Early yesterday morning, a new worm dubbed Witty appeared and it is moving quickly. Unlike other worms which exist to propagate themselves, Witty has shown the ability to corrupt hard drives and crash PCs. The attacks come from UDP source port 4000.
Security experts say the best way to get rid of this worm is to reboot the computer it infects. Since the worm exploits a hole in BlackIce Version 3.6 ccf and ecf, it is best to unplug computers using that software from the internet.
According to Lurhq Corporation, Witty can wreck a computer's operating system and other files. The longer Witty is on one's PC, the more damage it does. Network operators report that Witty tried to connect yesterday at a rate of 200 times a minute. Source