From Longman Dictionary of Contemporary EnglishTrojan HorseˌTrojan ˈHorse noun 1 → the Trojan Horse2 someone or something that is accepted because it seems good or harmless, but that is really intended to cause harm Senator Simon claimed the new law would reduce violence on TV, but opponents have attacked it as being a ‘Trojan Horse’ that would lead to censorship of TV programming.From Longman Business DictionaryTrojan horseTro‧jan horse /ˌtrəʊdʒən ˈhɔːsˌtroʊdʒən ˈhɔːrs/ noun [countable usually singular]1something that looks attractive but that is intended to deceiveThe bank’s CEO described Japanese investments in the UK as a Trojan horse, destroying Europe’s defences against unfair competition.2computing a computer program that seems to be helpful but that is designed to destroy dataSecurity was breached by a Trojan horse accidentally downloaded to a government computer.