ZDbg is a professional-grade, interactive x86-64 Reverse Engineering simulator designed to help students and security researchers learn assembly code debugging, decompilation mapping, register mutations, and binary patching.

Developed by Zrnge, ZDbg runs entirely in the browser as a self-contained, single-file application with zero external dependencies.

• Synchronized C Decompiler: Real-time high-level pseudo-C code highlight mapping linked to active instruction pointers (RIP).
• Binary Opcode Patching: Right-click context menu in the disassembly view to patch instructions with NOP (0x90), unconditional jumps (JMP), invert conditional jumps (JE ↔ JNE), or revert patches.
• Sub-Register Inspector: Clickable registers displaying detailed bit ranges, sizing, decimal, hex, and ASCII mapping (demonstrating zero-extensions on 32-bit registers).
• Live Stack & Hex Dump: Little-Endian memory mapping, stack boundaries (RSP/RBP), and string decoding views.

ZDbg guides you through four distinct CrackMe levels of increasing difficulty:

1. Level 1: Basic XOR (Cryptography): Solve static bitwise XOR character checks. (Key: ZRNG)
2. Level 2: Rolling XOR (Rolling Cryptography): Reverse character checks dependent on previously popped values. (Key: GVfB)
3. Level 3: Algebraic Relations (Algebraic RE): Solve mathematical systems of equations (ADD, SUB, IMUL). (Key: UA@K)
4. Level 4: Anti-Debugging Bypass (Anti-Debugging): Bypass a simulated code-sensing scan that detects software breakpoints (0xCC / INT 3) by patching jump vectors. (Key: BYP!)

1. Clone or download this repository.
2. Double-click index.html to open it in any modern web browser.
3. Inject passcodes or apply binary patches to verify access codes.

Author: Zrnge