LSASS Process Reconnaissance Via Findstr.EXE — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems). Source status: test; severity: high. Source dates: 2022-08-12 / 2024-06-04.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 9f046378b2567737d6e3bf02fe2cae5c7910ce00e30dd85c8e3e5fdab95b7471

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: LSASS Process Reconnaissance Via Findstr.EXE
id: fe63010f-8823-4864-a96b-a7b4a0f7b929
status: test
description: Detects findstring commands that include the keyword lsass, which indicates recon actviity for the LSASS process PID
references:
    - https://blog.talosintelligence.com/2022/08/recent-cyber-attack.html?m=1
author: Florian Roth (Nextron Systems)
date: 2022-08-12
modified: 2024-06-04
tags:
    - attack.credential-access
    - attack.t1552.006
logsource:
    category: process_creation
    product: windows
detection:
    selection_findstr_img:
        - Image|endswith:
              - '\find.exe'
              - '\findstr.exe'
        - OriginalFileName:
              - 'FIND.EXE'
              - 'FINDSTR.EXE'
    selection_findstr_cli:
        CommandLine|contains: 'lsass'
    selection_special:
        CommandLine|contains|windash:
            - ' /i "lsass'
            - ' /i lsass.exe'
            - 'findstr "lsass'
            - 'findstr lsass'
            - 'findstr.exe "lsass'
            - 'findstr.exe lsass'
    condition: all of selection_findstr_* or selection_special
falsepositives:
    - Unknown
level: high
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_findstr_lsass/info.yml

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://blog.talosintelligence.com/2022/08/recent-cyber-attack.html?m=1