Autorev

Ressource : https://www.youtube.com/watch?v=QkVzjn3z0iw

This challenge begins with a netcat connection informing us that we will receive 20 files and must reverse all of them within one second. The objective is therefore to automate the reverse engineering process. Angr immediately came to mind, as I knew it could be used for this type of task and had always wanted to try it.

The files are provided as long hexadecimal strings:

These raw binary bytes are actually ELF executables. Once disassembled, they turn out to be simple crackmes containing hardcoded passwords and prompting the user for a secret.

We begin by automating the extraction and reconstruction of the executable with Python

Using angr, we can symbolically execute the program to determine which input is required to reach a specific point in the binary.

Our goal is to reach puts("Correct!"), so we identify that address, as well as the failure path we want to avoid.

Once it works for the first reversing challenge, we wrap everything in a loop and test it against the others.