From MediaPost (Laurie Sullivan)
A wave of fake Twitter email invitations sent in hopes of luring people to unzip a file to find out who invited them has been hitting unsuspecting victims. The message carries a mass-mailing worm. It looks around on infected computers and sends emails to addresses it finds.
The message appears as if it came from a Twitter account, but unlike a legitimate Twitter message, there is no invitation URL in the body of the email. Instead, the user sees an attachment that appears as a .zip file containing an invitation card. When the zip file is opened, the virus spreads. Read the full story [mediapost.com]