What is a Trojan Horse?

A Trojan horse program is a malicious program that pretends to be a benign application; a Trojan horse program purposefully does something the user does not expect. Trojans are not viruses since they do not replicate, but Trojan horse programs can be just as destructive.  more

Named for a giant horse that was supposed to be a gift but was filled with the Greek army, a Trojan horse program can be just as deceptive. The story goes that the Greeks gave the Trojans a huge wooden horse as a peace offering. The citizens of Troy accepted the gift, brought the horse inside the city, threw a victory bash, then went to bed. It wasn't until the Greek soldiers had set the city on fire that they realized they'd been had. A Trojan horse that affects computers can contain some nasty surprises as well. It can damage, delete, or destroy important files. A Trojan horse may actually appear to be a useful application, which is why so many unsuspecting people download them. A Trojan horse might be disguised as a program intended to rid your computer of viruses, yet actually be used to infect your system instead. While the terms "virus" and "Trojan horse" are frequently used interchangeably, they are actually quite different. A virus replicates itself, while a Trojan horse does ...  more

A Trojan horse program is a malicious program that pretends to be a benign application; a Trojan horse program purposefully does something the user does not expect. Trojans are not viruses since they do not replicate, but Trojan horse programs can be just as destructive. Many people use the term to refer only to non-replicating malicious programs, thus making a distinction between Trojans and viruses.

A Trojan horse is simply a normal computer program. The program is intended to damage only one computer. They do not spread to other files on a computer. A Trojan horse is simply a program with a single destructive payload. This might range from deleting a user’s hard drive to emailing sensitive information from a target computer back to the virus. A Trojan horse may also be used as a "remote control." This remote control allows the writer of the program to control the infected computer over the Internet.  more

A Trojan horse program is a malicious program that pretends to be a benign application; a Trojan horse program purposefully does something the user does not expect. Trojans are closely related to computer viruses, but they are not viruses since they do not replicate, but Trojan horse programs can be just as destructive. Many people use the term to refer only to non-replicating malicious programs, thus making a distinction between Trojans and viruses.  more

Virus has become a generic term for any malicious code. There is a kind of malicious code called a Trojan Horse. You may guess from the name that it is an application that appears benign, but contains a malicious payload. One, of many, possible scenario is that someone using that computer downloaded some application which appeared to be benign, but was from an untrustworthy source, acted as Trojan Horse which contained BO2K as it's payload. Thus running this seemingly benign software would result in the payload being delivered without the users knowledge. This is why it's extremely important to be careful about running applications downloaded from anywhere. Running a virus scanner at all times that checks files as they are downloaded or viewed from a remote site is a really good idea if one is downloading any kind of applications. Many of these scanners watch not only files already on the hard drive but also check files as they are downloaded, attached to e-mail and even executable ...  more

A Trojan horse is a program that tricks you into running it by being presented as something else. Most e-mail worms rely on a trojan horse, an attached file, to get into your computer.  more

Trojan horses are impostors—files that claim to be something desirable but, in fact, are malicious. A very important distinction between Trojan horse programs and true viruses is that they do not replicate themselves. Trojan horses contain malicious code that when triggered cause loss, or even theft, of data. For a Trojan horse to spread, you must invite these programs onto your computers; for example, by opening an email attachment or downloading and running a file from the Internet. Trojan.Vundo is a Trojan horse. What is a worm? Worms are programs that replicate themselves from system to system without the use of a host file. This is in contrast to viruses, which requires the spreading of an infected host file. Although worms generally exist inside of other files, often Word or Excel documents, there is a difference between how worms and viruses use the host file. Usually the worm will release a document that already has the "worm" macro inside the document. The entire document ...  more

Just as the mythological Trojan Horse appeared to be a gift, but turned out to contain Greek soldiers who overtook the city of Troy, today's Trojan Horses are computer programs that appear to be useful software, but instead they compromise your security and cause a lot of damage. A recent Trojan Horse came in the form of an e-mail that included attachments claiming to be Microsoft security updates, but turned out to be viruses that attempted to disable antivirus and firewall software. Trojan Horse (n.) A computer program that appears to be useful but that actually does damage. Trojan Horses spread when people are lured into opening a program because they think it comes from a legitimate source. Trojan Horses can also be included in software that you download for free. Never download software from a source that you don't trust.  more

Trojan horse attacks pose one of the most serious threats to computer security. If you were referred here, you may have not only been attacked but may also be attacking others unknowingly. This page will teach you how to avoid falling prey to them, and how to repair the damage if you already did. According to legend, the Greeks won the Trojan war by hiding in a huge, hollow wooden horse to sneak into the fortified city of Troy. In today's computer world, a Trojan horse is defined as a "malicious, security-breaking program that is disguised as something benign". For example, you download what appears to be a movie or music file, but when you click on it, you unleash a dangerous program that erases your disk, sends your credit card numbers and passwords to a stranger, or lets that stranger hijack your computer to commit illegal denial of service attacks like those that have virtually crippled the DALnet IRC network for months on end. The following general information applies to all ...  more