The Catch has ended. We know the winners.
All challenges are now open for playing.
Received write-ups were published and the awarded participants will be notified.

Through the organization of the annual Catch competition, we endorse the ideas of the Cyber Security Month in 2018, thus contributing to building a more secure Internet environment and cyberspace. The completion is organised by the CESNET Association in collaboration with Trend Micro.

Come and test your analytic and “hacker” skills in a capture the flag competition! You and your team can join and win amazing prizes and your chance to participate in the international Trend Micro CTF 2018 final in Japan!

Announcements (bugs, downtimes, etc.)

Basic information

The rewards

1st (on-line) Round

  1. Top 10 teams will be invited to the 2nd round (on-site).
  2. Other 10 teams (11th - 20th place) will be rewarded by The Catch hacker T-shirts.
  3. The fastest team to solve each challenge will be rewarded by small CESNET presents. If one team will be the fastest several times, that team will be awarded only once. To let everybody to play, next in order will be awarded.

2nd (on-site) Round

  1. The winner (team) has the right to be nominated to Trend Micro CTF 2018 finals in Japan.
  2. Top 3 teams will be rewarded by Tech Gadgets in total value of 72.000 CZK.
  3. All on-site contestants will be awarded with The Catch hacker hoodie.


As the knowledge is the best reward, we will publish all challenges. And still there would be a possibility to win The Catch hacker hoodie. Anyone except on-site participants will be asked to do a write-up (manual how to solve the challenges). All write-ups will be published and the best will be rewarded.

How to join the Competition

  1. Please read the Competition rules and/or FAQ
  2. Form a team (and select a team name).
    • If you have your own team, register it, see note 3).
    • If you have no team, find yourself teammates in slack platform.
  3. Once the registration is open, register the team (from October 26th and onwards), i.e. register a player account in the CTF platform (team name, e-mail and password need to be filled in).
  4. Try a practice challenges (to get acquainted with the environment).
  5. Once the competition is launched and the competition challenges are published, you can start solving the challenges:
    • Choose any of the challenges from the list. Challenges can be solved at a time, and they can be solved in whatever order.
    • Read the challenge assignment carefully.
    • Download the file(s) for the analysis or visit the stated URL.
    • Perform the analysis (when correctly performed, you should be able to discover the flag).
    • Insert the flag into the platform (to verify its correctness and acquire the points). The number of attempts is limited (the flag should be acquired not guessed).
    • We recommend inserting the results (the flags discovered) immediately after the challenge has been solved.