Thanks to my good friend dwergs of https://www.mess.be ...
A new network virus called Worm.Win32.Smbmsn.163840 was discovered two days ago by Asia-based Global Hauri. This worm spreads through MSN Messenger through a file called SMB.EXE. If the user accepts this file, it will send itself to all contacts on his or her contact list. If the user executes it, a DOS prompt will come up for about a second and disappears. This occurs because it unzips a couple of files to the C: root and windows directories. The file also tempers with the registry (see below for details).
Do NOT accept the file transfer of SMB.EXE (or any other suspicious file) in MSN Messenger!
An MSN spokesperson said the company is aware of the virus, and that users" best means of protection is to have a desktop anti-virus solution already installed, and to use MSN Messenger 6"s anti-virus feature. The feature enables customers to link their desktop anti-virus software to the IM client, automatically scanning incoming files for viruses.
Read more for info on how to remove to worm ...