MSN Problem - Funny Faces

Someone sent me a message with attachment. I opened that file and since then my MSN has infected with virus.
It automatically creates funny faces four times in a row when ever I send one message. Unfortunately I don't see that faces at all and onlyreceiver sees these on his screen.
At the bottom of MSN screen (Status Bar)where message with user name comes I see the name of GEORGE BUSH with whitehouse.gov coming automatically and sending faces.
Any one aware of this virus problem and how I can get rid of it.