A trojan is short for a Trojan Horse, which is a historical term that applies to a very specialized type of computer program that is also known as a virus. In computers, a trojan horse is a type of malware that self replicates. It is malicious software that gives the appearance of doing something positive, but instead it is causing destruction or stealing your personal data.
There are three malicious programs that are often confused with each other. These three programs are the Trojan Horse, the Worm, and the Virus. Though they are all similar, they are not the same. The virus, much like it’s name sake, comes in a variety of strengths with different effects. The virus lives to replicate and spread itself across the Internet. They are spread by attachments or through executable files (.exe) so unless you open the attachment or run the .exe file the virus will not infect your computer. So for, the Virus to spread there must be human interaction. A Worm, on the other hand, is capable of spreading without human interaction. This makes a worm more dangerous than a virus even though the two programs are very close in how they act and what they do. The only major difference is one needs you to spread it about while the other will spread itself about on its own. A Trojan Horse, is a sneaky, conniving menace of creation that does it’s best to trick you into allowing it to install itself. Once installed it makes you think it is doing something useful, but it is stealing all of your data, destroying your computer’s operating system or both.
Still what is important to recognize here is that these programs are similar in design but may not act the same when installed.
One key difference between a Trojan and both Virus and Worms is that the Trojan does not self replicate. It relies on human error to spread, and this is where the trickery starts. Most Trojan Horse Malware is spread because the person believes they are downloading something completely different like a windows upgrade, or a music player, etc. What they get in return is malware.
A Trojan Horse might simply be designed to wreak havoc with your computer. It might delete all of your icons on your desktop or hide your music files, etc. It may be designed to destroy your computer. It is not unheard of that a Trojan Horse will enable hackers to access your computer and steal all of your personal data like financial information, passwords, and even your address.
The Trojan Horse was the downfall of Troy, and they can be the downfall of your computer. If you do not have adequate computer security systems in place, then you will become a victim sooner rather than later. There are plenty of good security systems out there, but if you are on the hunt for a great security system try Comodo.com