Most p2p sharing networks get spammed with virus'd files. Question is recognising & avoiding such files. File size is a great way to recognise them; Virus thread: Typical virus spam file sizes - Make a note of them (click on blue link to see).
Scan all files after downloading. Keep your AV program up to date with virus definitions. Here's a good page to look at too: WARNING: Viruses on network you should be aware of! (click on blue link)

BTW originally spammers only targeted copyright files. Now they target all files, since they wish the death of p2p sharing. They have no conscience. They are sponsored to do what they do; it's their professional business.