ABSTRACT
They grab headlines as they cut a wide swath of destruction through corporate America: viruses, worms
(such as Code Red and Nimda), and hackers. The unfortunate fact is that even in organizations with
extensive deployment of firewall, encryption, and intrusion detection systems (IDS), attacks still occur
with alarming frequency. According to a Computer Security Institute/FBI survey of Fortune 1000
organizations that have suffered attacks, 91 percent had deployed firewalls and 61 percent had
installed IDS.
