name: Detect mshta renamed
id: 8f45fcf0-5b68-11eb-ae93-0242ac130002
version: 3
date: '2022-04-07'
author: Michael Haag, Splunk
status: production
type: Hunting
description: The following analytic identifies renamed instances of mshta.exe executing.
  Mshta.exe is natively found in C:\Windows\system32 and C:\Windows\syswow64. This
  analytic utilizes the internal name of the PE to identify if is the legitimate mshta
  binary. Further analysis should be performed to review the executed content and
  validation it is the real mshta.
data_source:
- Sysmon Event ID 1
search:
  selection1:
    OriginalFileName: MSHTA.EXE
    Image|endswith: mshta.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. In addition,
  confirm the latest CIM App 4.20 or higher is installed and the latest TA for the
  endpoint product.
known_false_positives: Although unlikely, some legitimate applications may use a moved
  copy of mshta.exe, but never renamed, triggering a false positive.
references:
- https://github.com/redcanaryco/AtomicTestHarnesses
- https://redcanary.com/blog/introducing-atomictestharnesses/
tags:
  analytic_story:
  - Suspicious MSHTA Activity
  - Living Off The Land
  asset_type: Endpoint
  confidence: 100
  impact: 80
  message: The following $process_name$ has been identified as renamed, spawning from
    $parent_process_name$.
  mitre_attack_id:
  - T1218
  - T1218.005
  observable:
  - name: user
    type: User
    role:
    - Victim
  - name: Computer
    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/T1218.005/atomic_red_team/windows-sysmon.log
    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
    sourcetype: xmlwineventlog