Sigma Rule Library

LSASS Process Reconnaissance Via Findstr.EXE

Detects findstring commands that include the keyword lsass, which indicates recon actviity for the LSASS process PID

View on GitHubOpen raw file

Detection logic

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

Raw YAML

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

False positives

  • Unknown

References

Similar rules