What is a Trojan?

Linx · Guest Status: Add Rep 0

What is a Trojan?

Ever hear the story about the Trojan horse where the Greek armies surrounded the city of troy. They made a huge hollow wooden horse to house their army. Darkness fell and the city of Troy took in this wooden horse as a gift. In the middle of the night the army left the horse and slayed the city in their sleep.

Im not implying that a Trojan can kill people but it does work along similar lines.

A Trojan is simply a sort of remote control that can be installed on a machine and allow a user to enter and exit the target system by leaving a port open on the PC. Dependant upon the Trojan used, users can have access and control over almost everything including opening and closing the CD tray turning the monitor on and off, hijacking the mouse and most importantly data thieving.

Some of the more common Trojans are:

• SUB7 – Possibly the most widely used, however this is a very common Trojan and most virus scanners will pick up on it
• NetBus – More professional appearance and you now have to pay for it. Still gets picked up by most virus scanners.
• Back Orifice – Never really used it so I cant comment.
• Win VNC – Principles of a Trojan however can only be used whilst on the network

Trojans can be installed in various ways without you knowing:

1. The IPC$ share exploit 
2. Embedding VBS/Java script into the body of HTML to automatically download and install the server
3. Combined files. The hacker can mix the server together with, lets say, a picture file so when the mark opens the file, they see the picture yet don’t know they have been infected.

Trojans are a networks admins worst nightmare. Where as the beginner hacker will only obtain a few files from the targets PC with a Trojan installed its like there sitting at the terminal.

Linx Laughing