The dual meaning of 木马 (mùmǎ) is a perfect example of how language evolves to accommodate new technology. The modern meaning, “Trojan horse virus,” is a direct loan translation (calque) from English, which itself uses the term metaphorically. The story of the Trojan Horse from Homer's Iliad is globally recognized. When malicious software that disguised itself as a legitimate program appeared, the English-speaking world named it a “Trojan horse.” Chinese speakers adopted the same metaphor by translating its literal components: a horse made of wood. The official name for the myth is 特洛伊木马 (Tèluòyī mùmǎ), or “Troy wooden horse.” This contrasts with how some concepts are translated. Instead of creating a new, abstract scientific term, Chinese opted for a direct, descriptive one that relies on a shared global cultural story. It shows how modern digital vocabulary is often a blend of local linguistic roots and international cultural references. The innocent meaning of a rocking horse provides a stark, almost poetic contrast to its sinister digital counterpart.
The usage of 木马 (mùmǎ) is sharply divided by context. It is almost never ambiguous in a real conversation.
The connotation is neutral for the toy and strongly negative for the virus. The term is informal in both contexts.
This use of 中 (zhòng) is the same as in 中奖 (zhòngjiǎng, to win a prize) or 中毒 (zhòngdú, to be poisoned). It implies an external agent affecting you.