New Remote Desktop Connection Initiated Via Mstsc.EXE — Sigma Rule

Rule metadata and linked tags

Author: frack113. Source status: test; severity: medium. Source dates: 2022-01-07 / 2024-06-04.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 9ac7304ab946b2c1c0693bd02c681c1239286cd6cbaa8df8c5f8751c562ca9e8

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: New Remote Desktop Connection Initiated Via Mstsc.EXE
id: 954f0af7-62dd-418f-b3df-a84bc2c7a774
status: test
description: |
    Detects the usage of "mstsc.exe" with the "/v" flag to initiate a connection to a remote server.
    Adversaries may use valid accounts to log into a computer using the Remote Desktop Protocol (RDP). The adversary may then perform actions as the logged-on user.
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
author: frack113
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:
        # Example: mstsc.exe /v:XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX /hvsocketserviceid:XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX /silent /wslg /plugin:WSLDVC /wslgsharedmemorypath:WSL\XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX\wslg C:\ProgramData\Microsoft\WSL\wslg.rdp
        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

Original YAML and metadata in JSON

False positives

• WSL (Windows Sub System For Linux)

Source 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