When was the first horse discovered?

The Word 'Trojan horse' is generally attributed to Daniel Edwards of the NSA. He is given credit for identifying the attack form in the report "Computer Security Technology Planning Study". The term comes from analogy to an episode during the legendary Trojan War, as mentioned in Homer's Odyssey and Virgil's Aeneid: worn out by the long siege, the attacking Greeks built a giant wooden horse, ostensibly a peace offering, and pretended to sail away, but in fact left soldiers hidden inside the statue. After the Trojans brought the horse inside the city walls, the soldiers emerged, opened the gates to the Greek armies, and sacked the city of Troy. A very classic example, is due to computer pioneer Ken Thompson in his 1983 ACM Turing Award lecture. Thompson noted that it is possible to add code to the UNIX "login" command that would accept either the intended encrypted passWord or a particular known passWord, allowing a back door into the system with the latter passWord.