Welcome to the endlessly fascinating exploration of computers, networks, phones and technology that is the world of hacking. Whether you are an Internet newbie curious to know what all the media headlines are really about, a computer enthusiast wanting to know more about how the Internet works, or an average Internet user, this book will demystify the subject of hacking by describing how hacking works.

Before beginning to hack, it might be a good idea to find out a little about computers and networking (*doh*). Anyone who already has a firm grasp of the basic principles of computing in the 21st century can happily skip this chapter, or dip into it as they wish.

Any attempt to write the history of hacking, to chart the rise and fall of hacker groups, their Bulletin Board Systems (BBS), electronic magazines ("ezines" or "zines") and fantastic exploits across the globe is going to be incomplete. It has to be, as hacker history is being re-written almost daily, the curiosity and drive of the hacker forcing them always to find new techniques to explore, new technologies to master.

This chapter describes some of the many tools used for hacking and phreaking that are floating around on BBSs and the Internet. Please note that things change so quickly in the world of hacking that new tools and even new categories of tools could appear before this book comes into print.

The nature of computing has changed so rapidly in the last few years that by the beginning of the 21st century many techniques common to hackers working in the 1980s or even early 1990s have become obsolete overnight. Consider the Internet connection, once only available to students, academics, and dedicated hackers.

Sometimes black-hat hackers decide that there is no alternative but to take the direct approach to the systems they are interested in. The direct approach consists of three basic techniques to gather information about the target system; Trashing, to gather basic information. Social Engineering, to gather more advanced information, and Infiltration Hacking, where information is gained by actual physical entry into the target building.

Once anyone begins to start getting serious about computers, they soon find all sorts of different systems available to learn about and play with.

The phone system is the largest network on the planet, spanning thousands of miles, covering almost every country and location from the busiest cities to far flung Indian villages. It is also the largest machine ever built by human beings, a machine in the sense that it is a single object, designed for a simple purpose, but which is distributed across the planet.

A computer virus is a program which intentionally makes copies of itself. It may contain some sort of "payload", which can be destructive or non-destructive program code, that is activated and run when certain conditions are fulfilled.

There are three uses of the Internet in the 21st century which generate the most discussion/flamage/negative publicity/lost bandwidth. The most well known of these is Internet porn, a subject which is beyond the scope of this book, while the other two are the trading of MP3 files and the distribution of pirated software.

Welcome to the most "black hat" chapter in the book, devoted to exposing the black art of "cracking" computer security. Understanding how crackers work is vital to any systems administrator, as they need to understand that before a cracker starts trying to breach the system security of remote systems, the cracker already understands *why* they want to gain access.

Having made it this far through the book, you might be wondering how to protect yourself from all this stuff, so this chapter is dedicated to a discussion of some fundamental security measures that you might want to take.

A collection of links, and references papers and books.