trojen -
noun Also written trojan (Science and Technology) A computer program which (like a virus or worm) is designed to sabotage a computer system, but which usually breaks the security of the system by appearing to be part of a
legitimate program, only starting to erase or
retrieve data once it
has been carried successfully into the system. Also known more fully as a Trojan horse. Etymology: A reference to the Trojan horse in the Greek epic tradition: a hollow wooden horse in Homer's Iliad in which Greek soldiers concealed themselves to enter and defeat the town of Troy. Since the nineteenth century, the term Trojan horse had been applied figuratively to any person or device concealed as a trick to undermine something from within. The computing sense was the first to abbreviate this
further to Trojan (and it is perhaps surprising that this happened even in the computing
sense , since Trojan is the
trade mark of a well-known brand of contraceptive sheath in the US). History and Usage: Under the name Trojan horse, the Trojan was
first developed in the seventies by hackers (see
hack ) wanting to
gain access to other people's systems or carry out computer frauds involving the transfer of funds by computer. By the second half of the eighties, Trojans were considered
an important
hazard and special systems had been set up to detect and block
them . The Trojan may be no more than a few lines of code inserted into another (apparently useful) program; it cannot replicate itself, but once the program is running it can start carrying out
its under-cover activities, copying or destroying
data as required. In many ways, a Trojan is similar to a logic bomb except that it does not usually require a specific set of conditions to obtain before it can be activated. Among the
dozens of trojans in circulation, some begin their destruction within minutes. The Times 26 May 1987, p.
26 A perfect place to plant a Trojan horse. By changing a couple
[of] lines of code in our telnet program, he could make a password grabber. Whenever my scientists connected to a distant system, his insidious program
would stash their passwords into a secret file. Clifford Stoll The Cuckoo's Egg (1989), p. 154
