Share how awesome the crack me was or where you struggle to finish it! Stay polite and do not spoil the solution/flag!
Author:
sally1337
Language:
C/C++
Upload:
10:17 AM 12/23/2025
Platform
Windows
Difficulty:
3.0
Quality:
4.0
Arch:
x86-64
Description
Nexus! (v2) - Upgraded CTF-Challenge for proffessionals. Goal - Obtain the correct license key for an arbitrary username and activate the program. Features - - 9 Anti-Debug Methods: PEB detection, NTDLL hooks, process scanning, hardware breakpoints, timing attack, virtualization detection, and more - 5-Layer Metamorphic Key Generator: Complex multi-stage cryptographic key derivation - Trap System: Honeypot messages designed to fool automated crackers - 100% Original Code: No commercial packers, pure C++ implementation. Author's Notes - This challenge demonstrates real-world protection techniques used in commercial software. The algorithm is deterministic and reproducible. All protection layers can be bypassed through legitimate reverse engineering techniques. Status - Fully workable. Verified solvable by me and my team. Hints (No Spoilers) Hint 1 - First Obstacle: The program has multiple layers of protection that will trigger when you try to debug it. These are intentional anti-analysis techniques. Common reverse engineering tools have ways to bypass or hide from these checks. Hint 2 - Key Generation: Once you get past the first obstacle, you'll find a function that generates keys. It's not a simple XOR or hash - it uses multiple transformation layers applied sequentially. The function name gives a hint about what it does. Hint 3 - Constants Are Visible**: The algorithm uses key material (constants) for each transformation layer. These constants are hardcoded in the binary in plaintext. No need to brute force them - just find them in the hex dump. Hint 4 - Start Simple: Test with a simple username like "test" first. Enter a dummy key (e.g., DEADBEEF-DEADBEEF-DEADBEEF-DEADBEEF) to see what the program tells you about partial matches. This feedback is useful. Hint 5 - Output Format Matters: The license key must be exactly 4 groups of 8 hexadecimal digits (uppercase or lowercase) separated by hyphens: `XXXXXXXX-XXXXXXXX-XXXXXXXX-XXXXXXXX`. Any deviation will fail validation.