Today is the anniversary of the Mydoom.A outbreak - the worst email outbreak in the history.
This incident, which started on January 26th 2004, bypassed even the Sobig.F epidemic of 2003. At its worst, a major part of all email traffic globally was caused by Mydoom.A. The worm generated over 100 million emails just during the first day of the outbreak.
Mydoom performed a denial-of-service attack on www.sco.com between February 1st and 12th, 2004. This attack, which was arguably the largest DDoS case in history, kept the target website down for weeks.
We first warned about the Mydoom worm on January 26th, at 23:05 GMT by issuing a Radar Level 2 Alert. About four minutes later we shipped detection for the worm. The Radar Level was raised to Radar Level 1 three hours later. This is the highest level we have.
Following Mydoom.A there was the infamous virus war between the Mydoom, Bagle and Netsky.