Book Image

Mastering Malware Analysis

By : Alexey Kleymenov, Amr Thabet
Book Image

Mastering Malware Analysis

By: Alexey Kleymenov, Amr Thabet

Overview of this book

With the ever-growing proliferation of technology, the risk of encountering malicious code or malware has also increased. Malware analysis has become one of the most trending topics in businesses in recent years due to multiple prominent ransomware attacks. Mastering Malware Analysis explains the universal patterns behind different malicious software types and how to analyze them using a variety of approaches. You will learn how to examine malware code and determine the damage it can possibly cause to your systems to ensure that it won't propagate any further. Moving forward, you will cover all aspects of malware analysis for the Windows platform in detail. Next, you will get to grips with obfuscation and anti-disassembly, anti-debugging, as well as anti-virtual machine techniques. This book will help you deal with modern cross-platform malware. Throughout the course of this book, you will explore real-world examples of static and dynamic malware analysis, unpacking and decrypting, and rootkit detection. Finally, this book will help you strengthen your defenses and prevent malware breaches for IoT devices and mobile platforms. By the end of this book, you will have learned to effectively analyze, investigate, and build innovative solutions to handle any malware incidents.
Table of Contents (18 chapters)
Free Chapter
1
Section 1: Fundamental Theory
3
Section 2: Diving Deep into Windows Malware
5
Unpacking, Decryption, and Deobfuscation
9
Section 3: Examining Cross-Platform Malware
13
Section 4: Looking into IoT and Other Platforms

Key-scheduling algorithm

The key-scheduling part of the algorithm basically creates an array of 256 bytes from the secret key, which is just another, bigger version of the key. This array will be the key that is used to encrypt and decrypt the data afterwards. This part consists of the following two parts:

  • It creates an array with values from 0 to 256 sequentially:
for i from 0 to 255
S[i] := i
endfor
  • It swaps bytes based on the key—this generates an index number, j, based on the secret key:
for i from 0 to 255
j := (j + S[i] + key[i mod keylength]) mod 256
swap values of S[i] and S[j]
endfor

Once this initiation part for the key is done, the decryption algorithm starts. In most cases, the KSA part is written in a separate function that takes only the secret key as an argument, without the data that needs to be encrypted or decrypted.