A Trojan virus is a piece of software designed to look like a useful file or software program but performs a possibly nefarious function once installed on a client computer. The virus takes its name from the “Trojan Horse” from Greek mythology setup outside of the city of Troy. Trojan horse viruses differ from other computer viruses in that they are not designed to spread themselves. Instead Trojan horse malware is either delivered as the payload of another virus or piece of malware or through manual end-user action by downloading infected files or inserting infected drives into a computer. Once a computer is infected with a Trojan virus, the malware can be designed to steal end-user information, perform destructive harm on the target computer, or even download additional computer malware. Trojan horse viruses comprised more than 80% of all computer malware detected in the world over the past year and the number continues to grow.