Who This Book Is For

I have written this book with two types of reader in mind. The first are those of you with a professional interest in computer security. The traditional focus of this field has been on preventing attacks on private machines and networks from people and viruses, and using computer forensics to reveal their activities.

But today's threats require that we go beyond this localized, internal focus and look outward to the Internet. Some of the viruses we see are used to set up email relay servers that are used by international spam operations. Computers are attacked, hijacked, and used to host fake bank web sites that are used for identity theft. Those of you who are computer security professionals will learn the core techniques you need in order to address this evolving type of threat.

The larger, less defined, audience consists of software developers and systems administrators who take a broad interest in the Internet and how it works. Many of us feel a deep frustration with the epidemics of spam, phishing, and viruses and want to fight back against it in some way. The book will show you how the bad guys are able to abuse the technology of the Internet. It will show you how to uncover information about their operations and, in doing so, make their lives a lot more difficult.

To get the most out of this book, it helps to have a working knowledge of Unix and some experience with Perl. But that is not an absolute requirement. If you can use a web browser and an email client, then you can follow along with most of the material in the book. You already have the most important thing you need: an inquisitive mind.

I have tried to avoid complex software as far as possible. Most of the tools come standard with recent versions of Linux and those that don't are easily downloaded and installed. I have included Perl scripts throughout the book where these can help automate common tasks or help display information more concisely, and I have made a conscious effort to keep these scripts short and simple. My hope is that they are easy to understand and can serve as starting points for your own scripts.