HackTheBox Impossible Password Challenge

Explore the basics of cybersecurity in the Impossible Password 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/26

Description

Are you able to cheat me and get the flag?

Exploitation

XOR Decryption Analysis

Function Behavior

• Takes byte array as input
• XORs each byte with 9
• Stops when:
  • Encounters byte 9
  • Processes 20 bytes

Decoding Example

# Original hex string: A]Kr=9k0=0o0;k1?k81t
Original: 41 5d 4b 72 3d 39 6b 30 3d 30 6f 30 3b 6b 31 3f 6b 38 31 74
XOR 9:   48 54 42 7b 34 30 62 39 34 39 66 39 32 62 38 36 62 31 38 7d
ASCII:   H  T  B  {  4  0  b  9  4  9  f  9  2  b  8  6  b  1  8  }

Decoded Result HTB{40b949f92b86b18}

Summary

The Impossible Password Challenge on Hack The Box is an easy-level reverse engineering puzzle that introduces XOR decryption and basic binary analysis. Participants analyze a binary to identify a simple XOR-based obfuscation technique, where each byte is XORed with the key 9 to reveal the hidden flag. By decoding the obfuscated string, the challenge demonstrates how to reverse-engineer simple encryption schemes and extract meaningful data. Ideal for beginners, it provides hands-on experience with XOR decryption and binary forensics, offering a practical introduction to encryption reversal and data extraction.