The Rev, or Reverse Engeneering category in CTF consists in reversing binaries, that is understanding their content and their functionality, to get the flag
Here are the writeups I wrote in this category:
Small Brainfuck reversing challenge @ Grehack2024 - WTBF
Difficulty: Medium Description: WTF if going on here? Author: Olivier For this Chall, we’re given a single text file: ++++++++++++++[>+++>+++>+++>++++++>+++<<<<<-] >>+++++>++++++>++++++++>>++++++++++++++++++ [>++++++>+++++>+++>++++>++++++++>+++++>++++++++ >+++>+++++++++++>+++++++>++>++++>++++++++>+++++++++++ +>++++++>++++++++++++>+++++++++++<<<<<<<<<<<<<<<<<-] >++++++++++++>++++++++++>>+++>++++>++++++++++++>+>+++++++++++++++>+> ++++++++++>+++++++++>+++>++++>++++++++++++++++>++++++>+>++++++++++++++++ [>>,[<+++>-]<+[<->-]<[]<] < [.<] This obviously looks like Brainfuck code. The first reaction is to convert to another language. Lots of converters can be found online, such as brainfuck to C converters. By doing so, it is easier to identify the program into three parts....