Suspicious PsExec Execution - Zeek — Sigma Rule

Rule metadata and linked tags

Author: Samir Bousseaden, @neu5ron, Tim Shelton. Source status: test; severity: high. Source dates: 2020-04-02 / 2022-12-27.

{
  "product": "zeek",
  "service": "smb_files"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 77394605b30a8318f7b5d130e81ff94a9f74bf4fd7c3e56778120a44cb0ac523

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: Suspicious PsExec Execution - Zeek
id: f1b3a22a-45e6-4004-afb5-4291f9c21166
related:
    - id: c462f537-a1e3-41a6-b5fc-b2c2cef9bf82
      type: derived
status: test
description: detects execution of psexec or paexec with renamed service name, this rule helps to filter out the noise if psexec is used for legit purposes or if attacker uses a different psexec client other than sysinternal one
references:
    - https://web.archive.org/web/20230329171218/https://blog.menasec.net/2019/02/threat-hunting-3-detecting-psexec.html
author: Samir Bousseaden, @neu5ron, Tim Shelton
date: 2020-04-02
modified: 2022-12-27
tags:
    - attack.lateral-movement
    - attack.t1021.002
logsource:
    product: zeek
    service: smb_files
detection:
    selection:
        path|contains|all:
            - '\\'
            - '\IPC$'
        name|endswith:
            - '-stdin'
            - '-stdout'
            - '-stderr'
    filter:
        name|startswith: 'PSEXESVC'
    condition: selection and not filter
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://web.archive.org/web/20230329171218/https://blog.menasec.net/2019/02/threat-hunting-3-detecting-psexec.html