New PortProxy Registry Entry Added — Sigma Rule

Rule metadata and linked tags

Author: Andreas Hunkeler (@Karneades). Source status: test; severity: medium. Source dates: 2021-06-22 / 2024-03-25.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 77228b12b236e91000c88e131c443d1ee87e6aabb19d6497a2978df1941f2f96

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 PortProxy Registry Entry Added
id: a54f842a-3713-4b45-8c84-5f136fdebd3c
status: test
description: Detects the modification of the PortProxy registry key which is used for port forwarding.
references:
    - https://www.fireeye.com/blog/threat-research/2019/01/bypassing-network-restrictions-through-rdp-tunneling.html
    - https://adepts.of0x.cc/netsh-portproxy-code/
    - https://www.dfirnotes.net/portproxy_detection/
author: Andreas Hunkeler (@Karneades)
date: 2021-06-22
modified: 2024-03-25
tags:
    - attack.lateral-movement
    - attack.command-and-control
    - attack.t1090
logsource:
    category: registry_event
    product: windows
detection:
    selection:
        # Example: HKLM\System\CurrentControlSet\Services\PortProxy\v4tov4\tcp\0.0.0.0/1337
        TargetObject|contains: '\Services\PortProxy\v4tov4\tcp\'
    condition: selection
falsepositives:
    - WSL2 network bridge PowerShell script used for WSL/Kubernetes/Docker (e.g. https://github.com/microsoft/WSL/issues/4150#issuecomment-504209723)
    - Synergy Software KVM (https://symless.com/synergy)
level: medium

Original YAML and metadata in JSON

False positives

• WSL2 network bridge PowerShell script used for WSL/Kubernetes/Docker (e.g. https://github.com/microsoft/WSL/issues/4150#issuecomment-504209723)
• Synergy Software KVM (https://symless.com/synergy)

Source references

• https://www.fireeye.com/blog/threat-research/2019/01/bypassing-network-restrictions-through-rdp-tunneling.html
• https://adepts.of0x.cc/netsh-portproxy-code/
• https://www.dfirnotes.net/portproxy_detection/