Windows: Detect mstsc.exe Remote Desktop connection via /v flag

title: "Windows: Detect mstsc.exe Remote Desktop connection via /v flag"
id: d06539c0-e6cb-4a50-8ab3-9b8e2245558c
status: test
description: "This rule flags process creations where mstsc.exe is executed with the /v flag, indicating an attempt to initiate an RDP connection to a specified remote host. Attackers can use valid credentials to establish RDP sessions and then act as the logged-on user. The detection relies on Windows process creation telemetry, matching the mstsc.exe executable and the presence of the /v: argument in the command line, while excluding WSL-related mstsc activity."
references:
  - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1021.001/T1021.001.md#t1021001---remote-desktop-protocol
  - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/mstsc
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_mstsc_remote_connection.yml
author: frack113, Huntrule Team
date: 2022-01-07
modified: 2024-06-04
tags:
  - attack.lateral-movement
  - attack.t1021.001
logsource:
  category: process_creation
  product: windows
detection:
  selection_img:
    - Image|endswith: \mstsc.exe
    - OriginalFileName: mstsc.exe
  selection_cli:
    CommandLine|contains|windash: " /v:"
  filter_optional_wsl:
    ParentImage: C:\Windows\System32\lxss\wslhost.exe
    CommandLine|contains: C:\ProgramData\Microsoft\WSL\wslg.rdp
  condition: all of selection_* and not 1 of filter_optional_*
falsepositives:
  - WSL (Windows Sub System For Linux)
level: medium
license: DRL-1.1
related:
  - id: 954f0af7-62dd-418f-b3df-a84bc2c7a774
    type: derived