“What is a Trojan Horse?” is a very good question to ask - especially since it is one of the most common, yet most difficult-to-tackle computer threats. Getting its name from the mythical Trojan horse, it’s every bit as tricky and dangerous. A Trojan horse virus is actually disguised as a useful program or software. However, once executed, it will begin to do a lot of damage to your computer.
How does it Work?
After you know “What is a Trojan Horse?” you need to understand how it works. A Trojan horse hides among some useful software in your computer, so you can’t detect it. There are different kinds of Trojan horses that are designed to do anything from causing minor inconvenience to a complete crash down of the system.
Some Trojans open a “back door” which allows hackers free access to your system while others delete all your files on the system and destroy any information you may have stored; some cause minor annoyance like randomly playing around with your computer’s settings and changing the look of your desktop; and yet others leak confidential information out.
How Do Trojan Horses Spread?
Along with knowing “What is a Trojan Horse?” it is equally important to know how they spread. It’s not possible for them to spread all by themselves. They are dependent on various other forms of distribution such as downloads from websites or exchanging content on file sharing and P2P software. Another common mode by which Trojans spread is through emails containing attachments. Chat software such as Skype and Yahoo Messenger are also preferred by Trojan horses to infect other computers.
Types of Trojan Horses:
Now that you have the answer to the question “What is a Trojan horse?” let’s look at the various types of Trojan Horses.
• Remote Access Trojans or RATs: These Trojans provide the attacker with control over the system of an unsuspecting user. The attacker then has the power to access all kinds of personal files on the victim’s computer such as private information, accounting data, private conversations etc.
• Trojans that send Data: These Trojan horses provide personal and sensitive information like passwords, e-mail addresses, information related to credit cards or IM contact lists.
• Destructive Trojans: They are designed to do only one thing -automatically destroy and delete all the files on a computer.
• Proxy Trojans: They allow the attacker to turn the victim’s computer into a proxy server, allowing him to do anything he wants from your computer (usually illegal and fraudulent activities). All activities will look as if the victim was the one doing them.
In addition to these, there are several other kinds of Trojans: Mail-Bomb Trojans, keyloggers, Denial of Service (DoS) Attack Trojans, Security Software Disabler Trojan, FTP Trojans.
