Digital Forensics with Open Source Tools: Using Open Source Platform Tools for Performing Computer Forensics on Target.. Systems: Windows, Mac, Linux, Unix, etc [Paperback]

No dongle? No problem, says it all! Authors, Cory Altheide and Harlan Carvey, deliver a superb, field guide for digital forensic practitioners. This book is not a textbook on how to perform digital forensics, but a guide for the veteran or new forensic examiner to reference, to extend his/her analysis capabilities with open source tools. The authors bring their years of real world experience at practicing digital forensics, into a single publication.
Digital Forensics With Open Source Tools (DFWOST) begins by defining "free" vs. "open" and the digital forensic process, as well as the benefits of using open source tools. DFWOST quickly moves into setting up the examination workstation, that the examiner/analyst will use to perform the digital forensic examination; regardless, of the host operating system of your forensic machine.
While the book is not a textbook on how to perform a digital forensic examination, it does outline basic digital forensic concepts and terminology that the forensic examiner must comprehend to utilize the open source framework that the book mainly focuses upon, The Sleuth Kit.
From here, the book goes into depth with Windows, Linux, and Mac OS X operating systems and how to use open source tools to identify, parse, and "forensicate" the various system artifacts.
The book's final chapter focuses on automating forensic analysis and extending capabilities with open source tools Finally, the appendix is full of free, non-open source tools that you should become familiar with and integrate into your digital forensic toolkit. Remember, there are many ways to skin a cat! [Disclaimer: no kitteh's were harmed in compiling this book review :)]

Here's why I am giving this book a five star review:

1) Altheide and Carvey walk the reader through compiling a forensic examination workstation to utilize for a digital forensic investigation. It's full of tips, command line refreshers, and best practices delivered from experienced digital forensic professionals with perfect symmetry (i.e., "It is best to complete Y, to avoid Z").

2) In regards to symmetry, Altheide and Carvey do an awesome job of describing The Sleuth Kit Tools, breaking down the common TSK prefixes and each layer of TSK tools, which for new examiners can be task within itself. If you are new to TSK, DFWOST is the perfect companion.

3) Altheide and Carvey eliminate the barrier of just having OS specific forensic tools. Linux and Mac OS X users can now play in their own sandbox, using their own toys (Of course, Linux and Mac users knew this all along).

4) Chapter 8 on File Analysis is the longest chapter (41 pages in length), covering analysis of image files, audio and video files, archive files, and documents. This chapter breaks down a file's content and metadata. DFWOST puts file analysis into a practical and digestible format, that a new examiner should be able to apply immediately to a forensic investigation.

5) The book's length, based on the subject matter is spot on and not too cumbersome (255 pages including Appendix on Free, Non Open Tools). Just as Carvey done with Windows Registry Forensics (WRF), Digital Forensics With Open Source Tools (DFWOST) takes a sniper approach on the subject matter. Depending on what type of reader you are, you may knock it out in a single reading session; or, it may take several reading sessions, which will allow you to follow along, complete the examples, and exercises outlined in the book.

6) Lastly, the DFWOST print version that I purchased is signed by both authors. I was able to catch both authors at the Open Source Digital Forensics Conference last week in NoVa. Thank you gentlemen!

The book's content, length, and practical application make it a necessity for the digital forensic examiner's toolkit! Now, go forth and 'forensicate', DFWOST-style!

Let me start off by stating that I was provided a free review copy of this book by the authors and their publisher. I know both Cory Altheide and Harlan Carvey and I'm an admirer of their work in the field. If I hadn't been provided a review copy of the book, I would have purchased it on my own and reviewed it because of the trust I have in their abilities as researchers and writers. Part of me wishes I hadn't written that sentence because I know Harlan Carvey is working on another book and I probably just eliminated any possibility of getting a free review copy. Someday I'll learn, but today is clearly not that day.

Unsurprisingly, Cory and Harlan turned out a five star effort. The book does three things for the reader. First, it explains the purpose and use of a variety of open source digital forensic tools (as well as using an appendix to explain some free, but non-open source tools), it provides the reader with some foundational education on file system forensics (Windows, Apple, and Linux), and it explains selected important topics in digital forensics such as web browser forensics, shortcut files, and mail artifacts.

