A network worm is making the rounds looking for Windows computers that have file sharing enabled which activates Port 445. If a successful connection is made, the Trojan called Deloder installs a program called INST.EXE in the Start folder. This is a Trojan designed to open a back-door access to compromised computer. Full infection is accomplished when the machine is re-booted the program then tries to access other computers on the network using a list of default passwords
If the program is successful in connecting with a network share then real damage is done. Check out the full story on the [Register]