It's a Trojan virus..
which runs a variat of this virus:
Which is harmless in and of itself because all it does is open a port, mask it and allow traffic to pass through uninhibited. This is otherwise known as a backdoor. This is a foot in the door for any baddies out there to get into your system and really cause some problems for you.
You can all thank Sony Music for flat out screwing you.
BTW, California has filed a class action lawsuit on 3 counts of consumer protection laws. New York is expected to announce a similar class action suit later today. You can also expect a few other states and consumer rights organizations to jump on the bandwagon. If you thought Sony was hurtin' before, this is gonna absolutly kill them.