39 percent of all Counter-Strike 1.6 game servers seen online were found to actually be malicious. Trojan used zero-days in the client to create a large botnet made up of fake game servers for the popular online multiplayer game. Players can choose to purchase a dedicated server, which allows them to have processor resources in the cloud that are dedicated to their own gameplay. Owners of game servers often try to monetize their platforms by offering various privileges, such as protection against bans, special skins and cosmetics, access to special weapons.
Source: https://threatpost.com/zero-days-counter-strike-botnet/142823/