1. A program that appears desirable but actually contains something harmful
   "when he downloaded the free game, it turned out to be a trojan horse";
   - trojan

1. A large hollow wooden figure of a horse (filled with Greek soldiers) left by the Greeks outside Troy during the Trojan War
   - Wooden Horse

1. A subversive group that supports the enemy and engages in espionage or sabotage; an enemy in your midst
   "The resistance movement feared Trojan horse activities";
   - fifth column

Derived forms: trojan horses, Trojan Horses

Type of: figure, malevolent program, malware, social unit, unit

Encyclopedia: Trojan horse