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

K-ecfs – kernel ECFS


In the previous chapter, we discussed the ECFS (short for Extended Core File Snapshot) technology. It is worth mentioning near the end of this chapter that I have worked out some code for a kernel-ecfs, which merges vmlinux and /proc/kcore into a kernel-ecfs file. The result is essentially a file similar to /proc/kcore, but one that also has section headers and symbols. In this way, an analyst can easily access any part of the kernel, LKMs, and kernel memory (such as the "vmalloc'd" memory). This code will eventually become publicly available.

A sneak peek of the kernel-ecfs file

Here, we are demonstrating how /proc/kcore has been snapshotted into a file called kcore.img and given a set of ELF section headers:

# ./kcore_ecfs kcore.img

# readelf -S kcore.img
here are 6 section headers, starting at offset 0x60404afc:

Section Headers:
  [Nr] Name              Type             Address           Offset
       Size              EntSize          Flags  Link  Info  Align
  ...