All new Ø-day. David Litchfield is a world-renowned security expert specializing in Windows NT and Internet security. His discovery and remediation of over 100 major vulnerabilities in products such as Microsoft's Internet Information Server and Oracle's Application Server have lead to the tightening of sites around the world. David Litchfield is also the author of Cerberus' Internet Scanner (previously NTInfoscan), one of the world's most popular free vulnerability scanners. In addition to CIS, David has written many other utilities to help identify and fix security holes. David is the author of many technical documents on security issues including his tutorial on Exploiting Windows NT Buffer Overruns referenced in the book "Hacking Exposed".