Sigma rule: Indirect Command Execution via SFTP ProxyCommand

Rule

Title

Indirect Command Execution via SFTP ProxyCommand

Status

experimental

Level

medium

Author

Swachchhanda Shrawan Poudel (Nextron Systems)

Date

2026-04-27

File

rules/windows/process_creation/proc_creation_win_sftp_proxy_command_execution.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

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.

Log source

product

windows

category

process_creation

Detection

selection:
    Image|endswith: '\sftp.exe'
    CommandLine|contains: 'ProxyCommand='
condition: selection

False positives (as the rule lists them)

• Legitimate use of SFTP with proxy commands for administration or networking tasks

Tags

• attack.stealth
• attack.t1202

MITRE ATT&CK ids this rule names

• T1202

References

• https://lolbas-project.github.io/lolbas/Binaries/Sftp/
• https://news.sophos.com/en-us/2025/05/09/lumma-stealer-coming-and-going/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_sftp_proxy_command_execution.yml