Reverse Engineering and It’s Basic by Prasenjit Kanti Paul at null Kolkata Meet 16 September 2023

1. REVERSE
ENGINEERING BASICS
BY PRASENJIT KANTI PAL

2. WHOAMI
• Information Security Enthusiast
• Blessed to follow my passion as profession
• CTF Player
• Bug Bounty/CVE Hunter
• My Bengali Channel: RoyalBengalHacker

3. TARGET AUDIENCE
• If you are happy with automated hacking tools or scripts, may be you are not the
target audience
• If you are happy to be a script kiddies, may be you are not the target audience
• If you want to know “how deep the rabbit hole goes”, then this is the session for
you
• If you want to contribute with your R&D for our community, then this is the
session for you
• If you want to be an elite (31337), then this is the session for you

4. INTRO TO REVERSE ENGINEERING
• Engineering means a process to make a source code understandable to the
computer by compiling and linking to machine language
• Reverse Engineering means the techniques to get the source code or source like
code from the given binary or executable

5. DEBUGGER VS DISASSEMBLER VS DECOMPILER
• Debugger is a tool that
allows to examine the
state of a running program
• Example: OllyDBG,
WinDBG, Immunity
Debugger etc.
• Disassembler is a tool that
translates machine
language into assembly
language
• Example: OllyDBG, Ghidra,
IDA Pro etc.
• Decompiler is tool that
translates an executable
file to high-level source
code
• Example: JDGui, APKTools
etc.

6. PRE REQUISITE KNOWLEDGE
• Understanding of Operating System and its architecture
• Basic understanding of Programming language
• Basic understanding of Executables
• Basic Understanding of Assembly Languages
• Immense interest and curiosity

7. RE HELPS BELOW DOMAIN
• Malware Analysis
• Software Cracking
• Business Intelligence Gathering
• Exploit Development
• PWNing / Binary Exploitation (in CTF)
• Bug Tracing etc.

8. TOOLS (WINDOWS BASED)
• C/C++/Visual C++ : OllyDBG, Immunity Debugger, IDA Pro etc.
• DOTNET / C# : dnspy, dotnet reflector
• Java: JDGui
• APK: APKTool, dex2jar etc.
• PEiD, CFF Explorer, Hex Editors

9. HELLOWORLD.C
#include <stdio.h>
int main()
{
printf(“Hello World”);
return 0;
}

10. HELLOWORLD.EXE IN DEBUGGER

12. Crack An Application via 5 different techniques
• Using Conditional JMP
• Using Un Conditional JMP
• Using NOP
• Alter ZERO (Z) flag
• Change Address to successmsg

13. THANK YOU