Book Image

Learning Linux Binary Analysis

By : Ryan "elfmaster" O'Neill
5 (1)
Book Image

Learning Linux Binary Analysis

5 (1)
By: Ryan "elfmaster" O'Neill

Overview of this book

Learning Linux Binary Analysis is packed with knowledge and code that will teach you the inner workings of the ELF format, and the methods used by hackers and security analysts for virus analysis, binary patching, software protection and more. This book will start by taking you through UNIX/Linux object utilities, and will move on to teaching you all about the ELF specimen. You will learn about process tracing, and will explore the different types of Linux and UNIX viruses, and how you can make use of ELF Virus Technology to deal with them. The latter half of the book discusses the usage of Kprobe instrumentation for kernel hacking, code patching, and debugging. You will discover how to detect and disinfect kernel-mode rootkits, and move on to analyze static code. Finally, you will be walked through complex userspace memory infection analysis. This book will lead you into territory that is uncharted even by some experts; right into the world of the computer hacker.
Table of Contents (17 chapters)
Learning Linux Binary Analysis
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

stock vmlinux has no symbols


Unless you have compiled your own kernel, you will not have a readily accessible vmlinux, which is an ELF executable. Instead, you will have a compressed kernel in /boot, usually named vmlinuz-<kernel_version>. This compressed kernel image can be decompressed, but the result is a kernel executable that has no symbol table. This poses a problem for forensics analysts or kernel debugging with GDB. The solution for most people in this case is to hope that their Linux distribution has a special package with their kernel version having debug symbols. If so, then they can download a copy of their kernel that has symbols from the distribution repository. In many cases, however, this is not possible, or not convenient for one reason or another. Nonetheless, this problem can be remedied with a custom utility that I designed and released in 2014. This tool is called kdress, because it dresses the kernel symbol table.

Actually, it is named after an old tool by Michael...