Malware
Belonard
Once set up in the system, Trojan.Belonard replaces the list of available game servers in the game client and creates proxies on the infected computer to spread the Trojan.
Belonard is a Windows malware family.
Background
After installing itself, Trojan.Belonard swaps out the game client's list of available servers and turns the compromised machine into a proxy used to propagate the Trojan. Because these proxy servers typically report a lower ping, they appear near the top of the list for other players. When a player picks one, they are sent to a malicious server that infects their computer with Trojan.Belonard.
Source: Malpedia (Fraunhofer FKIE).