'Witty' Worm Wrecks Computers The worm targets Windows computers that run specific security firewalls. By Brian Krebs washingtonpost.com Staff Writer Saturday, March 20, 2004; 7:02 PM A quickly spreading Internet worm destroyed or damaged tens of thousands of personal computers worldwide Saturday morning by exploiting a security flaw in a firewall program designed to protect PCs from online threats, computer experts said.