Suspicious Plink Port Forwarding

SIGMA detection rule by Florian Roth (Nextron Systems) · NOASSERTION

Detects suspicious Plink tunnel port forwarding to a local port

title: Suspicious Plink Port Forwarding
id: 48a61b29-389f-4032-b317-b30de6b95314
status: test
description: Detects suspicious Plink tunnel port forwarding to a local port
references:
    - https://www.real-sec.com/2019/04/bypassing-network-restrictions-through-rdp-tunneling/
    - https://medium.com/@informationsecurity/remote-ssh-tunneling-with-plink-exe-7831072b3d7d
author: Florian Roth (Nextron Systems)
date: 2021-01-19
modified: 2022-10-09
tags:
    - attack.command-and-control
    - attack.t1572
    - attack.lateral-movement
    - attack.t1021.001
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Description: 'Command-line SSH, Telnet, and Rlogin client'
        CommandLine|contains: ' -R '
    condition: selection
falsepositives:
    - Administrative activity using a remote port forwarding to a local port
level: high

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

0d8aad0d-b78d-4764-86d9-73d0ea4c274f

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Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

Rejected pattern present

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Format & documentation suggestions

Not a security issue — this rule is valid and was accepted as-is. These are optional fields/conventions its own format recommends, mainly affecting its quality score and how well it documents itself for other reviewers.

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