Intro
I discovered Advent Of OSINT in early December 2025, through a Reddit post on r/adventofcode about alternatives tech-related Advent Calendar.
I love OSINT since a really long time, but never really took the time to fully go into it. I thought it would be a good opportunity to try what I could do, learn new tech, new tools, and improve!
In the end, those specific challenges were really approachable, and even a green feet could manage to complete some. A lot of days were research-oriented (Google Search), a lot of image (Reverse Image Search), and some geographical too. At the end of the day, no crazy special tool were required, allowing anybody to try and have fun! I even brought some friends to help me on some days, and they acquired a taste for it too!
What started being a fun time-killer ended being a real competition for the leaderboard, and that was a lot of fun!
Big thanks to OSINT4Fun and all OSINT-related communities for creating, writing and hosting this event!
Structure
I used this event as a motivation to finally build my blog/writeup website.
Each day is divided in its sub-post of this post, allowing a better readability.
For each day/challenge, you’ll find at the bottom of the sub-post a box that gives information about the current challenge:
- The Direct link to the challenge ;
- The Difficulty of the challenge (defined by the authors of the challenge) ;
- The Helpers are the people that helped me for this challenge (if any) ;
- The Leaderboard rank (challenge completion order) I’ve reached for this challenge ;
- The Flag(s) (answer(s)) for these challenge (multiple flags for challenges with multiple parts) ;
- The challenge description, with attachment, if any (image, sound).
Question
The questions are inside those fancy boxes, in bold.
Answer
The answers are inside those fancy boxes, closed by default to avoid spoilers.
Alternative
These boxes are for alternative methodology or tools that I originaly though of, easier or harder, it depends!
Closed by default to avoid spoilers.
Challenge error
If you pay close attention, you may find one box like these, indicating an error in the challenge statement or attachment, that I noticed and reported to the authors. It was fixed since, but you’ll get some extra interesting details about proof of the error!
Closed by default because no longer relevant after the fix.