The name escapes me for the moment, but there was a famous computer virus which I believe did almost to do that. They key wasn't that it was particularly clever and the attack vector it used had been patched by MS months before.

The key was that the attack happened over UDP which meant that there was no handshake, no congestion control, no need to worry about dropped packets, etc. The only limitation was the bandwidth of the infected host -- the virus itself was less than 500 bytes (not kilo, just straight bytes) so a single host could infect tens of millions of computers.

It was a pretty fascination piece of malware.

You're talking about SQL Slammer. The whole virus fit in a single UDP packet. Wired had a pretty good (if slightly sensational) writeup at the time:

http://www.wired.com/wired/archive/11.07/slammer.html

Code Red http://en.wikipedia.org/wiki/Code_Red_(computer_worm) did a lot of damage, but I believe it was an attack on IIS, therefor TCP based.

It wasn't code Red. It was latter and attacked a database discovery service for MSSQL.

Relevant: http://en.wikipedia.org/wiki/Robert_Tappan_Morris Also: http://en.wikipedia.org/wiki/Morris_worm