01
May
2012

Plaid CTF 2012 – Override

One look in this program and our whole understanding of how robots run has been shaken. Maybe you will have better luck than us.
Title: Override (300)
Category: Pirating

For this challenge we had to find a passphrase which was accepted by a 64-bit binary.
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01
May
2012

Plaid CTF 2012 – SIMD

After examining some code retrieved by our operative we are unsure whether it was written by an evil genius or a google employee. We will let you decide.
Title: SIMD (250)
Category: Pirating

For this challenge we had to reverse engineer the password from a 64-bit binary using SSE/AVX instructions.
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26
Jan
2012

MozillaCTF 2012 – Awesome Corp. Secured Ranges

This challenge entails reversing two (packed) Windows executables in order to retrieve an encrypted message. Once the algorithm and key generation method have been determined, a bruteforce search within a limited keyspace yields the valid key.

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26
Jan
2012

MozillaCTF 2012 – SecureFileLock

This very secure locking mechanism encloses files and only gives them to you when you know the passphrase. Find it and you will have the flag.

This challenge requires us to reverse engineer an executable and subsequently retrieve the decryption key for an embedded file.

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09
Jan
2012

GitS teaser 2012 – AL’s revenge

AL’s revenge was basically a crypto/math challenge with some file format puzzling at the start. The given file is an XZ archive which contains a program in LLVM bytecode. Since the unix ‘file’ utility knows about both these fileformats this wasn’t really hard to figure out. After that, the trick is to compile the LLVM bytecode to an ELF binary using the ‘llvmc’ tool, after which you can use your favorite disassembler/decompiler to reverse engineer the binary.

After having reversed the program and converting the important code to python it gets interesting!

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