Rule of thumb would: You download a copyrighted piece of software of the Gnutella network and your AntiVirus freaks out, it's usually not a good thing.

Of course it depends on if you malware protection is any good, but I would say there is a 99% chance that it is malicious. Also since it is against the rules to ask for help here regarding how to use illegally downloaded copyright material, there is really no point in continuing this.