https://app.hackthebox.com/challenges/209

Description

Can you see me?

Exploitation

#!/usr/bin/env python3

def get_flag():
    v4 = 0x5517696626265E6D
    v5 = b"o&kUZ'ZUYUc)"
    v4_bytes = v4.to_bytes(8, 'little')
    combined = v4_bytes + v5
    result = ''
    for i in range(20):
        result += chr((combined[i] + 10) & 0xFF)
    return f"HTB{{{result}}}"

if __name__ == "__main__":
    print(get_flag())

Summary

You Cant C Me: reverse the validation logic, model the transform, and recover the accepted input.