WebSocket tunneling is the practice of carrying arbitrary network traffic inside WebSocket or secure WebSocket (WSS) sessions. WebSockets are meant for persistent browser-to-server communication, so the resulting traffic can blend in with ordinary web activity and avoid some simple network filters.
In cyber security, this technique matters because it can hide command channels, proxy connections, or reverse tunnels inside traffic that looks like normal application behavior. Attackers may use it to reach internal services through a compromised host, move data out quietly, or keep control channels open with fewer obvious signatures than classic VPNs or SSH tunnels. Defenders look for unusual WebSocket endpoints, long-lived connections from systems that do not normally use them, and payload patterns that do not match the expected application. WebSocket tunneling is not malicious by itself, but in intrusion tradecraft it is often a concealment layer that makes detection and traffic analysis harder.