I was just checking out the intrusion logs on this site and i was wondering, what exactly are http shells? It seem that every intrusion attempt says that it was an http shell. So this has me wondering if some of the "attacks" arent false alarms. Once again i dont have any idea because i dont know what http shells are.

I tried to search google for http shells but all i came up with are *nix shells. Would someone please tell me what is trying to be done when i see http shells in the intrusion logs?

thanks.