Suspicious PsExec Execution

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

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Detection logic

selection1

EventID: 5145
ShareName: \\\\\*\\IPC$
RelativeTargetName|endswith:
  - -stdin
  - -stdout
  - -stderr

filter

RelativeTargetName|startswith: PSEXESVC

Condition

selection1 and not filter

Raw YAML

title: Suspicious PsExec Execution
id: c462f537-a1e3-41a6-b5fc-b2c2cef9bf82
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
date: 2019-04-03
modified: 2022-08-11
tags:
    - attack.lateral-movement
    - attack.t1021.002
logsource:
    product: windows
    service: security
    definition: 'The advanced audit policy setting "Object Access > Audit Detailed File Share" must be configured for Success/Failure'
detection:
    selection1:
        EventID: 5145
        ShareName: '\\\\\*\\IPC$' # looking for the string \\*\IPC$
        RelativeTargetName|endswith:
            - '-stdin'
            - '-stdout'
            - '-stderr'
    filter:
        RelativeTargetName|startswith: 'PSEXESVC'
    condition: selection1 and not filter
falsepositives:
    - Unknown
level: high