How did a Trojan get its name ?

The name "Trojan" originates from the ancient Greek story of the Trojan Horse. Since the ancient Greeks could not infiltrate the city of Troy using traditional warfare methods, they gifted the king of Troy with a big wooden horse with hidden soldiers inside and eventually defeated him. Borrowing the concept, a Trojan is malware that looks like legitimate software, and once it tricks a user into installing it, it acts much like a virus or worm.