Ok I ever so commonly hear the phrase "trojan horse virus" and is bothers me to actually hear people say this. Maybe I am wrong, and so commonly I am, but after reading part of a book called "computer viruses, worms, data diddlers, killer programs, and other threats to your system" my definition of trojan horse wasn't a virus, but a program that carried virii into a system. I may be wrong, but here is the passage from the book, you tell me what you think, and if I am just being anal about this.

Trojan Horses

Trojan Horses are often confused with viruses and worms because the latter two also infiltrate systems and can cause massive destruction of data. Indeed, worm and virus programs can be concealed within a Trojan Horse. The term is used to describe a destructive program that has been disguised as an innocent one. Trojan Horses are not viruses because they do not reproduce themselves ans spread in the way that viruses do.
When Greek warriors concealed themselves in an attractive wooden horse and left it outside the gates of the beseiged city of Troy, the Trojans assumed it was a friendly peace offering and took it in. The Greek warriors then leaped out and wreaked havok. A computer Trojan Horse works on exactly the same principle. It seems both attractive and innocent, inviting the computer user to load the program. The Trojan Horse may be in the form of a game or some other software that the victim will be tempted to try out. Members of the Inner CIrcle hackers' club once created a Trojan Horse chess program that they played with the system operator who discovered they had broken into the Canadian mainframe computer he was guarding. The operator thought he had been clever in catching the hackers and that there was no harm in continuning a dialogue with them in the form of a chess match. He was wrong. All the time that the computerized chess match was going on, the hacker's Trojan Horse enabled them to access accounts of increasing importance. Another popular medium for Trojan Horses is attractive graphics programs, including the pornographic games, which are disseminated widely on bulletin boards.
Examples of Trojan Horses are legion. They were around long before viruses became a far more serious problem and ave been used to get into very high level accounts, including those containing passwords and other crucial data about the computer's security procedures.
A New Jersey executive copied a graphics enhancing program form a Long Island bulletin board. It proved to be a Trojan Horse that destroyed 900 programs on his system. It displayed the brutal message, "Arf, arf! Got you!" Usually, Trojan Horses are much more subtle, especially when they are used for embezzlement or industrial espionage. They can be programmed to self-destruct, to leave no evidence behind except the damage they have caused. A Trojan Horse is particularly effective for the common computer crime of "salami slicing," in which small sums unlikely to be noticed are sliced off a number of legitimate accounts and moved to a secret account being operated by the thief.

This is not my article I just read it and thought I would share it. I do have one question though, when I run a virus scan on my computer, and it detects a Trojan Horse, does that mean it found a "destructive program that has been disguised as an innocent one" or the virus/s it contains?