Potential Remote Desktop Tunneling

Hunt Hypothesis

Detects potential use of an SSH utility to establish RDP over a reverse SSH Tunnel. This can be used by attackers to enable routing of network packets that would otherwise not reach their intended des

Detection Rule

Sigma (Original)

title: Potential Remote Desktop Tunneling
id: 8a3038e8-9c9d-46f8-b184-66234a160f6f
status: test
description: Detects potential use of an SSH utility to establish RDP over a reverse SSH Tunnel. This can be used by attackers to enable routing of network packets that would otherwise not reach their intended destination.
references:
    - https://www.elastic.co/guide/en/security/current/potential-remote-desktop-tunneling-detected.html
author: Tim Rauch, Elastic (idea)
date: 2022-09-27
tags:
    - attack.lateral-movement
    - attack.t1021
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains: ':3389' # RDP port and usual SSH tunneling related switches in command line
    selection_opt:
        CommandLine|contains:
            - ' -L '
            - ' -P '
            - ' -R '
            - ' -pw '
            - ' -ssh '
    condition: all of selection*
falsepositives:
    - Unknown
level: medium

KQL (Azure Sentinel)

imProcessCreate
| where TargetProcessCommandLine contains ":3389" and (TargetProcessCommandLine contains " -L " or TargetProcessCommandLine contains " -P " or TargetProcessCommandLine contains " -R " or TargetProcessCommandLine contains " -pw " or TargetProcessCommandLine contains " -ssh ")

Required Data Sources

False Positive Guidance

• Unknown

MITRE ATT&CK Context

• Tactic: Lateral Movement
• Technique: T1021 — T1021

References

• https://www.elastic.co/guide/en/security/current/potential-remote-desktop-tunneling-detected.html
• SigmaHQ Rule