The Witty worm is a computer worm that attacks the firewall an other computer security products written by a particular company, Internet Security Systems (ISS). It was the first worm to take advantage of vulnerabilities in the very pieces of software designed to enhance network security, and carried a destructive payload, unlike previous worms. It is so named because the phrase "(^.^) insert witty message here (^.^)" appears in the worm's payload.