Reverse Engineering
Reverse engineering is understanding how something works when you don’t have the source code
It’s a core skill for malware analysis , vulnerability research , exploit development , and understanding proprietary protocols
Why Reverse Engineering Matters
- Malware analysis requires understanding what a binary does without source
- Vulnerability research needs to find bugs in compiled code
- Protocol reversing enables interoperability testing
- Competitor analysis (within legal bounds)
- Legacy code maintenance when source is unavailable
- Firmware analysis for IoT security testing
The RE Mindset
- Every observation is a hypothesis that needs verification
- Multiple analysis methods converge on truth
- Static analysis tells you what the code could do
- Dynamic analysis tells you what the code actually does
- Documentation is created not found
Analysis Approaches
Static Analysis - Examining code without executing it
- Disassembly (assembly instructions)
- Decompilation (higher-level representation)
- String extraction
- Import/export analysis
- Structure analysis
Dynamic Analysis - Examining code during execution
- Debugger stepping
- System call tracing
- Network monitoring
- Memory inspection
- API hooking
Common Targets
- Malware - Understand behavior, C2, persistence
- Binaries - Find vulnerabilities (buffer overflows, use-after-free)
- Firmware - Extract filesystems, find backdoors
- Mobile Apps - API endpoints, crypto schemes, hardcoded keys
- Protocols - Reverse engineer proprietary protocols
- Drivers - Kernel-level vulnerability research
Legal and Ethical Boundaries
- Only reverse engineer software you own or have permission to analyze
- Malware analysis in isolated environments only
- Vulnerability disclosure follows responsible disclosure process
- DMCA has anti-circumvention provisions (varies by jurisdiction)