Potential Protocol Tunneling via Chisel Server

Last updated a year ago on 2025-02-04

Created 2 years ago on 2023-08-23

About

This rule monitors for common command line flags leveraged by the Chisel server utility followed by a received connection within a timespan of 1 minute. Chisel is a command-line utility used for creating and managing TCP and UDP tunnels, enabling port forwarding and secure communication between machines. Attackers can abuse the Chisel utility to establish covert communication channels, bypass network restrictions, and carry out malicious activities by creating tunnels that allow unauthorized access to internal systems.

Tags

Domain: EndpointOS: LinuxUse Case: Threat DetectionTactic: Command and ControlData Source: Elastic DefendLanguage: eql

Severity

medium

Risk Score

MITRE ATT&CK™

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

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

License

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

Definition

Rule Type: Event Correlation Rule
Integration Pack: Prebuilt Security Detection Rules
Index Patterns: logs-endpoint.events.network*logs-endpoint.events.process*
Related Integrations: endpoint(external, opens in a new tab or window)
Query

✄𐘗text code block:
✄𐘗sequence by host.id, process.entity_id with maxspan=1m
  [process where host.os.type == "linux" and event.type == "start" and event.action == "exec" and 
   process.args == "server" and process.args in ("--port", "-p", "--reverse", "--backend", "--socks5") and 
   process.args_count >= 3 and process.parent.name in ("bash", "dash", "ash", "sh", "tcsh", "csh", "zsh", "ksh", "fish")]
  [network where host.os.type == "linux" and event.type == "start" and event.action == "connection_accepted" and 
   destination.ip != null and destination.ip != "127.0.0.1" and destination.ip != "::1" and 
   not process.name : (
     "python*", "php*", "perl", "ruby", "lua*", "openssl", "nc", "netcat", "ncat", "telnet", "awk", "java", "telnet",
     "ftp", "socat", "curl", "wget", "dpkg", "docker", "dockerd", "yum", "apt", "rpm", "dnf", "ssh", "sshd", "hugo")]

Install detection rules in Elastic Security

Detect Potential Protocol Tunneling via Chisel Server 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(external, opens in a new tab or window).