Hackers are going to encrypt or permanently delete your backups as a part of their ransomware attack. Ransomware has been so successful for them; they have been increasing the ransom to astronomical prices. Get prepared and lock hackers out of your backups, preventing them from destroying your only way to recover. Don't let a click by an end-user destroy your company. A fellow employee might provide a hacker access to the network by clicking on a phishing email, but the hacker will not be able to get to your backups, as long as secure them correctly.