Today we come to you with an easy cryptography challenge. It requires basic knowledge about block cipher mode of operation and some files formats.
Two weeks ago you were asked to break the authentication system of a secret organization.
Today you are tasked by the same competing organization that hired you last time.
A file has been stolen from a manager of the secret organization it might contain the password to his email address.
Your employers need you to recover data from the encrypted file so they can access the email account and gather more informations.
The goal of this challenge is to recover some informations from the original file.