The year is 2050. It was a dark night in Fank Jr 2 the janitors house when the phone rang. There was a problem at the office and they needed him to come in and unlock the doors. Since it’s the future and all the doors are obviously digital, so…maybe you can give him a hand? (https://s3.amazonaws.com/mitre-stem-ctf/b2_2ee60279c734f27451f0cc17c2417601112fb70e.zip) His bed is really comfortable.

Reverse engineering keygen challenge.