<loud annoying beep> This Is Not A Test.
There's a tapeworm crawling around the net again.
If you get a mail message with a .VBS file attached, trash the attachment, unopened. If your mail program has an "Automatically open attachments" switch, find it and turn it off. If you don't know whether it does or not, find out, or have someone find out for you.
The one I got a copy of today, off a mailing list, was LINKS2.VBS. It contains a bunch of encrypted Visual Basic code that does we know not what, including, apparently, mailing copies of itself to the first N people in your addressbook.
Let me state that again: these messages look like they came from someone you know. You still can't trust them.
Are we beginning to understand the problem, here? :-)
I've written on this topic before; page back, and you should find it. If you have a virus checker, note that it probably needs to be told that .VBS files might be a problem, see this alert from Network Associates, among others...
It would appear that this program only affects Microsoft Outlook mail addressbooks -- yet another good reason to use something else. :-)