It's strange that men should take up crime when there are so many legal ways to be dishonest.--SUNSHINE MAGAZINE
TROJAN HORSES ARE NAMED AFTER THE FAMOUS RUSE IN WHICH THE ANCIENT GREEKS LEFT A GIANT WOODEN HORSE BY THE GATES OF TROY AND SAILED AWAY AS IF THEY HAD GIVEN UP AFTER TEN LONG AND GRUELING YEARS OF WAR. Thinking the Trojan horse was a gift to the gods and a symbol of the Greek defeat, the people of Troy pulled the horse into their city. Later that night, Greek soldiers—who had been hiding inside the wooden horse—snuck out, attacked the Trojan guards, and opened the gates of the city to their returning army.
In the computer world, a Trojan horse is any program that masquerades as something else while concealing its true purpose. The main difference between a virus, a worm, and a Trojan horse is that a Trojan horse cannot spread by itself, but instead relies on unwary users to spread it far and wide.