Potential Linux SSH X11 Forwardingedit
This rule monitors for X11 forwarding via SSH. X11 forwarding is a feature that allows users to run graphical applications on a remote server and display the application’s graphical user interface on their local machine. Attackers can abuse X11 forwarding for tunneling their GUI-based tools, pivot through compromised systems, and create covert communication channels, enabling lateral movement and facilitating remote control of systems within a network.
Rule type: eql
Rule indices:
- logs-endpoint.events.*
Severity: low
Risk score: 21
Runs every: 60m
Searches indices from: now-119m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Domain: Endpoint
- OS: Linux
- Use Case: Threat Detection
- Tactic: Command and Control
- Data Source: Elastic Defend
- Rule Type: BBR
Version: 1
Rule authors:
- Elastic
Rule license: Elastic License v2
Rule queryedit
process where host.os.type == "linux" and event.action == "exec" and event.type == "start" and
process.name in ("ssh", "sshd") and process.args in ("-X", "-Y") and process.args_count >= 3 and
process.parent.name in ("bash", "dash", "ash", "sh", "tcsh", "csh", "zsh", "ksh", "fish")
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Command and Control
- ID: TA0011
- Reference URL: https://attack.mitre.org/tactics/TA0011/
-
Technique:
- Name: Protocol Tunneling
- ID: T1572
- Reference URL: https://attack.mitre.org/techniques/T1572/