I had a bit of an internal debate regarding whether this book is something that an entry level person would be able to grasp in its entirety. Some of the concepts presented such as the more advanced file system forensic issues can be relatively complicated for a beginner. Ultimately, I think this complexity is a strength of the book in that it makes it a learning barometer of sorts. A good use of this book for a new forensic examiner would be to use it as a guide to determine which portions they already know and which portions are they find confusing. It's the confusing bits that should spur them onto further learning and research until they can come back to the book and understand the concepts that the authors are putting forth. This could have easily been a poorly written book whose explanations were impenetrable to someone new to the field, but it's well written enough that I think it serves as a good initial text for someone who is interested in the field.

This is also a useful book for experienced examiners who want to learn about the variety of open source tools that are available beyond the more expensive, but very popular closed source tools such as EnCase and FTK. While I find those tools to be very useful and beneficial, there has been quite a bit of development and innovation in the open source digital forensics community that can and should be leveraged by both new and experienced examiners.

Price is the potential concern that some might have with this book and that is understandable given the price. I have declined to purchase other interesting looking Syngress titles in the past because I didn't know enough about the authors or the books to justify the risk at the price they were offered. This book is relatively thin and I suspect there will be some concern about the price-to-page ratio. Had this book been written by authors unknown to me, I might very well have declined to purchase it if I hadn't been provided a review copy. However, in the case of this work, it's very much worth the price. This a very well done work that has been created by two respected practitioners and authors in the field and should be on the shelf of every person who is trying to break into the digital forensics field.

When I first saw the title for Digital Forensics with Open Source Tools (DFwOST) I thought to myself "Oh great, another mash up of Carrier's File System Forensic Analysis, Farmer & Venema's Forensic Discovery and the freely available Sleuthkit documentation." What I found, however, was a well-written, detailed and concise book detailing many of the most important, and freely available, open source tools that could be wielded in the name of system forensics and incident response. I've known both authors, Cory Altheide and Harlan Carvey, for quite some time and both are well known in forensic circles. The voice throughout the book is consistant and it's difficult to see where one author picks up and the other leaves off (well, when the conversation switches to RegRipper I'm fairly certain that Harlan is the predominate voice).

The first chapter outlines what constitutes a `free' vs. `open' tool, the various licenses and the benefits of standardizing on a mixed bag of non-commercial tools - hint, portability between jobs is a big bonus. Chapter 2, surprisingly, shows you how to build your own open source examination platform and walks the read through the installation and configuration of software, interpreters and other tools for both a Linux or Windows host. Chapters 3 through 7 provide overviews, tips and tricks on everything from disk and file system analysis techniques to searching for artifacts on Windows, Linux and OS X systems in addition to Internet specific artifacts like those left by browsers and mail clients. Chapter 8 gives a somewhat high-level view of file analysis concepts and provides some file-specifc format information for the investigator-on-the-go (who can really remember the various metadata available in a PDF file anyway?). Chapter 9 discussed the automation of analysis and some of the tools used to help extract common files, create timelines and work with graphical investigative environments like PyFLAG and the Digital Forensics Framework. Finally, the Appendix provides some high-level information on some complimentary, though not open, tools to help with the forensic process.

I can honestly say that I read this book in a matter of hours - not to mention in one sitting. My forensic knowledge and training did allow me to read through the book at a fairly decent pace but I think that even the most green of forensic analysts would walk away with a more detailed knowledge of the forensic process and the open source tools that could be used to undertake a forensic exercise. The book is not going to explain the file system and its intricacies at any great length but really, there are other books already written that do that. Also, the book won't show you how to do everything with the tools it mentions but it certainly will point the reader at some new tools that they may have never known about previously. It's safe to say that DFwOST is certainly no substitute for forensic training or experience but if you already have all of the standard forensics books on your bookshelf (you know the ones), you'd do well to save a slot for DFwOST as a quick reference for some of the newer tools not covered in those older tomes.