Ctf write ups
FCSC 2020 - Keykoolol (Reverse) - Write-up
This keygenme challenge was protected with virtual machine based obfuscation. Here is one solution based on Miasm dynamic symbolic execution (DSE) to disassemble the VM...
NorthSec 2019 - Doom (Reverse) - Write-up
Full solution of a multiple-steps reverse engineering challenge based on the game Doom. This write-up tears up the game apart with GZDoom builder and Z3.
NorthSec 2018 - Mars Analytica (Reverse) - Write-up
Mars Analytica was one of the remained unsolved challenge at the end of NorthSec 2018 CTF. Here is one solution using static analysis and Z3 to find the flag.
ECW 2017 - Red Diamond (Reverse) - Write-up
In this challenge, we have to analyze a MRuby interpreter and bytecode to find the flag. Both static and dynamic analysis methods are presented to resolve the challenge.