Trojan Horse
Etymology
From the wooden horse of Greek legend, recounted in Virgil’s "Aeneid" and Homer’s "Odyssey": the Greeks feigned retreat and left a giant horse outside Troy, which the Trojans dragged inside — unaware it concealed soldiers who opened the gates by night. The image gave computing its "Trojan," malware disguised as harmless software. Both senses turn on a defense defeated by invitation, not by force.
noun phrase · /TROH-juhn HORS/
Something welcomed in that secretly carries a hostile or harmful payload.
What it names
Use it for any gift, offer, or program that gets past defenses precisely because it looks benign.
Example
The free app was a Trojan horse, quietly harvesting contacts once installed.
Related idea
A poison pill is a defense you plant to make yourself unpalatable to an attacker; a Trojan horse is an attack disguised as something you want to take in.
noun · /TROH-juhn HORS/
In computing, malicious software disguised as something legitimate that a user is tricked into installing.
What it names
a “Trojan,” one common form of malware.
Example
The free game was a Trojan horse that quietly stole his passwords.
Related idea
A digital descendant of the myth — see malware.
See also