You're question is a little bit vague, don't you think? Something along the lines of "what device should I use to cook with?" The answer will vary depending on what you want to do exactly. May I suggest you read the first link in my signature below?
As for malware, in general Linux doesn't have much of a problem with that. There are almost no linux-targeting viruses/worms in the wild. As long as you obey good online safety practices you're unlikely to get infected. But there are AV systems that can be used on Linux, mostly to clean up the mess of Windows-based worms.
ClamAV is the most commonly-used, I believe. AVG also provides
a version of their AV for linux.
