In this challenge at Insomni’hack CTF, you get an Android application (apk) to analyze. Had to look at that, obviously 😉. The challenge was solved as team work with 2 other team mates from Soudure au Beurre. Update April 20, 2024: PKCS7 and PKCS5 are basically the same. Corrected the explanation. Understanding the Android application In this challenge, you get an Android application. I decompile it to find a pretty simple application with 2 classes: MainActivity and Part1.

HackMe Hardware Challenges - Nullcon Berlin CTF 2024 The 6 challenges below use the same PCB. Update March 16, 2024: I forgot another fix we had to do for the first challenge + added solution to the last HackMe challenges. HackMe Fix the Board (5 solves) The PCB we are given does not work as such: the screen does not light up and the device does not boot correctly. We’ve got to repair it.

Advent of Code is a coding competition, with one new challenge per day during December. I started writing the core of my own solutions, then I realized this wouldn’t be very interesting because (1) my own code is often very naive compared to the best ones, (2) the article was starting to get very long. Instead, I will focus only on things I learned or already knew but experienced doing the challenges.