A Trojan horse is a type of malware. It s hidden in a computer program, and after installation, a Trojan horse provides criminals with unnoticed access to your computer. It is a kind of backdoor that can be used by malicious people to secretly gain control over your computer and files. This is also where the name Trojan horse comes from; it is a reference to the Trojan Horse, which was used by the Greeks to open the gates of Troy from the inside for a large-scale invasion.
How do you catch a Trojan horse?
There are several ways in which your computer can become infected with a Trojan horse. For example, this can happen through an attachment to an email. Trojan horses are also often hidden in pornographic material, spread through chat programs and lurk in files on torrent networks. Often, as a user, you will not immediately notice that your computer has been infected by a Trojan horse. In all discretion, malicious people can access your files while you don’t notice. The hackers who gain access to your PC can, among other things, copy, edit and delete files on your hard disk.
The consequences of infection with a Trojan horse
If your computer is infected with a Trojan horse, your computer can be taken over by hackers/criminals. These criminals can for example:
- Steal, alter or destroy files.
- Find out passwords and login information.
- Use your PC to attack other networks or servers (e.g., by means of a DDos attack).
- Use your PC to routinely attack other networks or servers
- Causing the computer to systematically crash.
- Take over the operating system.
- Record keystrokes.
- Visiting websites with your PC.
- Making your computer part of a large-scale botnet.
Difference between Trojan horse, virus and worm
A virus operates independently after activation and, for example, causes damage to an infected computer. A Trojan horse does not cause any damage by itself; it only allows criminals to enter your computer unnoticed. The extent of the damage depends on what actions the criminals then perform on your computer. It is possible that a virus carries a Trojan horse; your computer is then infected with a virus and at the same time the Trojan horse provides hackers with access to your computer. A Trojan horse does not spread independently over a network as is the case with a computer worm, for example.
Preventing Trojan horses
Some tips to reduce the chances of being infected by a Trojan horse are:
- Always use good antivirus software. Anti-virus software usually also tackles Trojans.
- Do not open any suspicious emails. Be careful which files you download and open. It is always worthwhile to scan files with anti-malware software, although a good antivirus scanner will automatically warn you when you want to open an infected file.
- If your computer is now infected with a Trojan horse, perform a complete virus scan of your computer. Most decent antivirus software will recognize the Trojan horse and remove the threat.