About Us

/upb/hack is the CTF team at Paderborn University. While we started as a student group, we welcome anyone interested in security. Our main focus is competing in Capture The Flag challenges together, but we also look into other security topics outside of CTFs.

What are CTFs?

"Capture the Flag (CTF) in computer security is an exercise where participants conduct and defend against real-world security attacks. CTFs cover a wide range of disciplines including binary exploitation, reverse engineering, web security, cryptography, and forensics.

Contests typically follow one of two formats: Jeopardy! (teams solve challenges across various categories for points within a set timeframe) or Attack/Defense (teams defend their own vulnerable services while finding and exploiting vulnerabilities in opposing teams' services)."

Competitions & Events

We regularly play online CTFs throughout the year – check out our ranking and past events on our CTFtime profile.

Occasionally, we also travel together to on-site CTFs and security conferences. Recently, we attended:

  • Flag Wars: Attended with two teams in 2026, placing 3rd and 10th.
  • BruCON CTF (Belgium): Attended twice, placing 4th in 2025 and 2nd in 2023.
  • Deutsche Hackingmeisterschaft (DHM): Placed 9th in the 2024 finals.

Besides playing CTFs, we host our own beginner CTF each year for new students at Paderborn University.

Join us!

To check us out, join our Discord Server. We post upcoming meetings as Discord events, so keep an eye on the events tab. Feel free to say hi or ask questions!

Our meetings usually take place in Paderborn on Saturdays from 14:00 to ~22:00 whenever we’re playing a CTF. Just bring your laptop! We hold our meetings in German, but are always happy to switch to English.

Beginners are always welcome. With members of all backgrounds and skill levels, everyone learns from each other.

For hardware hacking and general tinkering, check out C3PB (Chaos Computer Club Paderborn). They run a local hackerspace with regular open evenings for anyone curious about technology.

Donations:

/upb/hack e.V.
IBAN: DE91472601218328783500
BIC: DGPBDE3MXXX

Wir sind ein eingetragener, gemeinnütziger Verein. Für eine Spendenquittung wenden Sie sich bitte an: spenden@upbhack.de

Unsere digitale Spendenquittung können Sie mit dem folgenden Zertifikat verifizieren: Zertifikat