Suspicious PsExec Execution - Zeek

 1title: Suspicious PsExec Execution - Zeek
 2id: f1b3a22a-45e6-4004-afb5-4291f9c21166
 3related:
 4    - id: c462f537-a1e3-41a6-b5fc-b2c2cef9bf82
 5      type: derived
 6status: test
 7description: 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
 8references:
 9    - https://blog.menasec.net/2019/02/threat-hunting-3-detecting-psexec.html
10author: Samir Bousseaden, @neu5ron, Tim Shelton
11date: 2020/04/02
12modified: 2022/12/27
13tags:
14    - attack.lateral_movement
15    - attack.t1021.002
16logsource:
17    product: zeek
18    service: smb_files
19detection:
20    selection:
21        path|contains|all:
22            - '\\'
23            - '\IPC$'
24        name|endswith:
25            - '-stdin'
26            - '-stdout'
27            - '-stderr'
28    filter:
29        name|startswith: 'PSEXESVC'
30    condition: selection and not filter
31falsepositives:
32    - Unknown
33level: high