Dark data is information your business collects and stores but doesn’t use—up...

https://www.slideserve.com/aaron_ward92/why-does-dark-data-create-operational-drag-for-it-teams

Dark data is information your business collects and stores but doesn’t use—up to 55% of all data. This can increase your risk of ransomware attacks and data breaches since you’re unknowingly exposing unused files