What is a Trojan Horse and How does it Attack Computers?

2008-12-08

A Little History

Trojan War is considered as the most significant conflicts in Greek mythology.

This is where Trojan horse comes into play for the first time. The great warrior Odysseus brought this strategy to find a way into the city of Troy. He commanded his army to make a massive wooden horse large enough to host several Greek soldiers in it.

Then all Greek soldiers fled from Troy except for great warrior Odysseus and several other warriors who hid inside the wooden structure.

There was another man called Sinon was sitting duck to the enemy. His duty was to make sure that the Trojans take the bate by convincing them that his fellow Greeks had betrayed him and fled from the city. He convinced the Trojans that the wooden horse left by Greeks is safe and would bring them luck.

Even though Trojans had already defeated the Greeks they still wanted more luck and decided to wheel the horse through their gates unknowingly granting the Greek enemy access to the city of Troy where all of Trojans were partying after proclaiming victory.

Without noticing the handful of great enemy hiding inside the giant horse standing in the middle of them, the citizens of Troy went to sleep after the huge parties took all over the city.

It was the hour of Odysseus and his men who were patiently waiting for the moment. They sneaked out of the horse, to which the Trojans were praying a while ago, and wreaked havoc on the city.

Back To Computer

I gave that brief idea about the history of the Trojan Horse to give you the impression of the computer Trojan Horses.

Computer Trojans are exactly as same as the first Trojan Horse. A Trojan is a small program embedded into a harmless program such as a game, animation, etc.

Trojans do not spread themselves as computer viruses. It needs the computer user to initiate it. In other words, when you try that new game you got free from a web site, the Trojan inside that gets installed into your computer without your understanding.

The worst thing is since the Trojan is executed by the computer user, Trojan gets the same set of privileges as the user does. So if you are an Administrator and you play a game with a Trojan, you grant all rights that you have to the Trojan, Just like what happened in Troy!

Most Trojans connects to its creator from the infected computer. These computer geniuses who use their skills to cause damages to the public are called Crackers. If anyone carelessly opens an untrusted program and launches a Trojan, His or her computer can be controlled by the cracker for his malicious work. These computers are called Zombie Computers because the real owner of the computer doesn’t even know that his computer is been controlled by a different party.

Crackers use networks of zombie computers to send more viruses or to get anything done. These networks are called Botnets.

How to protect yourself form Trojans?

There are very basic and simple precautions to follow:

• Never open any attachment/file sent by unknown senders
• Never open any file you receive without scanning for threats (even if it’s from a very close friend. Because he may already be a victim and can be sending Trojans with his mails without knowing)

You must have seen and heard these precautions more than you have heard or seen about threats but we never tend to follow these and that’s what crackers always want.

An Example; Trojan Horse I Made Some Time Ago…

Well, don’t take me wrong, I also have made a Trojan once but it was not to damage anyone…

When I was in my first job where I met my girl friend, before going and ask her, I wanted to run a check on her computer to see if I could find any evidence of a boy friend 🙂

At that time I already had made a TCP/IP chat software. So what I did was I made a nice animation of Winnie the Pooh and embedded a Trojan which could read the password file in her computer it was easy because she launched my Trojan with her admin rights. So while she was enjoying the Winnie the Pooh animation which I downloaded from the Internet to decoy her, my Trojan read her password file and sent all entries to my computer through TCP/IP which I could capture using my Chat Server.

Then it was only a matter of a brute force attack to get her password. I still remember her password 😀

I told her about it very soon and she was amazed to hear her password from my voice! And of course it was a plus point for me too 😀

So the conclusion I want to make here is that a Trojan is a very powerful concept which can be used by your enemies to use your own powers and privileges to take control and harm your computer and many others. So always be careful when dealing with email attachments and executable files.

Being extra cautious is always good and can protect you from many threats…!

Was this post helpful to you? How can I improve? – Your comment is highly appreciated!

Cassian Menol Razeek