Designing BSD Rootkits: an Introduction to Kernel Hacking Paperback – Apr 19 2007
|New from||Used from|
Customers Who Bought This Item Also Bought
No Kindle device required. Download one of the Free Kindle apps to start reading Kindle books on your smartphone, tablet, and computer.
Getting the download link through email is temporarily not available. Please check back later.
To get the free app, enter your mobile phone number.
About the Author
Tinkering with computers has always been a primary passion of author Joseph Kong. He is a self-taught programmer who dabbles in information security, operating system theory, reverse engineering, and vulnerability assessment. He has written for Phrack Magazine and was a system administrator for the City of Toronto.
Most Helpful Customer Reviews on Amazon.com (beta)
DBR covers much of the same sorts of material found in the earlier Rootkits: Subverting the Windows Kernel by Greg Hoglund and James Butler, except Kong's book is all about FreeBSD. I actually read the Windows text first, but found Kong's more direct language and examples easier than the Hoglund/Butler text. After reading DBR I have a stronger understanding of each of the main chapters' techniques, i.e., kernel modules, hooking, direct kernel object manipulation, kernel object hooking, run-time kernel memory patching, and detection mechanisms. I particularly liked the author showing his sample rootkit's effectiveness against Tripwire, simply to demonstrate his methods.
DBR follows another tenet of great books: it credits previous work. Several times in the text Kong says where he learned a technique or what code he's modifying to do his bidding. This should serve as an example to other technical authors. Kong also does not treat his subject matter as a dark art practiced by people in long black coats at Def Con. He is professional and mentions where certain techniques like run-time kernel memory patching are used by commercial operating systems for "hot patching," as happens with Windows.
I have nothing bad to say about this book, although to get the absolute full learning experience it helps to know C programming, some assembly, and FreeBSD kernel internals. The Design and Implementation of the FreeBSD Operating System by McKusick and Neville-Neil (another excellent book) is helpful preparatory reading. The fact that Kong provided all of his source code for download is also very much appreciated. Bravo! I look forward to your next book.
This enjoyable readable book gradually and very systematically evolves around hacking the kernel of a BSD system.
Chapter 1: Loadable Kernel Modules 22p.
Chapter 2: Hooking 13p.
Chapter 3: Direct Kernel Object Manipulation 20p.
Chapter 4: Kernel Object Hooking 4p.
Chapter 5: Run-Time Kernel Memory Patching 27p.
Chapter 6: Putting It All Together 26p.
Chapter 7: Detection 8p.
Its written in a style that allows also non-developers to grasp the main procedures and steps involved for modifying a systems kernel (assuming the attacker got access to a privileged system account).
Chapters 1 to 5 explain the several methods for modifying the kernel.
While the book is divided into 7 chapters, its most value really is the Chapters 6 which has many of those WoW effects included.
All or most technics described of chapters 1-5 will be used in chapter 6 for show casing how to circumvent an HIDS. Here is where all learned technics finally come all together.
So the reader dabbles with the author from an initial "simple" idea of bypassing an HIDS from one issue to the next. First the system call is hooked, so technically its kind of working, but then we realize that in order to make it perfect we need to hide the just created file (which contains the execution redirection routine). So the next obvious step is to hide the file so we dont leave a footprint on the system, just to realize that we need to hide the KLD (Dynamic Kernel Linker). So now everything is hidden but we forgot about the change of the /sbin directories access/ modification and change time, so we have to go after that too...
Its technically very interesting to learn how the author approaches the issues involved in order to avoid being detected by the HIDS or commands the user might use. That the author is technically on top of things is also shown f.e. by some info included in the book which is already referring to FreeBSD 7.
To get the most out of the book you ideally have programming knowledge of C, assembly etc. and debugging software systems. So I think its most valuable to system administrators, developers and security consultants.
The book is laid out quite well, with fantastic examples and explanations.
Unfortunately there are a few mistakes in the code examples due to some changes in the FreeBSD code (eg. the sys_ prefix was added to FreeBSD native syscalls )
Working through this book was fun and informative. You can download sources from [....]
The concepts apply equally well to Linux, of course, and I also realized that some of the areas explored come up in ordinary application work and especially in system troubleshooting, so this isn't entirely about subverting systems for evil purpose.