F-Secure, an antivirus vendor, estimates that it has seen 11 different worms today based on the MS05-039 Plug-and-Play vulnerability, including three Zotob variants (.A, .B, and .C), one Rbot (.ADB), one Sdbot (.YN), one CodBot, three IRCbots (.ES, .ET and .EX), and two variants of Bozori (.A and .B). What's fascinating is that the IRCbots and the Bozori worms are designed to remove traces of Zotob and other worms. As we've seen before, having competing malicious code on one computer can cause it to crash. Apparently, this Internet street fight is simply over ego and not a conspiracy to take down the Internet. Stay on top of the latest developments at the CNET Security Center.