name: Excel Spawning Windows Script Host
id: 57fe880a-9be3-11eb-9bf3-acde48001122
version: 1
date: '2021-04-12'
author: Michael Haag, Splunk
type: TTP
datamodel:
- Endpoint
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.exe` or `wscript.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.
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`'
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.
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.
references:
- https://app.any.run/tasks/8ecfbc29-03d0-421c-a5bf-3905d29192a2/
- https://attack.mitre.org/techniques/T1566/001/
tags:
  analytic_story:
  - Spearphishing Attachments
  automated_detection_testing: passed
  confidence: 100
  context:
  - Source:Endpoint
  - Stage:Execution
  dataset:
  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1566.001/macro/windows-sysmon.log
  impact: 80
  kill_chain_phases:
  - Exploitation
  message: An instance of $parent_process_name$ spawning $process_name$ was identified
    on endpoint $dest$ by user $user$, indicating potential suspicious macro execution.
  mitre_attack_id:
  - T1003.002
  observable:
  - name: user
    type: User
    role:
    - Victim
  - name: dest
    type: Hostname
    role:
    - Victim
  - name: parent_process_name
    type: Parent Process
    role:
    - Parent Process
  - name: process_name
    type: Process
    role:
    - Child Process
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - process_name
  - process_id
  - parent_process_name
  - dest
  - user
  - parent_process_id
  risk_score: 80
  security_domain: endpoint