The Worm That Ate the Web - The latest version of Conficker isn't the first bot to plague the Internet, but it may be the smartest and most sophistica

Last week, I pulled out my Internet cable, unplugged my USB drives, and searched my Windows machine for Conficker, the astounding computer worm that threatens to wreak global havoc once its latest version begins to phone home for further instructions on April 1. Well, maybe: While security researchers warn that the worm's creators may be planning on conducting fraud or even "information warfare" aimed at disrupting the Internet, nobody knows what terrible deed Conficker will ultimately pull off. What we do know is that Conficker is devilishly smart, terrifically contagious, and evolving. Each time experts discover a way to constrain its spread, its creators release new, more sophisticated versions that can push even further. The latest version, Conficker C, hit the Internet early in March. Estimates aren't precise, but researchers say the worm—in all its variants—has so far infected more than 10 million machines around the world.
Conficker gets into Windows through a security hole that Microsoft fixed last fall. As a result, the worm tends to run rampant on networks where IT guys have been slow to patch people's machines (like at the British Parliament, for instance, which reported a Conficker infection last week). Countries with lots of pirated versions of Windows are also vulnerable, with China, Brazil, Russia, and India among the most Confickered nations. On the other hand, I was lucky—my computer was worm-free. If your machine has been properly patched and protected, there's a good chance it's safe, too. (See Symantec's page on how to detect and remove it.)