computer software, a Trojan horse is a program that installs malicious software while under the guise of doing something else. Though not limited in their payload, Trojan horses are more notorious for installing backdoor programs which allow unauthorized remote access to the victim's machine by unwanted parties - normally with malicious intentions. Unlike a computer virus, a Trojan horse does not propagate by inserting its code into other computer files. The term is derived from the classical myth of the Trojan Horse. Like the mythical Trojan Horse, the malicious code is hidden in a computer program or other computer file which may appear to be useful, interesting, or at the very least harmless to an unsuspecting user. When this computer program or file is executed by the unsuspecting user, the malicious code is also executed resulting in the installation of the malicious Trojan horse program