Passwords - A Cracking Christmas | Advent of Cyber 2025 - Day 9

This guide contains the answer and steps necessary to get to them for the Passwords - A Cracking Christmas room.

Table of contents

• Attacks Against Encrypted Files

Attacks Against Encrypted Files

1. What is the flag inside the encrypted PDF?

   We can try obtaining the password for the PDF using pdfcrack.

   cmd

   Copy

   pdfcrack -f flag.pdf -w /usr/share/wordlists/rockyou.txt
   

   

   We can see that pdfcrack managed to get a password. Now we can get our flag by unlocking the pdf file with this key.

   

   Click for answer

   THM{Cr4ck1ng_PDFs_1s_34$y}

2. What is the flag inside the encrypted zip file?

   Since fcrackzip is not installed on our machine, we will use john.

   cmd

   Copy

   zip2john flag.zip > ziphash.txt
   john --wordlist=/usr/share/wordlists/rockyou.txt ziphash.txt
   

   

   We can see it managed to obtain the used password. Now we can extract the file using this password and get our second flag.

   

   Click for answer

   THM{Cr4ck1n6_z1p$_1s_34$yyyy}

3. For those who want another challenge, have a look around the VM to get access to the key for Side Quest 2! Accessible through our Side Quest Hub!

   Click for answer

4. If you enjoyed this task, feel free to check out the Password Attacks room.