Challenge

Welcome to this first writeup dedicated to BreizhCTF 2026! It took place on May 22-23, 2026 in Rennes. I was lucky enough to take part in France's biggest CTF with 5 of my friends. As always, I focused on the OSINT challenges of this CTF.

This first challenge involves finding the first and last name of a celebrity linked to the BZH Mafia.

Methodology

We can spot the link present in the image: pastebin.com/ZKn19pqk

The Pastebin note is however password-protected:

In the note, there's a mention of a password: "the password is the name of the mascot animal of the hotel attached to the building in the photo [...]"

Then, looking at the photo on the right, a simple reverse image search identifies the building:

It's the Aoyama Technical College, in Tokyo (Japan).

To find the name of the hotel's mascot animal, a Google Maps search finds the hotel facing the Aoyama Technical College:

It's the Koala Inn Shibuya Sakuragaoka, so the password is very likely "Koala".

Back on Pastebin, the password "Koala" is indeed valid!

This note gives us various pieces of information, but the one that stands out the most to me is a link to a YouTube account: youtube.com/@BzhMafia56

The account hasn't published anything, but a playlist is public:

It contains "Back In Time" from the movie "Back To The Future":

Following this discovery, my reflex is to look for archives of this channel on the Wayback Machine:

On April 27, 2026, the account published a Short on its page:

Since the Wayback Machine can't archive YouTube videos, I copy the Short's link to paste it in a new tab, and we land on the unlisted flag video:

In the video, I recognize Sylvain Durif, aka the Cosmic Christ, the Great Monarch, the Messiah, the King of the Cosmos, Pope Peter, Merlin the Enchanter, the Green Man (or Sylvanus, Oriana), the President of peaceful planetary and cosmic governance Elvita.

Small point of pride, I was the first to solve this challenge! So I got to play a song of my choice in front of more than 600 people.

Flag