Azure Backup
Checks have been added to make sure only valid users can perform various operations. These include adding an extra layer of authentication. As part of adding an extra layer of authentication for critical operations, you're prompted to enter a security PIN before modifying online backups.
Authentication to perform critical operations
As part of adding an extra layer of authentication for critical operations, you're prompted to enter a security PIN when you perform Stop Protection with Delete data and Change Passphrase operations.
Reference:
https://docs.microsoft.com/en-us/azure/security/fundamentals/backup-plan-to-protect-against- ransomware
https://docs.microsoft.com/en-us/azure/backup/backup-azure-security-feature#prevent-attacks