Go into safemode and run a full AV scan (after updating your virus description) or
AVERT Stinger. This is probably a variant of W32/NoChod@MM as talked about in
!!Virus!!
I can't stress this enough:
If the first thing in a conversation is a link: don't click it!
Or atleast ask the person who send the link if they did send a link...if he/she didn't then he/she is infected with the virus/trojan/worm. These messages get send when that person signs in to all contacts on his/her list without that person knowing.