This weekend, Kalmarunionen set out to win Hack.lu CTF — a great competition that’s been running for 15 years, hosted by the German team fluxfingers from Ruhr University Bochum.

After finishing 2nd place in both 2023 and 2024, we were determined not to let history repeat itself. We started strong, held the top …

Fourth time’s the charm!

After years of competing and qualifying through Google CTF — where the top 8 teams earn a place in the Google Hackceler8 finals — Kalmarunionen took home the Hackceler8 2025 trophy and cash prize in Mexico City!

This year, a dedicated group went all in on preparation for the finals — and …

It came down to the wire. Other amazing teams like Maple Bacon, Shellphish, and especially BunkyoWesterns and r3kapig pushed us right to the last minute. That pressure is exactly why we are playing the hardest CTFs in the world.

This is our fourth ASIS CTF win, and it’s a reminder that the top is never …

Our team went all in at Google CTF 2025 and crossed the finish line in second place, securing 37.000 DKK, and for the fourth time - a ticket to the Google Hackceler8 Finals, this year held in Mexico City.

We were proud that the Minister for Digital Affairs (Digitaliseringsministeriet), Caroline Stage Olsen, accepted …

This weekend, Kalmarunionen gathered physically for another meetup at Eupry in Copenhagen for an intense and fun-filled hacking meetup - joined by several of our teammates chiming in remotely! 🧠⚡

While we were initially prepping for two bigger CTFs that unfortunately got postponed, we quickly adapted and dove headfirst …

🎉 Kalmarunionen is back with another electrifying edition of #KalmarCTF! 🎉

Last year was a blast, and we’re dialing it up yet again. Mark your calendars for March 7th - March 9th, 2025 – 48 hours of relentless hacking, mind-bending challenges, and a battle for ultimate CTF glory. …

🎉 We Did It! 🎉

Kalmarunionen is now officially the #1 competitive hacking team in the world! 🏆

✨ The Road to #1

It’s been an incredible journey since we started in 2020, climbing our way up the global rankings on CTFtime.org:

• 2020: 66th place
• 2021: 15th place
• 2022: 10th place
• 2023: 3rd place
• 2024: 1st place 🚀

So many …

We just won the Chaos Communication Congress (38C3) HXP CTF in Hamburg - ending the year in style and securing our qualification for DEF CON Finals 2025!

The Chaos Communication Congress (38C3) is the 38th installment of this renowned conference, where 14,000 security enthusiasts gather every year between Christmas and …

This weekend, we had our last big meetup in Copenhagen for the year, and it was a blast! 🎉

We had a fantastic time participating in the SECCON CTF, where we secured a top 10 placement. The challenges were engaging, and it was great to see so many new players testing out for the team. There’s a lot of promising …

Prioritizing and securing your OT infrastructure isn’t just a good idea—it’s essential for protecting our critical systems. Here’s an example of why:

It’s Cybersecurity month, and of course, Kalmarunionen want to showcase our talent! Although Operational Technology Security isn’t …