name: Excel Spawning Windows Script Host
id: 57fe880a-9be3-11eb-9bf3-acde48001122
version: 1
date: '2021-04-12'
author: Michael Haag, Splunk
status: production
type: TTP
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.
data_source:
- Sysmon Event ID 1
search:
  selection1:
    Image|endswith:
    - cscript.exe
    - wscript.exe
    ParentImage: excel.exe
  condition: selection1
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
  asset_type: Endpoint
  confidence: 100
  impact: 80
  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
  - T1003
  observable:
  - name: user
    type: User
    role:
    - Victim
  - name: dest
    type: Hostname
    role:
    - Victim
  - name: parent_process_name
    type: Process
    role:
    - Parent Process
  - name: process_name
    type: Process
    role:
    - Child Process
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  risk_score: 80
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1566.001/macro/windows-sysmon.log
    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
    sourcetype: xmlwineventlog