A relay path is a communication route that forwards data through an intermediate node or layer instead of sending it directly to the destination. In cyber security, this can mean traffic is passed through another device, server, proxy, or mesh node before reaching a command-and-control system, a cloud service, or an operator.
Relay paths matter because they can hide the real source and destination of traffic, complicate attribution, and bypass simple network controls that assume direct connections. Attackers use them to move stolen data, proxy commands, or keep communication working across restricted networks. Defenders look for unusual hop patterns, repeated forwarding behavior, mismatched source addresses, and encrypted traffic flowing through unexpected intermediaries. In mobile malware, a relay path may be used to exfiltrate data through nearby devices or local infrastructure, making containment harder than with a single direct outbound connection.