Book Image

Antivirus Bypass Techniques

By : Nir Yehoshua, Uriel Kosayev
Book Image

Antivirus Bypass Techniques

By: Nir Yehoshua, Uriel Kosayev

Overview of this book

Antivirus software is built to detect, prevent, and remove malware from systems, but this does not guarantee the security of your antivirus solution as certain changes can trick the antivirus and pose a risk for users. This book will help you to gain a basic understanding of antivirus software and take you through a series of antivirus bypass techniques that will enable you to bypass antivirus solutions. The book starts by introducing you to the cybersecurity landscape, focusing on cyber threats, malware, and more. You will learn how to collect leads to research antivirus and explore the two common bypass approaches used by the authors. Once you’ve covered the essentials of antivirus research and bypassing, you'll get hands-on with bypassing antivirus software using obfuscation, encryption, packing, PowerShell, and more. Toward the end, the book covers security improvement recommendations, useful for both antivirus vendors as well as for developers to help strengthen the security and malware detection capabilities of antivirus software. By the end of this security book, you'll have a better understanding of antivirus software and be able to confidently bypass antivirus software.
Table of Contents (13 chapters)
1
Section 1: Know the Antivirus – the Basics Behind Your Security Solution
5
Section 2: Bypass the Antivirus – Practical Techniques to Evade Antivirus Software
9
Section 3: Using Bypass Techniques in the Real World

Buffer overflow

A buffer overflow (or overrun) is a very common and well-known attack vector that is mostly used to "overflow" vulnerable programs. This involves sending a large amount of data, which is handled without proper input validation, causing the program to fail in one of a number of ways. Once this vulnerability has been exploited, it can be used to inject malicious shellcode and take full control of the victim's device. Over the years, buffer-overflow vulnerabilities have also been exploited in the wild to bypass security mechanisms such as antivirus software, both through bypassing antivirus engines and through gaining full control of the target victim machine.

There are two types of buffer overflow vulnerabilities that can be exploited:

  • Stack-based buffer overflow
  • Heap-based buffer overflow

To keep things simple, we will focus on stack-based buffer overflow, since the goal of this book is to bypass antivirus software and not primarily...