MidNight Sun CTF 2025

27 de maio de 2025 · 424 palavras · 2 minutos · CTF Crypto

Two weeks ago (05/17), we (ELT) participated in MidNight Sun CTF 2025 Quals, a HackingForSoju’s annual CTF event to promote competition around the world. On this writeup, we will talk about a crypto chall, solved by Danilo (dant3) and Lucas (kyo). Oldchall The challenge had the following description ssh bionic@oldchall-wzmj3o9b.ctf.pro / Password: F33lOldY3t We posted the quals so much that this chall is straight from 2018. The initial step was to log in via ssh using the credentials provided, granting access to the challenge’s remote machine.

DEF CON Quals 2025

21 de maio de 2025 · 3208 palavras · 16 minutos · CTF Reversing Crypto

More than one month has past since DEF CON Quals, but we were so exhausted by it only now we managed to put together this set of write-ups. This year, several CTF-BR affiliated teams united to form pwn de queijo (a pun with pão de queijo). Together, we managed to achieve top17, the best position achieved by a Brazilian team until now. Let’s keep training to get qualified to the Finals next year :D

DamCTF 2025

12 de maio de 2025 · 3692 palavras · 18 minutos · CTF Reversing

This past weekend (05/09-05/11), we participated in DamCTF 2025, organized by the Oregon State University Security Club. On this writeup, first we will focus on two reverse engineering challenges: ‘Is it data or data?’ and ‘It’s data, not data’. They’re both related, in that they’re two different versions of a similar ‘game’, albeit with different rules and possible commands. You could say ’not data’ is a sequel to ‘or data?’, especially since the CTF admins recommended playing one after finishing the other.

WolvCTF 2025 — LockDown

15 de abril de 2025 · 3030 palavras · 15 minutos · CTF Reversing Hardware

It has been a few weeks since we played WolvCTF 2025, but I’ve been longing to write about LockDown, a simple but fun hardware reverse engineering challenge. The problem statement follows: I’m trying to use this adder, but I can’t figure out what password gets it to work. Can you figure it out? NOTE: to get the flag, convert the password bit-string into an ASCII string, with password[47] as the MSB and password[0] as the LSB.

LA CTF 2025

17 de fevereiro de 2025 · 2922 palavras · 14 minutos · CTF

O Epic Leet Team jogou o LA-CTF que ocorreu no final de semana do dia 08 até 09 de fevereiro. Os challenges de pwning foram resolvidos pelo professor orientador da frente de red team do projeto (com ocasionais ajudas de outros membros), e eu (Vini) embora com menos experiência, acompanhei a resolução dos desafios. Os challenges de crypto foram resolvidos pelo professor orientador, membros do ELT e a Laura, que no primeiro CTF dela resolveu um desafio e acompanhou as outras resoluções.