Book Image

Learning Linux Binary Analysis

By : Ryan "elfmaster" O'Neill
Book Image

Learning Linux Binary Analysis

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

The importance of ptrace


In Linux, the ptrace(2) system call is the userland means of accessing a process address space. This means that someone can attach to a process that they own and modify, analyze, reverse, and debug it. Well-known debugging and analysis applications such as gdb, strace, and ltrace are ptrace assisted applications. The ptrace command is very useful for both reverse engineers and malware authors.

It gives a programmer the ability to attach to a process and modify the memory, which can include injecting code and modifying important data structures such as the Global Offset Table (GOT) for shared library redirection. In this section, we will cover the most commonly used features of ptrace, demonstrate memory infection from the attacker's side, and process analysis by writing a program to reconstruct a process image back into an executable. If you have never used ptrace, then you will see that you have been missing out on a lot of fun!