To confuse you even more:
http://www.forums.alientrap.local/viewtopic.php?t=2351
See this thread how you can get the latest development version of Nexuiz for Windows, how to compile it on your own, and you'll see, that this game has no built in trojan or whatever.
Note, that a lot anti-virus are using a so called "heuristics", and maybe your AVG has got a false report because of this.
Also, Nexuiz 2.3 is outdated like it's stated above, get 2.4.2 as that's the newest version.
Trust me, I'm playing this game since 1.0, I've played every versions since then, I've built my own on my linux box from the source code, and since pure addiction, Nexuiz has never casused any harm
