Indirect Command Execution via SFTP ProxyCommand — Sigma Rule

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

title: Indirect Command Execution via SFTP ProxyCommand
id: 762bb580-79b4-40f4-8b9e-9349ce1710f4
status: experimental
description: |
    Detects the use of SFTP.exe to execute commands indirectly via ProxyCommand parameter.
    Threat actors were seen leveraging this legitimate Windows binary to bypass security controls and execute arbitrary commands while evading detection.
references:
    - https://lolbas-project.github.io/lolbas/Binaries/Sftp/
    - https://news.sophos.com/en-us/2025/05/09/lumma-stealer-coming-and-going/
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2026-04-27
tags:
    - attack.stealth
    - attack.t1202
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\sftp.exe'
        CommandLine|contains: 'ProxyCommand='
    condition: selection
falsepositives:
    - Legitimate use of SFTP with proxy commands for administration or networking tasks
level: medium
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_lolbin_sftp_indirect_cmd_execution/info.yml