Introduction

Welcome to Wireshark for Security Professionals. This was an exciting book for us to write. A combined effort of a few people with varied backgrounds-spanning information security, software development, and online virtual lab development and teaching-this book should appeal and relate to many people.

Wireshark is the tool for capturing and analyzing network traffic. Originally named Ethereal but changed in 2006, Wireshark is well established and respected among your peers. But you already knew that, or why would you invest your time and money in this book? What you're really here for is to delve into how Wireshark makes your job easier and your skills more effective.

Overview of the Book and Technology

This book hopes to meet three goals:

• Broaden the information security professional's skillset through Wireshark.
• Provide learning resources, including labs and exercises, to apply what you learn.
• Demonstrate how Wireshark helps with real-life scenarios through Lua scripting.

The book isn't only for reading; it's for doing. Any Wireshark book can show how wonderful Wireshark can be, but this book also gives you opportunities to practice the craft, hone your skills, and master the features Wireshark offers.

These opportunities come in a few forms. First, to apply what's in the text, you will practice in labs. You build the lab environment early on the book and put it to use throughout the chapters that follow. The second opportunity for practice is at the end of each chapter, save the last Lua scripting chapter. The end-of-chapter exercises largely build on the labs to challenge you again, but with far less hand-holding. Between the labs and exercises, your time spent with Wireshark ensures time spent reading is not forgotten.

The lab environment was created using containerization technology, resulting in a fairly lightweight virtual environment to be installed and run on your own system. The whole environment was designed specifically for you, the book reader, to practice the book's content. These labs were developed and are maintained by one of the authors, Jessey Bullock. The source code for the labs is available online. See Chapter 2 for specifics.

In short, this book is a hands-on, practice-oriented Wireshark guide created for you, the information security professional. The exercises will help you to keep you advancing your Wireshark expertise long after the last page.

How This Book Is Organized

The book is structured on the assumption that readers will start from the beginning and then work through the main content. The initial three chapters not only introduce the title application Wireshark but also the technology to be used for the labs, along with the basic concepts required of the reader. Readers already familiar with Wireshark should still work through the lab setup chapter, since future chapters depend on the work being done. These first three chapters are necessary to cover first, before putting the following chapters to use.

The majority of the book that follows is structured to discuss Wireshark in the context of information security. Whether capturing, analyzing, or confirming attacks, the book's main content and its labs are designed to most benefit information security professionals.

The final chapter is built around the scripting language Lua. Lua greatly increases Wireshark's flexability as an already powerful network analyzer. Initially, the Lua scripts were scattered thoughout chapters, but they were later combined into a single chapter all their own. It was also appreciated that not all readers are coders, so Lua scripts are better served through one go-to resource.

Here's a summary of the book's contents:

Chapter 1, "Introducing Wireshark," is best for the professional with little to no experience with Wireshark. The main goal is to help you avoid being overwhelmed, introduce the interface, and show how Wireshark can be your friend.

Chapter 2, "Setting Up the Lab," is not to be skipped. Starting with setting up a virtualized machine, this chapter then sets up the W4SP Lab, which you will use several times in upcoming chapters.

Chapter 3, "The Fundamentals," covers basic concepts and is divided into three parts: networking, information security, and packet analysis. The book assumes most readers might be familiar with at least one or two areas, but the chapter makes no assumptions.

Chapter 4, "Capturing Packets," discusses network captures, or the recording of network packets. We take a deep dive into how Wireshark captures, manipulates capture files, and interprets the packets. There's also a discussion around working with the variety of devices you encounter on a network.

Chapter 5, "Diagnosing Attacks," makes good use of the W4SP Lab, re-creating various attacks commonly seen in the real world. Man in the middle attacks, spoofing various services, denial of service attacks and more are all discussed.

Chapter 6, "Offensive Wireshark," also covers malicous traffic, but from the hacker's perspective. Wireshark and the W4SP Lab are again relied on to launch, debug, and understand exploits.

Chapter 7, "Decrypting TLS, Capturing USB, Keyloggers, and Network Graphing," is a mash-up of more activities as we leverage Wireshark. From decrypting SSL/TLS traffic to capturing USB traffic across multiple platforms, this chapter promises to demonstrate something you can use wherever you work or play.

Chapter 8, "Scripting with Lua," contains about 95% of the book's script content. It starts simple with scripting concepts and Lua setup, whether you're working on Windows or Linux. Scripts start with "Hello, World" but lead to packet counting and far more complex topics. Your scripts will both enhance the Wireshark graphic interface and run from the command line.

Who Should Read This Book

To claim this book is for security professionals might be specific enough to the general IT crowd. However, to most information security professionals, it's still too broad a category. Most of us specialize in some way or another, and identify ourselves by our role or current passion. Some examples include firewall administrator, network security engineer, malware analyst, and incident responder.

Wireshark is not limited to just one or two of those roles. The need for Wireshark can be found in roles such as penetration tester or ethical hacker-roles defined by being proactive and engaging. Additional roles like forensics analyst, vulnerability tester, and developer also benefit from being familiar with Wireshark. We'll show this through examples in the book.

Regarding expectations on the reader, the book makes no assumptions. Information security specializations vary enough so that someone with 15 years of experience in one field is likely a novice in other fields. Wireshark offers value for anyone in those fields, but it does expect a basic understanding of networking, security and how protocols work. Chapter 3 ensures we're all on the same page.

Any reader must be technically savy enough to install software or understand systems are networked. And since the book targets security professionals, we presume a fundamental level for information security. Still, as far as "fundamentals" go, Chapter 3 acts as a refresher for what's necessary around networking, information security, and packet and protocol analysis.

Further in the book, Wireshark is used in the context of various roles, but there's no experience requirement for grasping the content or making use of the labs. For example, the tools used in Chapter 6, "Offensive Wireshark" might be already familiar to the penetration tester, but the chapter assumes zero experience when instructing setup.

To sum up, we understand there is a wide spectrum of possible roles and experience levels. You might be employed in one of these roles and want to use Wireshark more. Or you might be getting ready to take on one of these roles, and recognize Wireshark as essential tool to use. In either case, this book is for you.

Tools You Will Need

The one tool required for this book is a system. Your system does not need to be especially powerful; at the most a few years old would be best. Your system will be first used in Chapter 2, "Setting Up the Lab." You first install and set up a virtualized machine. Then upon that virtual machine you will set up the labs.

Of course, this book can benefit those without a system, but a system is needed to perform the labs referenced throughout the book.

What's on the Website

The primary website needed for this book is the GitHub repository for the W4SP Lab code. The GitHub repo and its contents are explained further in Chapter 2, "Setting Up the Lab," where you first download and build the virtual lab environment. Then the Lab files are installed onto your virtual machine.

Other websites are cited throughout the book, mostly as pointers for additional resources. For example, some sites hold hundreds of network capture files that are available for analysis.

Summary

This is where the authors are at the edge of our seats, hoping you will leap into and enjoy the book, its materials, and the labs. A lot of thought and effort went into this book. Our only desire was to create...