3rd December 2021
Write-up Advent of CTF challenge 1

Write-Up Advent of CTF 1


The NOVI University Of Applied Sciences is offering an Advent CTF challenge for December 2020. The CTF is created by our community member of the Hackdewereld.nl and Chief Lecturer for Cyber Security at the NOVI University, Arjen Wiersma. If you want to participate in these CTF challenges, you can create an account on the website https://www.adventofctf.com/.

Challenge 1

  • Description: All starts should be easy.
  • Points: 100

This challenge has this URL: https://01.adventofctf.com/. So, I visited this URL.

Advent for CTF Challenge 1 website

Well, do I have to guess the password? Let’s first check the source code of this website. And, it looks like the one base64 uncoded flag is present in the source code. This looks a lot like challenge 0 🙂

Advent for CTF Challenge 1 flag
Source code with encoded flag


After decoding this Base64 encoded string, I got the password to log on. So, no password guessing, no Python script creation to password spray, just reading the source code. Sometimes it’s as simple as it seems

~$ echo "YWR2ZW50X29mX2N0Zl9pc19oZXJl" | base64 -d 

After logging in on the website as Santa, I got the flag.

Advent for CTF challenge 1 flag
Advent for CTF challenge 1 flag

Thanks for reading!


I'm a cybersecurity enthusiast! I'm working as an IT Security Engineer for a company in The Netherlands. I love writing scripts and doing research and pentesting. As a big fan of Hack The Box, I share my write-ups on this blog. I'm blogging because I like to summarize my thoughts and share them with you.

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