Protecting NonStop Backup from accidental/virus deletion possible?

For NonStop Backup to work, one needs to have a drive permanently available to write the backup to. However, the folders and files created by NonStop Backup are simply hidden files with no write protection and/or limited user rights to protect them from accidental deletion or a virus or hacker attack.
My question is therefore:
Is there a simple and reliable way to add this protection to NonStop Backup files and folders, maybe by adding certain NTFS folder permissions? Does the TrueImage Service run with elevated user rights?
Creating a Secure Zone on the drive used is somewhat unflexible, so I would like to avoid this solution if possible.
Also, I would be happy if TrueImage would do this automatically. Hiding files is not even a basic form of protection.