Great link Greg.

For anyone who wants the short version. This worm (not a virus) is much like Happy99 which attaches itself to your emails, without you knowing it. Once someone has it, you need to remove it manually. If you get this or other trojans, worms or virus and never open it, it can just be deleted. If you get it and have been infected, go to the link that Greg posted. You need to do some manual editing.

PrettyPark is particularily nasty because it connects to the internet and can possibly send information about you and your computer to other people.