How to Use This Book

The managers of an ever-growing number of companies are beginning to see information security as an issue requiring attention, showing how much of a threat they truly believe exists. In any case, whether you work as part of the security department of a large corporation or as a system administrator with security as part of your job description, knowing how to get into your network is one of the best ways to secure it.

The first part of this book (Chapters 1–4) explains the roles and responsibilities of a penetration-testing professional and the motivation and styles of the hacking community. This information provides insight into why hacking has become so popular with the media and what difficulties are associated with protecting a network. The material is designed to provide background information to support the use of penetration testing as an important part of an overall network security plan. A penetration test not only tests the network's ability to protect information and other assets from unauthorized individuals but also can test the organization's ability to detect such intrusion attempts and its incident response capabilities. We also discuss some of the common pitfalls in technology and defenses that contribute to security weaknesses. A large portion of successful network security breeches could have been avoided if special attention had been given to these issues.

The second part of this book (Chapters 5–10) provides a structured framework for a penetration test. Penetration testing can be broken down into a series of steps that provide an efficient and comprehensive review of individual network segments. Whether the test is an internal or external review, the methodology follows the steps of discovery, scanning, and exploitation. This section outlines methods for finding the target network, identifying possible vulnerable services, exploiting weaknesses, and documenting the results. This methodology yields a test that is structured, efficient, and repeatable. In this section of the book we also introduce various tools that can be used to assist with this methodology. We briefly describe each tool's use and place in testing.

The third section of this book (Chapters 11–16) provides greater detail on the tools that can increase the speed and accuracy of a penetration test. This “tools and techniques” section is presented in a reference format so you can locate a tool by its role in testing and obtain the information necessary to begin using the tool or find the information necessary to do so. A large collection of tools have been released by commercial and open-source programmers that identify vulnerabilities in networks, applications, and/or services and should be used as part of an assessment. While most of them may be identified by an intrusion detection system, they can usually find exposures on your network faster than manual methods. We provide detailed explanations of each tool, including its basic usage and where to get updates. You will find that some programs are described in greater depth than others. We spend more time on the tools that we find more helpful or that reveal the most information. For ease of use, we obtained demo or freeware software for many of the tools covered and included them on the CD-ROM available with this book. This software is intended to give you the opportunity to become familiar with some of the more popular tools and to see which work best for you. This section is designed to help you pick out the right hardware, operating systems, and software to make a testing tool kit.

The last section of this book (Chapters 17–23) moves toward advanced techniques and application testing. You should review this section once you have created and are comfortable with your own tool kit. This section details methods that can be used to evade intrusion detection systems and firewalls, control hosts on target networks remotely, and test Web servers. It also includes a discussion on denial-of-service attacks and a section on how to keep up with the current trends and latest developments in information security. This section contains a list of Web sites and e-mail lists that we used in our research, as well as information on long-term countermeasures to improve security. Finally, we include a brief discussion about future trends within the information technology arena and the possible risks that these trends may produce.

At the end of some chapters are case studies that deal with some of the issues and tools discussed. The case studies detail steps we have followed in real-world penetration-testing engagements to help illustrate how all the pieces of penetration testing fit together. The samples we selected include internal, external, and dial-up testing and reflect different operating systems, vulnerabilities, and exploits in an attempt to demonstrate as many of the techniques discussed in the book as possible. In each case we keep anonymous the name, industry type, and any other information that could be used to identify the parties involved.