Potential Linux Tunneling and/or Port Forwarding via SSH Option

Last updated a month ago on 2025-04-25

Created a month ago on 2025-04-25

About

This rule detects the use of SSH options that may indicate tunneling or port forwarding on Linux systems. This behavior is commonly associated with malicious activity, such as establishing a port forward, proxy or an encrypted tunnel to exfiltrate data.

Tags

Domain: EndpointOS: LinuxUse Case: Threat DetectionTactic: Command and ControlData Source: Elastic DefendData Source: Elastic EndgameData Source: CrowdstrikeData Source: SentinelOneLanguage: eql

Severity

low

Risk Score

MITRE ATT&CK™

Command and Control (TA0011)(opens in a new tab or window)

↳ Protocol Tunneling (T1572)(opens in a new tab or window)

License

Elastic License v2(opens in a new tab or window)

Definition

Rule Type

Event Correlation Rule

Integration Pack

Prebuilt Security Detection Rules

Index Patterns

endgame-*logs-crowdstrike.fdr*logs-endpoint.events.process*logs-sentinel_one_cloud_funnel.*

Related Integrations

endpoint(opens in a new tab or window)

crowdstrike(opens in a new tab or window)

sentinel_one_cloud_funnel(opens in a new tab or window)

Query

process where host.os.type == "linux" and event.type == "start" and event.action in ("exec", "exec_event", "start", "ProcessRollup2") and
process.name in ("ssh", "sshd") and process.args == "-o" and
process.command_line like~ (
  "*ProxyCommand*", "*LocalForward*", "*RemoteForward*", "*DynamicForward*", "*Tunnel*", "*GatewayPorts*",
  "*ExitOnForwardFailure*", "*ProxyCommand*", "*ProxyJump*"
)

Install detection rules in Elastic Security

Detect Potential Linux Tunneling and/or Port Forwarding via SSH Option in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).