Can you get viruses from the games on Steam?

[Kimchi]

I play Counter Strike: Source and Half Life 2: Deathmatch before and I now have the games on my Mac via Steam; when I used to play on Windows I would often download custom maps in-game (I would join a server and it would automatically download the map) and I am a bit concerned of this because I am now wondering, is that a safe thing to do? Since I have a Mac I am worried that I might get a virus or something from these 'foreign' maps I am downloading (I downloaded one but deleted it after). Is it possible to get viruses, spyware, malware, etc. from downloading in-game maps on games from Steam?

I'm hoping you would say "No, you can't get viruses from downloading maps in-game. Don't worry about it" or something like that LoL.

P.S. In case you were wondering what map I downloaded it was bm_flatgrass or gm_flatgrass I think.

[Pocket]

Is it possible to put viruses in custom map files? Possibly. You can theoretically hide a virus in anything, but it won't work unless there's a bug in the program that opens it (the Source engine, in this case) that allows data to escape into other parts of the computer. It's pretty rare that you see these kinds of security holes crop up, and it's usually in formats like PDF that let people embed all kinds of crazy stuff by design.

But a virus in a custom map would have another hurdle to get over: the fact that servers always compare their copy of the map with the users'. Once you download a custom map, it's on your computer until you decide to remove it manually. So if you log into another server that also runs that map, it'll see that you already have it and jump right on without downloading anything. You with me so far? Now, let's say you own your own server, and you have a copy of a popular map, and you decide to wreak havoc by sticking a virus into it. Uh-oh, now it's different from the version every other server has, so anyone who already has that map won't be able to play it on your server. And everyone who downloads it from your server won't be able to play it anywhere else. People will get suspicious and the next thing you know, people have figured out that there's a virus and traced it to your server.

So basically the only way a map could get away with having a virus in it would be if the original creator put it there. And in that case, it would also only be a matter of time before people trace it to the source and that map is no longer used by any reputable servers.

[Jim Bond]

No, there are no known virus's that you can get from custom maps and game files for the mac.