Data Backup is not enough to protect you from hackers. It is important to ensure your backups are encrypted and not accessible to just anyone that is logged into the computer. Hackers will infiltrate your system and spend some time on the system to determine where the backups reside and attempt to delete the backups. It doesn’t matter if it is a cloud backup or a drive attached to the computer. If the user they compromised has access to the information they will be able to delete all data before infecting your system with Ransomware.
If utilizing a third party cloud backup ensure it has a password and 2FA enabled as an additional preventive measure.
Keep in mind if the hacker gained access to the email account associated, they can reset the password and effectively work toward circumventing or turning off 2FA all together.
A good practice is to have multiple types of backup. Cloud Backup, Backup to disk, and ensure at least one of those is detached. Monitor all backup jobs to ensure the data isn’t tampered with, and be sure to test restores from time to time.