Dark data is the unused information stored in your systems, often making up 55%...

https://lukaszaph075.almoheet-travel.com/what-is-intelligent-tiering-and-when-should-i-use-it

Dark data is the unused information stored in your systems, often making up 55% of all data. It can expose your organization to ransomware attacks and breach risks since it’s unmanaged and unmonitored