Trojan Horse (computing)


A Trojan horse is a computer program which contains malicious or harmful coding. The name "Trojan Horse" originally comes from the Greek myth Trojan horse, which explains how a Trojan horse actually behaves, as it pretends to be friendly and peaceful, when it is fact very deadly.Trojan horses are often classed as a “computer virus” when they are in fact it is a well written, purpose built, computer program.

Purpose of a Trojan Horse

Trojan horses are normally embedded inside other harmless programs, as to appear as harmless, which is then downloaded by the unsuspecting user.Once downloaded, the Trojan horse can then begin its task which it has been programmed to do. Originally, Trojan horses were created to trick users by an authentication method that required them to insert their password into a program which they believed was genuine. The Trojan would then save the password and take the users identity and send the information back to the original programmer. Nowadays Trojans are more advanced and actually look like legitimate programs that creates copies of itself.

Types of Trojan Horses

  • Keylogging

A keylogging trojan works by logging every key press made by the user, it then sends the stored key presses back to the owner of the trojan. These key logs may contain the users passwords and user names.

  • Data Corruption

Data corruption Trojans are programmed to harm the users computer. These can corrupt files and data on the users computer, and may even cause.

  • Remoter Access

Remote access Trojans installs a remote access point on the end users computer, also known as a "backdoor". This allows the programmer to gain access into the users data and personal files on there computer system.

From the moment a Trojan virus enters your computer it allows access for a possible invasion. Trojans are popular on online transactions because they are easy to use, they basically operate as a file making the person who is sending (a hacker) it having full control of the computer of the person who receives it. The moment the Trojan file gets into the victims computer it hides itself usually in some other folder or file.

It is common for a person to receive emails from some stranger saying on the subject field that it is a picture or some other type of file, these emails usually contain Trojans. It is also common for the email to require an activation of some pluggin and this also can contain a Trojan. [2]


[1] Wikipedia (2010) Trojan Horse (computing) [Online] (accessed 4/3/2010)

[2] Wise Geek(2010) What is a Trojan Horse? [Online] (accessed 4/3/2010)

[3] Gathier, J. (2012). The Effects of the Trojan Horse. [ONLINE] Available at: [Accessed 05 March 13].

Liliana Pereira

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License