Windows Scheduled Task Creation via schtasks.exe Using sshd/ssh.exe for Tunnel Setup

title: Windows Scheduled Task Creation via schtasks.exe Using sshd/ssh.exe for Tunnel Setup
id: e2e7edc9-ec88-479a-850f-90ca56506675
status: experimental
description: This rule flags process executions of schtasks.exe where the command line includes a scheduled task creation (/create) that references sshd.exe with -f or ssh.exe with -i. Such behavior can indicate an attacker setting up persistent access by periodically launching an SSH-based tunnel or service. The detection relies on Windows process creation telemetry capturing the Image/OriginalFileName and full command line arguments used to create the task.
references:
  - https://thedfirreport.com/2023/10/30/netsupport-intrusion-results-in-domain-compromise/
  - https://www.kroll.com/en/insights/publications/cyber/cactus-ransomware-prickly-new-variant-evades-detection
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_schtasks_openssh_tunnelling.yml
author: Rory Duncan, Huntrule Team
date: 2025-07-14
tags:
  - attack.privilege-escalation
  - attack.persistence
  - attack.execution
  - attack.t1053.005
  - attack.command-and-control
logsource:
  product: windows
  category: process_creation
detection:
  selection_img:
    - Image|endswith: \schtasks.exe
    - OriginalFileName: schtasks.exe
  selection_cli_sshd:
    CommandLine|contains|all:
      - " /create "
      - sshd.exe
      - -f
  selection_cli_ssh:
    CommandLine|contains|all:
      - " /create "
      - ssh.exe
      - -i
  condition: selection_img and 1 of selection_cli_*
falsepositives:
  - Unknown
level: high
license: DRL-1.1
related:
  - id: 2daa93a0-a5fb-41c5-8cd8-3c11294bfd1f
    type: derived