Ransomware depends on encryption; there is a public key and a private key. Unless you have the private key, you cant readily get your data back. Maersk recovered from a devastating ransomware attack, but not with a backup. As we move from traditional domain controllers and on-premises computers to cloud services, take the time to review how you do backups and change your solutions accordingly. Most ransomware attacks come in from a user and whatever that user has access to is encrypted.”]
Source: https://www.csoonline.com/article/3395499/5-tips-for-better-backups-with-azure-backup-agent.html