There were worms that would target other worms.... (Score 2, Informative)

For the folks discussing having 'good' botnets, does anyone remember the Nachi worm? It's purpose was to use the same Windows RPC DCOM vulnerability that Lovesan (an 'evil' worm) used. It would then kill the lovesan processes and download the necessary patches from M$ to prevent further re-infection. It would then search out network segments for other machines to 'fix' Nice in concept, but the amount of network traffic that this created when it was in search mode would overwhelm closet switches in a decent sized LAN environment (minded, Lovesan did as well...). A company I was with had a branch office whose network manager was slow on patches. They got infected with both worms successively. While Nachi wiped out Lovesan (eventually), the office network was still useless until Nachi was cleaned off as well. Relying on autonomous software outside of your control to randomly secure machines is a bad idea.