Solution by Berardinis:
After analyzing the program in IDA Pro and making several attempts with the correct values, we arrived at the following input: ``` welcome agent 1337, the evil group 0xL0CCEDC0DE has stolen 1337 BILLION dollars, you MUST get it back... for your first take you must hack into the admin account 0: enter username, 1: enter password, 2: login 0 enter ur username: AAAA 0: enter username, 1: enter password, 2: login 2 please try again as an admin! 0: enter username, 1: enter password, 2: login 1 enter ur password: root 0: enter username, 1: enter password, 2: login 1 enter ur password: IAMROOT1337 0: enter username, 1: enter password, 2: login 2 stage 1/2 of logging in done... stage 2/2 of logging in done... good job agent 1337! you must now use ur secret device to change the code to unlock the door! the current code is ABCD and you must change it! %.4919d%8$n .... YOU MADE IT agent 1337 you now have to get the money and escape wait is someone here? so mr 1337... you made it into our building... you want this money so bad right?? ok than, say my name and ill give it to you! what is my name?: stackpointer you did it... fine i guess you can have the money back AGENT 1337 YOU DID IT! ``` To determine the flag in the final stage, a Python script was written. Flag: `stackpointer`