The Windows Live Messenger service is now under attack by the latest worm called Heartworm. The previous worm that did damage on their IM service was called Pipeline, which secretly delivers an executable file disguised as a JPEG that then installs rootkits and Trojans on systems running AOL’s Instant Messenger service. Heartworm with its real name W32.heartworm.a, affects users of Microsoft’s Windows Live Messenger service (formerly MSN Messenger), presenting users with a link to a Web site that tells them a virtual greeting card is waiting for them.

According to computerworld :

That link brings unsuspecting users to an image of a heart with a poem written in Portuguese, which secretly installs files on the user’s PC that record personal and financial information. According to FaceTime researchers, who wrote about Heartworm in a Sept. 22 blog posting, the heart-shaped message appears to be hosted on a site dedicated to exposing online hoaxes, perhaps in an attempt to encourage visitors to click through.