http://www.caida.org/analysis/security/witty/

Exploited blackICE and other ISS software - evil! :)

<edit> also, it's the first widespread worm that actually damages systems it infects.

This is definitely not the first wide-spread worm with a damaging payload.

I think it's dependant on the term widespread. I think they said (and I incorrectly repeated) that it's the fastest widespread worm with a damaging payload. It peaked at 45 minutes (although Slammer was something like 8 minutes, but that's different).