe is used for legitimate business practices.

RBA

Risk Score	Impact	Confidence	Message
80.0	80	100	An instance of parent_process_name spawning process_name was identified on endpoint dest by user user, indicating potential suspicious macro execution.

Reference

• https://app.any.run/tasks/8ecfbc29-03d0-421c-a5bf-3905d29192a2/
• https://attack.mitre.org/techniques/T1566/001/

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

• https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1566.001/macro/windows-sysmon.log

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