# Reverse Engineering

<table><thead><tr><th width="174" align="center">Challenge</th><th width="177" align="center">Event</th><th width="278" align="center">Tags</th><th align="center">Difficulty</th></tr></thead><tbody><tr><td align="center">Remote C4</td><td align="center">APU iCTF 2023</td><td align="center"><em>Rivest Cipher 4 (RC4), Middle-Square Method</em></td><td align="center">★★☆☆☆</td></tr><tr><td align="center">Grape</td><td align="center">ABOH 2023</td><td align="center"><em>Wine, Code Checksum</em></td><td align="center">★☆☆☆☆</td></tr><tr><td align="center">MetalPipe</td><td align="center">ABOH 2023</td><td align="center"><em>Race Condition</em></td><td align="center">★★☆☆☆</td></tr><tr><td align="center">Vacine</td><td align="center">SiberSiaga 2023 (Finals)</td><td align="center"><em>Manual Unpacking, Process Injection</em></td><td align="center">★★☆☆☆</td></tr><tr><td align="center">Malbot</td><td align="center">SiberSiaga 2023 (Finals)</td><td align="center"><em>Telegram-as-a-C2</em></td><td align="center">★☆☆☆☆</td></tr><tr><td align="center">Packed</td><td align="center">SiberSiaga 2023 (Finals)</td><td align="center"><em>Manual Unpacking, Module Breakpoints</em></td><td align="center">★★★☆☆</td></tr><tr><td align="center">Obstacles</td><td align="center">SiberSiaga 2023 (Finals)</td><td align="center"><em>Anti-Debugging, Binary Patching</em></td><td align="center">★☆☆☆☆</td></tr><tr><td align="center">Maze</td><td align="center">ACS 2023 (Qualifiers)</td><td align="center"><em>Binary Patching, GDB Scripting</em></td><td align="center">★★☆☆☆</td></tr><tr><td align="center">rustarm</td><td align="center">ACS 2023 (Qualifiers)</td><td align="center"><em>Rust, XOR</em></td><td align="center">★★☆☆☆</td></tr><tr><td align="center">expr</td><td align="center">ACS 2023 (Qualifiers)</td><td align="center"><em>Angr, Multi-threaded</em></td><td align="center">★★★☆☆</td></tr><tr><td align="center">babyrev</td><td align="center">ACS 2023 (Finals)</td><td align="center"><em>Angr, Symbolic Memory, Library Calls</em></td><td align="center">★★☆☆☆</td></tr><tr><td align="center">Licrackense Pt I </td><td align="center">ACS 2023 (Finals)</td><td align="center"><em>z3, Angr</em></td><td align="center">★★☆☆☆</td></tr><tr><td align="center">Defeat the boss!</td><td align="center">Wargames.MY 2023</td><td align="center"><em>Game Hacking</em></td><td align="center">★☆☆☆☆</td></tr><tr><td align="center">World 3</td><td align="center">Wargames.MY 2024</td><td align="center"><em>Game Hacking</em></td><td align="center">★☆☆☆☆</td></tr><tr><td align="center">EndlessCycle</td><td align="center">HTB Cyber Apocalypse 2025</td><td align="center"><em>Self-decrypting Shellcode</em></td><td align="center">★★☆☆☆</td></tr></tbody></table>