CTF Writeups
I do my best to write one for every task I solve, grouped by competition. Everyone starts somewhere, and these are meant to be the reference point I never had and couldn't find.
Capture the Flag is a cybersecurity competition. Every challenge hides a secret string, the flag, behind a weakness: a web app to break, a binary to reverse, a cipher to crack or a trail of public clues to follow. Find the flag, submit it, score points.
Each writeup here walks through one challenge, start to finish.
Playing in an upcoming CTF, or want company for one?Shoot me a message
Competitions
Oct 2026
Hidden Investigations CTF 2026
- Pwn 3
- Web 3
- Reversing 7
- Crypto 5
- Forensics 6
- Steganography 6
- Misc 6
- OSINT 2
- Hardware 2
- android 2
- blockchain 2
Oct 2026
FortID 2026
- Intro 6
- Pwn 6
- Web 5
- Reversing 5
- Crypto 5
- Misc 5
- OSINT 5
Mar 2026
Hackultet 2026
The third national CTF for university students, run by CERT.hr, CARNET and FER.
- Pwn 5
- Web 9
- Reversing 7
- Crypto 10
- Misc 2
Oct 2021
Hacknite 2.0
The second national CTF for Croatian high schools, run by CARNET's CERT.hr. Played for Elektrotehnička i prometna škola Osijek.
- Pwn 2
- Web 12
- Reversing 4
- Crypto 1
- Steganography 3
- Misc 4
- OSINT 2