PicoCTF 2019: whats-the-difference (Points 200)

Can you spot the difference? kitters cattos. They are also available at /problems/whats-the-difference… on the shell server In order to easily solve this challenge, I’ve used xxd and cut to generate an ascii hexdump of the images: Since I wanted to do a per character diff I wrote the following Python script: And finally run the script:

Bypassing ptrace calls with LD_PRELOAD on Linux

Hello, Here’s a quick article on how to bypass calls to ptrace when debugging a Linux executable. By calling ptrace with the PTRACE_TRACEME option, a process can detect if it’s being debugged and execute different instructions. This an effective anti-debugging technique. For example, take the following C program: If we execute the program from above we get Normal flow on … Read more