A proxy tool is software that relays traffic through an intermediate host instead of sending it directly between an attacker and the target. This can hide the true source of a connection, reroute commands, and support pivoting deeper into a network after compromise.
In cyber attacks, proxy tools help operators blend into normal traffic, especially when used with encrypted channels or compromised internal systems. They may forward ports, tunnel remote access, or relay file transfers so the malicious activity appears to come from a trusted machine. Defenders look for unusual internal relay behavior, unexpected listening ports, suspicious encrypted sessions, and connections that do not match the role of the host. Proxy tooling is also used defensively for controlled access, but in intrusion cases it is often a sign of stealth and lateral movement.