Sigma rule: New Port Forwarding Rule Added Via Netsh.EXE

Rule

Title

New Port Forwarding Rule Added Via Netsh.EXE

Status

test

Level

medium

Author

Florian Roth (Nextron Systems), omkar72, oscd.community, Swachchhanda Shrawan Poudel

Date

2019-01-29

Modified

2023-09-01

File

rules/windows/process_creation/proc_creation_win_netsh_port_forwarding.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects the execution of netsh commands that configure a new port forwarding (PortProxy) rule

Log source

product

windows

category

process_creation

Detection

selection_img:
    - Image|endswith: '\netsh.exe'
    - OriginalFileName: 'netsh.exe'
selection_cli_1:
    CommandLine|contains|all:
        - 'interface'
        - 'portproxy'
        - 'add'
        - 'v4tov4'
selection_cli_2:
    CommandLine|contains|all:
        # Example: netsh I p a v l=8001 listena=127.0.0.1 connectp=80 c=192.168.1.1
        - 'i ' # interface
        - 'p ' # portproxy
        - 'a ' # add
        - 'v ' # v4tov4
selection_cli_3:
    CommandLine|contains|all:
        - 'connectp'
        - 'listena'
        - 'c='
condition: selection_img and 1 of selection_cli_*

False positives (as the rule lists them)

• Legitimate administration activity
• WSL2 network bridge PowerShell script used for WSL/Kubernetes/Docker (e.g. https://github.com/microsoft/WSL/issues/4150#issuecomment-504209723)

Tags

• attack.lateral-movement
• attack.command-and-control
• attack.t1090

MITRE ATT&CK ids this rule names

• T1090

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/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_netsh_port_forwarding.yml