I really wouldn't worry about this..It sounds like the work of sub seven or some other script kiddie tool..Most of those skiddie 9x tools let you change the background and open cd drives and stuff of that immature nature..Your best bet is to go to www.simplysup.org and download the free trial of trojan remover, then scan your system with it..Firewall all of your machines and lock them down anyway possible...Hope this helps..