Information technology (IT) threats remain a growing source of concern and financial loss for companies. Viruses infect countless machines requiring extensive time in both troubleshooting and cleaning the infected systems -- but also in lost employee productivity. Worms propagate through corporate networks bringing legitimate network traffic to a halt. Hackers consistently find new ways to penetrate business information infrastructures to use resources without authorization, deface Web sites and steal proprietary information. Unfortunately, most companies do not have the advanced warning to prevent these types of attacks, but can only respond after the fact.