A honeypot is a "dummy" target machine set up to observe hacker attacks. A honeynet is a network built around such dummy machines in order to lure and track hackers as they step through the attack process. By studying real-world attacks, researchers hope to predict emerging trends in order to develop defenses in advance. This chapter reviews honeypots and walks you through the steps for constructing your own Linux-based honeynet.
Lance Spitzner, the founder of one such tracking endeavor known as the Honeynet Project (http://project.honeynet.org), defines a honeypot as "a security resource whose value lies in being probed, attacked or compromised." The goal of such a masochistic system is to be compromised and abused. Hopefully, each time a honeypot goes up in smoke, the researcher learns a new technique. For example, you can use a honeypot to find new rootkits, exploits, or backdoors before they become mainstream.
Running a honeynet infrastructure is similar to running a spy network deep behind enemy lines. You have to build defenses and also be able to hide and dodge attacks that you cannot defend against, all the while keeping a low profile on the network. It is important to be able to safely study the computer underground from a distance. Instead of going to them, they come to you. Additionally, honeypot stories can be edifying. For example, a researcher relates this tale:
One intruder broke in to a honeypot and deployed his toolkit packaged as his-hacker-nickname.tar.gz ...