What is a Trojan Horse

What is a Trojan horse?

A Trojan horse (often called “Trojan”), is a malicious program that pretends to be a legitimate one. Below are a few examples of Trojan horses:

- A user receives an email that appears to be from a friend or a well-known organization such as a university or a bank, when in fact the email is originating from an unknown person that tries to ask the user for their credentials;

- A user receives a file that looks like a picture or a song, but when they try to open that file by double-clicking on it, it seems like nothing happened. If that file was a Trojan horse, chances are that the user has installed a nasty program onto their hard drive without even noticing. Some of these nasty programs can allow other people unlawful access to the user’s computer, whereas others might start randomly deleting system files and rendering their operating system unusable.

People commonly believe that it is enough to install anti-virus software to be protected against Trojan horses. But in reality, anti-virus software should mainly be used to protect the system from viruses, and does not offer a complete protection from Trojan horses, simply because a virus and a Trojan are not the same. Several third-party malware protection software can purchased or downloaded and installed and used to detect Trojan horses.

Who is at risk?

More and more computers nowadays are connected to the internet. And since the internet connection is a two-way channel, it enables you to upload data to the internet, and at the same time data gets stored on your computer from the internet. People need to know that not all the data stored on their machines is data that they have requested, and this is when problems can start to happen.

Computers that are not at risk from Trojans are the ones that do not have a modem, do not connect to the internet (whether via cable, modem, or wireless connection), do not connect to any network and doesn’t have a CD-ROM, DVD-ROM, or any external drive connection. Realistically, any computer is at risk of being infected with Trojans because any computer should have the ability of receiving files, at least from a CD or a DVD or even a floppy drive for very old systems! Computers connected to the internet are at a higher risk because they connect to the outside world and can receive the Trojan via email, the web, by downloading a file from a website, etc.

Protection against Trojans

To protect computers and information systems from Trojans, computer and network administrators should install and configure anti-Trojan software

Anti-Trojan software is software designed to detect and capture Trojans as well as other forms of malware. To detect existing malware, the Anti-Trojan software will first perform a scan on the hard drive and remove any Trojan files it finds. Most anti-malware software have also got a background guard component which can be used to constantly watch for new infections with malware or Trojans and block them before they become active. And to ensure continued protection of the computer systems against new Trojans which keep appearing on a regular basis, it is important to keep the Anti-Trojan software up to date by downloading online updates.

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