1 Introduction
Criminal computer attacks grew at an alarming rate in
2004 and are expected to continue to rise in 2005. Zero-day
attack exploits are being sold on the black market [11]. Trojan
horses and backdoors may be a significant part of those
exploits. They can cause significant damage, such as information
loss and information tampering. Even worse, many
Trojan horses and back-doors may go undetected.