New PowerShell Instance Created — Sigma Rule

Rule metadata and linked tags

Author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research). Source status: test; severity: informational. Source dates: 2019-09-12 / 2023-11-30.

{
  "product": "windows",
  "category": "pipe_created",
  "definition": "Note that you have to configure logging for Named Pipe Events in Sysmon config (Event ID 17 and Event ID 18). The basic configuration is in popular sysmon configuration (https://github.com/SwiftOnSecurity/sysmon-config), but it is worth verifying. You can also use other repo, e.g. https://github.com/Neo23x0/sysmon-config, https://github.com/olafhartong/sysmon-modular. How to test detection? You can check powershell script from this site https://svch0st.medium.com/guide-to-named-pipes-and-hunting-for-cobalt-strike-pipes-dc46b2c5f575"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: e539b45c9eb41cb8d0f0aa689ea99276fd22d9217006ca2256069eb946ccabc8

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: New PowerShell Instance Created
id: ac7102b4-9e1e-4802-9b4f-17c5524c015c
related:
    - id: 58cb02d5-78ce-4692-b3e1-dce850aae41a
      type: derived
status: test
description: Detects the execution of PowerShell via the creation of a named pipe starting with PSHost
references:
    - https://threathunterplaybook.com/hunts/windows/190610-PwshAlternateHosts/notebook.html
    - https://threathunterplaybook.com/hunts/windows/190410-LocalPwshExecution/notebook.html
author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research)
date: 2019-09-12
modified: 2023-11-30
tags:
    - attack.execution
    - attack.t1059.001
logsource:
    product: windows
    category: pipe_created
    definition: 'Note that you have to configure logging for Named Pipe Events in Sysmon config (Event ID 17 and Event ID 18). The basic configuration is in popular sysmon configuration (https://github.com/SwiftOnSecurity/sysmon-config), but it is worth verifying. You can also use other repo, e.g. https://github.com/Neo23x0/sysmon-config, https://github.com/olafhartong/sysmon-modular. How to test detection? You can check powershell script from this site https://svch0st.medium.com/guide-to-named-pipes-and-hunting-for-cobalt-strike-pipes-dc46b2c5f575'
detection:
    selection:
        PipeName|startswith: '\PSHost'
    condition: selection
falsepositives:
    - Likely
level: informational

Original YAML and metadata in JSON

False positives

• Likely

Source references

• https://threathunterplaybook.com/hunts/windows/190610-PwshAlternateHosts/notebook.html
• https://threathunterplaybook.com/hunts/windows/190410-LocalPwshExecution/notebook.html