HackTheBox Rebuilding Challenge

Explore the basics of cybersecurity in the Rebuilding Challenge on Hack The Box. This easy-level Challenge introduces encryption reversal and file handling concepts in a clear and accessible way, perfect for beginners.

https://app.hackthebox.com/challenges/352

Description

You arrive on a barren planet, searching for the hideout of a scientist involved in the Longhir resistance movement. You touch down at the mouth of a vast cavern, your sensors picking up strange noises far below. All around you, ancient machinery whirrs and spins as strange sigils appear and change on the walls. You can tell that this machine has been running since long before you arrived, and will continue long after you’re gone. Can you hope to understand its workings?

Exploitation

#!/usr/bin/env python3

encrypted = [
    41, 56, 43, 30, 6, 66, 5, 93, 7, 2, 49, 16, 81, 8, 90, 22,
    49, 66, 15, 51, 10, 85, 0, 0, 21, 30, 28, 6, 26, 67, 19, 89, 20, 0
]
key = "aliens"
password = ""
for i in range(32):
    decrypted_char = chr(encrypted[i] ^ ord(key[i % 6]))
    password += decrypted_char
print(f"Password: {password}" + "}")

Summary

The Rebuilding Challenge on Hack The Box is an easy-level reverse engineering puzzle that introduces participants to XOR decryption and key-based data reconstruction. The challenge involves decrypting a sequence of encrypted bytes using a repeating XOR key (aliens) to uncover a hidden password. By writing a Python script to perform the XOR operation between the encrypted data and the key, participants can reconstruct the original password and reveal the flag. This challenge serves as an excellent introduction to basic cryptographic techniques, such as XOR encryption and key-based decryption, making it ideal for beginners in cybersecurity. It provides a practical and hands-on way to explore how simple encryption schemes can be reversed and exploited, offering valuable insights into data manipulation and reverse engineering.