0CTF 2017 Quals – Zer0llvm

Talent Yang loves to customize his own obfuscator. Unfortunately, he lost his seed when he was watching Arsenal’s UEFA game. What a sad day! His team and his seed were lost together. To save him, could you help him to get back his seed? We can not save the game, but we may be able… Continue reading »

31 2010 CTF #3, #11, #14 (Most Epic Challenges :) writeup

Task #3 – Like skies that are so blue Sometime even pirates have a lazy sunday… download 0.  1. Open in your favorite image editor (ms paint) 2. Do a fill: 3. Md5 of the original file is the answer: 032c49411912397eea2a7d906dab5f7e Task #11 – Ecrime Business Cap’n Bill Greasepalms wants to start an ecrime business.… Continue reading »

31 2010 CTF #17 (Brainfuck) writeup

You found a backdoor on Captain Brainfuck’s webspace. Exploit it and read his secret file! The page only says ‘happy hacking’, so what would we be doing without its source… [source mirror] “Source” in fact is a zip archive with php code appended: PK < binary trash..> <?php @ob_clean();$z=zip_open(__FILE__); eval($f=zip_entry_read(zip_read($z),1000));@ob_end_flush();?> It simply reads itself (the… Continue reading »