Provided was a VirtualBox machine. When started, VirtualBox asked for a password to decrypt the virtual hard disk.
A quick search for cracking VirtualBox's disk encryption, lead to @sinfocol's VBOXDIE-cracker (coincidence?): https://github.com/sinfocol/vboxdie-cracker/

Feeded with the famous rockyou wordlist, the cracker found the password withing seconds: angel
For convenience reasons, I removed the VDI's password, since you never know what else you might have to do with the virtual disk ;)

Booting up the VM showed a simple text-based login screen. Guessing time, I guess. Trying username root with an empty password, gave no response. So, lets try root as password, too. Bingo, seems we have a shell. Listing file contents showed a single text file, with the content: ==9Z2ZhZnYj9lYnNGblB3Xsp3eChlU
Well, looks a reversed base64-encoded string. Reversing it again, it decoded to RXB{zl_pelcgb_cbvagf} Not quite the expected flag format, but close. Applying a ROT13 finally yielded our flag: EKO{my_crypto_points}



If that wasn't some great fun :D
~HomeSen