Types of Trojan Horse Viruses

In previous articles we described the Trojan horse virus and briefly presented the history of the malware. In this article you will learn about the types of Trojans. It is worth mentioning that each Trojan horse serves a different purpose. There are Trojan horse viruses that can perform several functions or help hacker download more computer viruses on the infected system.

1. The Remote Administration Trojan Horse Virus

This type of Trojan horse virus gives hacker behind the malware the possibility to gain control over the infected system. Often the remote administration Trojan horse virus functions without being identified. It can help the hacker to perform different functions including altering the registry, uploading or downloading of files, interrupting different types of communications between the infected computer and other machines.

2. The File Serving Trojan Horse Virus

Trojan horse viruses from this category are able to create a file server on the infected machine. Usually this server is configured as an FTP server and with its help the intruder will be able to control network connections, upload and download various files. These Trojan horse viruses are rather small in size, sometimes not more than 10Kb, which makes it difficult to detect them. They are often attached to emails or hidden in other files that users may download from the Internet. Regularly these Trojan viruses spread with the help of funny forwarded messages that a user receives from friends. Trojan horse viruses may also be hidden in small downloadable games.

3. Distributed Denial of Service Attack Trojan Horse Virus

A lot of computers can be tricked intro installing the Distributed Denial of Service Trojan so that the hacker can gain control over one, several or all computers through a client that is connected with a master server. Using the primary computer within one huge zombie network of machines, hackers are able to sent attacks at particular targets, including companies and websites. They simply flood the target server with traffic, thus making it impossible for simple users to access certain websites or systems. Often these attacks are used to stop the activity of famous brands that could handle different financial demands.

4. Keylogging Trojan Horse Virus

These Trojan horse viruses make use of spyware with the goal of recording every step of user's activity on the computer. They are called keylogging because they transmit to the hacker via email the information about logged and recorded keystrokes. Hackers use this type of malware for their financial benefit (through card fraud or identity theft). Some individuals or companies can offer a great reward for valuable information.

5. The Password Stealing Trojan Horse Virus

The name speaks for itself - Trojans from this category are used to steal passwords. The Trojan transmits information about passwords to the hacker through email. Just like keylogging Trojans, this malware is used mainly for hacker's financial benefit (a lot of people use passwords to access their bank accounts or credit cards).

6. The System Killing Trojan Horse Virus

These Trojans are meant to destroy everything in the system starting with drive Z and ending with drive A. One of the recent Trojan horse viruses of this type is called Trojan.Killfiles.904. The reasons for creating such Trojans are unknown but the results could be catastrophic.