Reverse Engineering

Reverse engineering is the process of analyzing compiled binaries to understand their functionality without access to source code. This skill is essential for malware analysis, vulnerability research, exploit development, and software security auditing.

Legal Considerations

Reverse engineering may violate EULAs, copyright law, or anti-circumvention provisions (DMCA Section 1201 in the US). Always verify legal standing before reversing proprietary software.

RE Methodology

Static Analysis

Examining code without execution:

• Disassembly (machine code → assembly)
• Decompilation (assembly → pseudo-C)
• String extraction and cross-references
• Import/export table analysis
• Control flow graph analysis

Dynamic Analysis

Observing behavior during execution:

• Debugging with breakpoints
• API call monitoring
• Memory inspection and modification
• Code tracing and stepping
• Runtime decryption/unpacking

Essential RE Tools

Disassemblers

• IDA Pro (gold standard)
• Ghidra (NSA, free)
• Binary Ninja
• Radare2 / Cutter

Debuggers

• x64dbg (Windows)
• GDB + pwndbg (Linux)
• WinDbg (kernel)
• LLDB (macOS)

Decompilers

• Ghidra Decompiler
• IDA Hex-Rays
• dnSpy (.NET)
• JD-GUI (Java)

Common RE Use Cases

Malware Analysis: Understanding how malware works, extracting C2 domains and encryption keys
Vulnerability Research: Finding bugs in closed-source software for security research
Exploit Development: Understanding target binaries to craft reliable exploits
License Bypass: Cracking software protection (educational purposes only)
Protocol RE: Reverse engineering proprietary network protocols
Firmware Analysis: Extracting and analyzing embedded device firmware