Microsoft have just posted a security warning on their Windows Live blog: Security alert: Active links in Messenger 2009 temporarily turned off to prevent a malicious worm. They are alerting users that there is a malicious worm currently trying to spread itself through IM networks, including Windows Live Messenger 2009 (Wave 3).
The worm spreads by inserting a link into an IM conversation with a person whose computer is already infected. When someone clicks the link, it opens in a browser, downloads the worm on the recipient’s computer, and then repeats this process.
This however does NOT concern users of the latest version of the software – Windows Live Messenger 2011
Stay alert!
Regards
Marc Liron – Ex-Microsoft MVP (2004-2010)