trojan horse

(computer security) A malicious program that is disguised as legitimate software.

(Greek mythology) The hollow wooden horse by which the Greeks allegedly gained access to Troy during the Trojan War.

(figuratively) A subversive person or device placed within the ranks of the enemy.

(business) A seemingly favorable offer designed to trick customers into making exorbitant payments.

(politics) A person, organization, social movement, piece of legislation, or ideology with a negative agenda or evil intentions under the guise of positive values or good intentions.

Alternative form of Trojan horse. [(Greek mythology) The hollow wooden horse by which the Greeks allegedly gained access to Troy during the Trojan War.]

Alternative form of Trojan-horse. [(transitive, idiomatic) To introduce slyly, to sneak in, to subvert.]