What Is an Immutable Backup?

An immutable backup is a copy of your data that is locked at the storage layer against modification, deletion, or encryption for a set timeframe. Unlike regular backups governed by application-level policies, it cannot be overridden—even by administrators or ransomware variants.

How Immutability Works

Immutability relies on specific storage-layer mechanisms:

• WORM Storage: Write Once, Read Many physical hardware or software enforcement.
• S3 Object Lock: Cloud and on-premises software locking.
• Compliance Mode: An absolute lock that cannot be overridden or shortened by anyone.
• Governance Mode: A flexible lock that privileged storage administrators can bypass.

Immutable vs. Regular Backups

• Regular backups are vulnerable to compromised admin credentials and ransomware encryption.
• Immutable backups protect data from insider threats and malware by locking enforcement at the storage layer.
• Immutability does not replace a traditional strategy; it serves to upgrade your existing ransomware resistance.

Remaining Risks to Watch Out For

While ransomware cannot encrypt a properly locked file, vulnerabilities remain if you have:

• Short lock windows that expire before you detect a slow-moving attack.
• Compromised storage admin identities when utilising weaker Governance Mode settings.
• Data exfiltration, since immutability blocks deletion but does not stop unauthorised reading.

Air-Gapped vs. Immutable Backups

• Air-gapped backups are completely isolated from network connections, maximising security but slowing recovery.
• Immutable backups stay network-accessible to maximise operational restore speeds.
• The 3-2-1-1 rule combines both methods for complete, modern enterprise resilience.

The SaaS Shared Responsibility Gap

Major platforms like Microsoft 365, Salesforce, and Google Workspace do not offer native, customer-controlled immutable backups. Under the shared responsibility model, infrastructure availability belongs to the vendor, but data protection falls entirely on the customer. Third-party solutions are required to guard SaaS collaboration spaces against ransomware or accidental deletion.

If you want to find out how AvePoint Confidence Platform can help you with your data protection and governance, get in contact using the form below.