This is not an April Fool's joke...
The Conficker worm has created secure infrastructure for cybercrime. The worm allows its creators to remotely install software on infected machines. What will that software do? We don’t know. Most likely the worm will be used to create a botnet that will be rented out to criminals who want to send SPAM, steal IDs and direct users to online scams and phishing sites.
The Conficker worm mostly spreads across networks. If it finds a vulnerable computer, it turns off the automatic backup service, deletes previous restore points, disables many security services, blocks access to a number of security web sites and opens infected machines to receive additional programs from the malware’s creator. The worm then tries to spread itself to other computers on the same network.
If you think you're infected with Conficker but have not patched your system yet. Fret not for thy patch is within you. Click here to download it from Symantec (the guys that made that sluggish anti virus).