Trojans: What they are and what they do.

Trojans:                   

(Coined by MIT-hacker-turned-NSA-spook Dan Edwards) A malicious, security-breaking program that is disguised as something benign, such as a directory lister, archiver, game, or (in one notorious 1990 case on the Mac) a program to find and destroy viruses! A Trojan horse is similar to a back door.

See also RFC 1135 .

A trojan, is an executable program used for a specific purpose. My experience and knowledge of trojans has led me to believe that when you execute or "run" these programs, they hide themselves on your computer (and usually are not visible thru ctrl-alt-del method of seeing active applications running). These programs are ususlly used for harmful intention like a remote back door into your system.

Trojans can be used as a back door trojan into your system, allowing people to access your computer via a network. The network usually must support the TCP/IP protocol, like the internet. A trojan usually consists of two parts, 1) the client part 2) the server part.To install the server the server simply needs to be executed. When the server executable is run, it installs itself and then deletes itself.

1) The client-part is the program a "hacker" would use to connect to your computer. All he/she needs to do this is find a computer that has had the server part installed on it. This can be done with scanners that search for infected users or a contact list in ICQ of infected people. See the ICQ section in Security Risks for more information on how you are open to this method if you use ICQ.

2) The server-part is the program which must be running on your computer for the "hacker" to connect to you. The trojan's server is installed by running it (It is a .exe file) on the target computer (eg. your computer). By default it usually installs itself in the system so that it starts automatically every time Windows starts. You don't see server-part running because it hides itself automatically at start-up.Somebody might install it on your computer without your knowledge, or you might run the program itself or a program that installs it.

3) Other forms of "social engineering" can be used to trick users into installing or running Trojan horses. For example, an intruder might telephone a system administrator and pose as a legitimate user of the system who needs assistance of some kind. The system administrator might then be tricked into running a program of the intruder's design.

What do Trojans Do ?

They install themselves on your computer, and Do many things actually, the most common being: stealing your password. but even more scary, allowing a foreign host to log onto your computer without your knowledge, and upload, delete, download your files.

Can I protect Myself ?

Sure you can! There are patches for some of the Trojan's , and programs for others, than you can install and then detect trojans in your computer or people trying to use them on your computer. To be the safest, be wary of files you download from a suspect site. Below are links to different types and maker of trojans, giving you information on what they could do to you, how to detect them and how to remove them.

ACK Tunneling Trojans