AppleDashPoni

"proprietary cryptography" there's your problem. Use open standards. Never roll your own. If you're using public, open standards like RSA, AES, PGP, and related things, nobody can crack them without the key, not even the government. Either you had no/useless encryption or had the keys stored somewhere, or had been keylogged or something similar. edit: Or were using an insecure password that was easy to guess.

This is misinformation.

Extremely simplified: Breaking standards like this requires successfully guessing a randomly-generated number that is so huge that trying enough possibilities to have even a 50% chance of guessing right would take every single computer on Earth, including supercomputers, working together, longer than the life of the universe. These numbers are chosen in such a way that it's mathematically proven to be impossible to decrypt data encrypted with these numbers (commonly called "keys") without knowing the key. https://en.wikipedia.org/wiki/RSA_(cryptosystem))

No "they" cannot. There is no "password reset". It's based on simple mathematics, not some third-party service that can be coerced into divulging keys. Here's a good starting point: https://en.wikipedia.org/wiki/RSA_(cryptosystem)) If that's too complex, do some Internet searches for "how RSA works" or "RSA explained".

Agreed that it was likely malware of some sort.