Trojan horse. Conceptual computer artwork of a horse leaping out of a computer monitor. This could represent a computer being infected by a trojan horse computer program. A trojan horse is a program that masquerades as a benign application, but unlike a computer virus it does not replicate. Although it can still be as destructive as a computer virus, for example by deleting data. The term comes from a story in Homer's Iliad where a giant wooden horse was given to the Trojans as a peace offering by the Greeks. The horse's hollow inside contained Greek soldiers who opened the city's gates and allowed the Greeks to take Troy.