What is a Backdoor?
A backdoor is a piece of software to bypass login procedures, thus giving the person who spread the backdoor, full access to your system. Having a backdoor exposes your computer to the internet in a seriously threatning way.
How does a backdoor work? Basically it opens your computer to anyone who knows your computer is infected. This usually happens by exploiting bugs in the operating system or just by installing and running itself. There are two types of backdoors:
- Backdoor/trojan, the backdoor is part of a program, or a file is infected. Once you launch the file, the backdoor is installed. The program only runs when the infected file/program is run and spreads itself using the infected computer like a trojan does
- Backdoor/worm, the backdoor is launched while booting and thus runs continually when the computer is turned on. Some of these backdoors login to an irc room so your computer, and thousands of infected others, can be used for different purposes like DDos-Attacks (Distributed Denial of Service)
You can quite easily prevent backdoors with a good firewall, so you'll notice strange traffic and a good virusscan. Also take a look at the other security tips. When you suspect you've got a backdoor, go here