[Crypto Kitsune]

The original can be found here.
https://www.sinister.ly/Thread-Tutorial-...-Spreading

While this could be an effective way to build a bot net you could increase the snare by using more updated games. I know of plenty of Major games that have private server versions out floating about, World of Warcraft for example. Just use the aforementioned idea.
http://topg.org/ <- the site showing top servers and what games, rest is up to you.