founded a company to develop it, raised some startup money, got the patents... and sold it all to a much bigger company in 2005. The technology is called continuous snapshot remote backup with deduplication ( yes, I invented dedupe ). And the consumer facing software was called time traveler. With it in operation you could fork the timeline of your storage system at any point in time in the past and create a virtual storage system that is that point in time in the past, before malware encrypts all of your data. Meaning EVERY write to your storage is not an overwrite but a write to a unused bit of storage... and you can set how long or how much data these time forks are available ( weeks or months or even years, but be aware that the longer the duration, the more total storage you will need to rent or buy - I leased storage to my customers buy putting it in large servers at ISPs... something we now call "cloud" storage ). Anyway, once you detect the malware encryption event... you pick a time just before it and set the virtual time line to that point... and start using your storage again - after doing the appropriate updates to you cyber security to prevent a re-infection. The demos were very effective in 2002 and 2003... but the dotcom bust caused my funding to dry up so I sold the company, made money for myself and my co-founder and all my investors... and the company that bought me turned out to be a patent troll... and made like $100M filing lawsuits against other de-duplication companies for patent infringement.
Sigh.
The * is that of course it would not prevent ALL ransomware attacks... it didn't prevent someone from, for example, stealing the private information you have and using it against you or your customers (ssn, date of birth, legal names, etc), and for very sophisticated hackers, you could potentially find the cloud storage and encrypt that too... but that would be very difficult for most hackers.