This weekend, the IRC/Unity group discovered that access to computers infected by the Fizzer worm is regulated by a three-letter nickname, which is generated by an algorithm that depends on the current date. A person who knows the nickname can issue commands to any computer that's compromised by the virus and listening to the current chat channel.
Several IRC operators have started using the information to command any PC infected with the virus that connects to their network to uninstall itself.
"A lot of networks are actively sending out the command to all IRC Fizzer clients," said McGarrigle. "When they send the uninstall command, it leaves no trace of the bot."
Full article here
Using the bot itself do uninstall it, what a smart idea ....