Yeah, isn't this the PITS?! I've done virus scans on my computer and it's clean, but the way that this new one works is that it chooses a random address in someone's address book and uses that _address_ to send out virused emails, so that the virus can't be tracked down to the person who's really infected! But from what I can tell, it's not sending to people in MY address book!!
But yes, PLEASE be careful about opening anything, especially if it has any type of weird subject line....