What is "trojan horse"

fifth column \fifth` col"umn\, n. [from a statement during the Spanish Civil War (1936) that the Falange had four columns of soldiers marching on the city, and a fifth column ``already there'' (i.e. sympathizers inside the Republican lines).]

1. a group of persons inside the battle lines of a territory engaged in a conflict, who secretly sympathize with the enemy, and who engage in espionage or sabotage; -- sometimes also referred to as a trojan horse.

2. Hence, any faction of persons within a group who secretly sympathize with an enemy, especially those who engage in activities harmful to the group; an enemy in one's midst; a group of traitors.

In computing, Trojan horse, or Trojan, is any malicious computer program which is used to hack into a computer by misleading users of its true intent. The term is derived from the Ancient Greek story of the wooden horse that was used to help Greek troops invade the city of Troy by stealth.

Trojans are generally spread by some form of social engineering, for example where a user is duped into executing an e-mail attachment disguised to be unsuspicious, (e.g., a routine form to be filled in), or by drive-by download. Although their payload can be anything, many modern forms act as a backdoor, contacting a controller which can then have unauthorized access to the affected computer.this infection allows an attacker to access users' personal information such as banking information, passwords, or personal identity (IP address).

Unlike computer viruses and worms, Trojans generally do not attempt to inject themselves into other files or otherwise propagate themselves.

The Trojan Horse is a tale from the Trojan War about the subterfuge that the Greeks used to enter the city of Troy and won the war. In the canonical version, after a fruitless 10-year siege, the Greeks constructed a huge wooden horse, and hid a select force of men inside. The Greeks pretended to sail away, and the Trojans pulled the horse into their city as a victory trophy. That night the Greek force crept out of the horse and opened the gates for the rest of the Greek army, which had sailed back under cover of night. The Greeks entered and destroyed the city of Troy, decisively ending the war.

Metaphorically a "Trojan Horse" has come to mean any trick or stratagem that causes a target to invite a foe into a securely protected bastion or place. A malicious computer program which tricks users into willingly running it is also called a "Trojan horse".

The main ancient source for the story is the Aeneid of Virgil, a Latin epic poem from the time of Augustus. The event is also referred to in Homer's Iliad. In the Greek tradition, the horse is called the "Wooden Horse" (Δούρειος Ἵππος, Doúreios Híppos, in the Homeric Ionic dialect).

The Trojan Horse, according to legend, was a giant hollow horse in which Greeks hid to gain entrance to Troy.

Trojan Horse may also refer to:

• Trojan horse (business), a business offer that appears to be a good deal but is not
• Trojan horse (computing), a computer program that appears harmless but is harmful

"Trojan Horse" is the fifth single by the Dutch girl group Luv', released in autumn 1978 by Philips/ Phonogram Records. This million seller appears on the German version of the group's first album, With Luv' (1978). and was a successful hit record in a large part of continental Europe, South Africa and New Zealand. It was a minor hit in Australia and Canada.

In business, a trojan horse is an advertising offer made by a company that is designed to draw potential customers by offering them cash or something of value for acceptance, but following acceptance, the buyer is forced to spend a much larger amount of money, either by being signed into a lengthy contract, from which exit is difficult, or by having money automatically drawn in some other method. The harmful consequences faced by the customer may include spending far above market rate, large amount of debt, or identity theft.

The term, which originated in New England during the 2000s, and has spread to some other parts of the United States, is also sometimes misused in reference to an item offered seemingly at a bargain price. But through fine print and other hidden trick, the item is ultimately sold at above market rate.

Some of the items involved in trojan horse sales include cash, gift cards or merchandise viewed as a high-ticket item, but the item actually being given away is made cheaply, has a very low value, and does not satisfy the expectations of the recipient. Meanwhile, the victim of the trojan horse is likely to end up spending far more money over time, either through continual withdrawals from the customer's bank account, charges to a debit or credit card, or add-ons to a bill that must be paid in order to avoid loss of an object or service of prime importance (such as a house, car, or phone line).

Victims of trojan horses include poor people or those who are searching for bargains or the best price on an item. Many of these victims end up with overdrawn accounts or over-the-limit on their credit cards due to fees that are automatically charged. Some of the businesses using trojan horse marketing include banks, internet and cell phone service providers, record and book clubs and other companies in which the customer will be expected to have a continuing relationship. Banks often offer cash initially for opening an account, but later charge fees in much larger amounts to the account holder. Auto-manufacturers and car dealerships will often advertise free or subsidized gas to car buyers for a certain amount of time, but increase the cost of the car in other ways. Cell phone companies use trojan horse marketing by attempting to sell items like ringtones to customers, who unknowingly are sold many more ringtones over time.

Trojan Horse is the twentieth episode of the third series of the 1960s cult British spy-fi television series The Avengers, starring Patrick Macnee and Honor Blackman. It originally aired on ABC on 8 February 1964. The episode was directed by Laurence Bourne and written by Malcolm Hulke.