name: Malicious PowerShell Process With Obfuscation Techniques
id: cde75cf6-3c7a-4dd6-af01-27cdb4511fd4
version: 5
date: '2021-01-19'
author: David Dorsey, Splunk
status: production
type: TTP
description: This search looks for PowerShell processes launched with arguments that
  have characters indicative of obfuscation on the command-line.
data_source:
- Sysmon Event ID 1
search:
  selection1:
    OriginalFileName: pwsh.dll
  selection2:
    Image|endswith:
    - pwsh.exe
    - sqlps.exe
    - sqltoolsps.exe
    - powershell.exe
    - powershell_ise.exe
  selection3:
    OriginalFileName: PowerShell.EXE
  selection4:
    OriginalFileName: powershell_ise.EXE
  condition: (selection1 or selection2 or selection3 or selection4)
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: These characters might be legitimately on the command-line,
  but it is not common.
references: []
tags:
  analytic_story:
  - Hermetic Wiper
  - Malicious PowerShell
  asset_type: Endpoint
  confidence: 60
  impact: 70
  message: Powershell.exe running with potential obfuscated arguments on $dest$
  mitre_attack_id:
  - T1059
  - T1059.001
  observable:
  - name: dest
    type: Endpoint
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  risk_score: 42
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1059.001/obfuscated_powershell/windows-sysmon.log
    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
    sourcetype: xmlwineventlog