About this video

• Video Title: How to Crack any Software
• Channel: Daniel Hirsch
• Speakers: Daniel Hirsch
• Duration: 00:30:21

Overview

This video explains the fundamental concept of software cracking by demonstrating how to patch a simple password-protected C program. The presenter walks through disassembling the compiled binary to identify the password comparison logic, then uses a hex editor to modify the jump instruction, effectively bypassing the password check and granting access regardless of the input.

Key takeaways

• Understanding Software Cracking: The video demystifies software cracking by showing it as the process of altering compiled binaries to bypass restrictions, such as password checks.
• Reverse Engineering Basics: It introduces tools like objdump for disassembling binaries to understand the underlying assembly code and identify key logic like string comparisons and conditional jumps.
• Patching Executables: The core technique demonstrated is modifying specific machine code instructions (opcodes) within a binary to change its behavior. In this case, changing a "jump if not equal" instruction to "jump if equal" (or vice-versa, depending on the logic flow) bypasses the password verification.
• Using Hex Editors: The video highlights the practical use of hex editors (like hexedit) to directly manipulate the raw binary data of an executable file, allowing for precise changes to opcodes.
• Circumventing Security: Cracking, as shown, allows users to gain access to software functionalities without needing the correct credentials or payment, by altering the program's execution flow.

The objdump -s command displays all sections of a binary file, showing the raw data in hexadecimal format. In contrast, objdump -d disassembles the executable sections of the binary, translating the machine code into human-readable assembly language instructions. While -s shows raw data at memory locations, -d focuses on the executable code and presents it as assembly.