PsExec Tool Execution From Suspicious Locations - PipeName — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: medium. Source dates: 2022-08-04 / 2023-09-20.

{
  "category": "pipe_created",
  "product": "windows",
  "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: c097cd5facb6e79504635b658ba8b169680a75c6a03ddd2a744f310d32cae932

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: PsExec Tool Execution From Suspicious Locations - PipeName
id: 41504465-5e3a-4a5b-a5b4-2a0baadd4463
related:
    - id: f3f3a972-f982-40ad-b63c-bca6afdfad7c
      type: derived
status: test
description: Detects PsExec default pipe creation where the image executed is located in a suspicious location. Which could indicate that the tool is being used in an attack
references:
    - https://www.jpcert.or.jp/english/pub/sr/ir_research.html
    - https://jpcertcc.github.io/ToolAnalysisResultSheet
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-08-04
modified: 2023-09-20
tags:
    - attack.execution
    - attack.t1569.002
    - attack.s0029
logsource:
    category: pipe_created
    product: windows
    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: '\PSEXESVC'
        Image|contains: # Add or remove locations depending on how and if you execute Psexec in your env
            - ':\Users\Public\'
            - ':\Windows\Temp\'
            - '\AppData\Local\Temp\'
            - '\Desktop\'
            - '\Downloads\'
    condition: selection
falsepositives:
    - Rare legitimate use of psexec from the locations mentioned above. This will require initial tuning based on your environment.
level: medium

Original YAML and metadata in JSON

False positives

• Rare legitimate use of psexec from the locations mentioned above. This will require initial tuning based on your environment.

Source references

• https://www.jpcert.or.jp/english/pub/sr/ir_research.html
• https://jpcertcc.github.io/ToolAnalysisResultSheet