The latest variant shuts down security services, blocks connections to security Web sites, downloads a Trojan, and connects to other infected computers via peer-to-peer technology. It also includes a list of 50,000 different domains to reach out to for updated copies or instructions, but only 500 of those will be contacted on April 1. Earlier versions of the worm attempted to contact 250 domains.

A quick way to tell if your computer is infected is to try to access the Web site of a major antivirus vendor, which the worm blocks.

The U.S. Department of Homeland Security has released a Conficker detection tool for government agencies and state and local governments to use that ws developed by US-CERT.

Additionally, try going to http://windowsupdate.microsoft.com -- if you can update you computer you are likely safe.