Forensic investigations of notorious internet attacks, such as the SQL Slammer and Blaster Worms, reveal buffer overflows to be the sophisticated hacker's "vulnerability of choice." These worms crippled the internet and cost billions of dollars to clean up. Now, even more powerful and insidious threats have appeared in the form of "custom exploits." These one-time-only exploits are custom crafted to attack your enterprise, making them even more difficult to detect and defend. No catchy names, no media coverage; just your own personal disaster.