Want to know how fast Slammer (a.k.a. Sapphire/SQL Slammer) proliferated? "This worm required roughly 10 minutes to spread worldwide making it by far the fastest worm to date. In the early stages the worm was doubling in size every 8.5 seconds. At its peak, achieved approximately 3 minutes after it was released, Sapphire scanned the net at over 55 million IP addresses per second." Nicholas Weaver and his team at UC Berkeley have a fascinating report on SQL Slammer at http://www.cs.berkeley.edu/~nweaver/sapphire/