Have you tried feeding critical documents to a shredder? We’ve accidentally done this very thing. Shredder: shredder.exe Document remains: broken_flag.jpg We need our document back! See: http://hackyou.ctf.su/tasks/shredder Shredder is a Win32 binary that encrypt source file “flag.jpg” to “broken_flag.jpg”. The encryption is only some translations and swaps and can be […]
This challenge is about the control panel of the Southpark police department. (I wonder how many weird google searches I’m going to get on this post) You can choose an action and a victim. When you submit the form, it’s a simple AJAX call that will display “‘human’ was ‘action’” […]
RuCTFE is “classic” (these days it’s more like “old-skool”) Attack/Defense security game where multiple teams (150) compete to hack each other vulnerable services hosted in a VirtualBox machine provided by the CTF organizers at the beginning of the contest. Read more here about this great CTF and the network setup: […]
Challenge source code: #!/usr/bin/env python ”’ Running instructions. sockets are insecure. We do not implement any socket behaviour in this file. Please make this file +x and run with socat: socat TCP-LISTEN:45454,fork EXEC:./chal.py,pty,stderr Debugging: Just execute chal.py and play on terminal, no need to run socat Note: This […]
I don’t know why this was classified as “Web” during the CTF because it’s actually a Python TCPServer, nothing to do with Web. Anyways, the only hint we get for this challenge is “192.168.203.35:30050” When telneting to it, it does nothing, no banner. Sending a string will make it output […]
Don’t you love challenge with README ? We need your help, soldier! Your goal today is to help us obtain the access to Oscaderp Corp mainframe. Our intelligence has managed to install a keylogger and a formgrabber on some bad person’s work laptop. You don’t need his name to do […]
In this challenge we get a Win32 console binary which just display garbage when started. Reversing it with IDA, we see it connects to a TCP server. I had noticed previously that the file being transfered in the Epic Arc 200 challenge was an Erlang BEAM file (compiled erlang) This […]
Web challenge. We have the “source code” and we know the location of the flag: <!– can’t touch this: http://securerng.misteryou.ru/flag.txt.gz –> <!– can touch this: http://securerng.misteryou.ru/index.php.txt –> The web page is simple form to generate pseudo-random numbers. Here is the form: <form method=’POST’> Enter the […]
In this challenge we need to guess the secret key used by an encryption service running over UDP. We get the source of the server-side. The encryption algorithm uses a Sbox that is initialized with sequential numbers from 1 to 128: SALTED_SBOX = list(range(128)) Then the secret key is mixed […]
Exploit 500 is the final exploitation challenge for CSAW CTF. It looks like a game asking questions. You get 2 tries per question. .text:08048CF7 buffer1 = byte ptr -4B4h .text:08048CF7 buffer2 = byte ptr -438h .text:08048CF7 answer = […]