Azure immutable backups: Protecting your data from ransomware and insider threats

Data protection is a critical aspect of designing any IT system, in the cloud or on-premise. Organisations must take proactive steps to safeguard their backups against threats. 

One of the most effective ways to ensure backup integrity is by using immutable backups—a solution that prevents data from being altered or deleted within a specified retention period. 

Whether defending against ransomware, meeting regulatory compliance, or mitigating insider threats, Azure’s immutable backup vaults provide an extra layer of security. 

In this blog, we’ll explore why immutable backups are essential, how they work in Azure, and what operational considerations to keep in mind.

The importance of immutable backups in cloud security

There are a number of reasons that immutable backups can help an organisation and are worth considering.

Ransomware Protection

Immutable backups are a defence mechanism against ransomware attacks, which often involve deleting data or encrypting data to extort victims.   With Azure’s write-once, read-many (WORM) storage it enables you to ensure backup data cannot be altered or erased within the set retention period. 

Alongside general security and identity best practices this helps to ensure that even if attackers infiltrate your environment and gain elevated privileges, they cannot compromise the integrity of immutable backups. 

Regulatory Compliance

There are industries that require strict regulations around preserving data in its original form for a long period of time.  Azure immutable backups can help meet those requirements. 

Insider Threats

There is also the threat of insider threats, which could be malicious or accidental. Employees with access to systems may attempt to modify, delete or misuse backup data, either intentionally or through negligence.  

Azure immutable backups can provide additional protection by locking data from any changes during the retention period. 

Immutable backup vaults in Azure

It’s key to remember that enabling immutability for an Azure vault is a reversible operation.  However, you can enable the immutability to be enabled and locked, which is irreversible.

Enabling immutable vaults

To enable immutability you can enable it by following these steps:

1. Navigate to the desired vault in the Azure portal
2. Under Settings, select Properties, then Immutable vault and then click on Settings

3. Check the box to enable immutability for the vault.  This setting is reversible. 
4. To make immutability permanent, lock the setting.  This ensures backups use WORM storage, once this setting is locked immutability cannot be disabled.

It’s important that you test and validate your configurations before you lock the immutability setting to ensure it aligns with your requirements. As locking the setting can’t be undone. 

Operational restrictions

When you enable immutable vaults it imposes restrictions.  You can’t decrease retention periods for recovery points, but you can increase retention periods. These controls are there to prevent accidental or unauthorised deletion of backup data while still allowing updates that enhance data preservation. 

Immutable Vault Availability

Immutable vault functionality is widely available, however the use of WORM storage for immutable vaults in locked state is currently in General Availability (GA) for Recovery Services Vaults in the following regions only; Australia Central 2, Switzerland West, South Africa West, Korea Central, Germany North, Korea South, Spain Central.

And it’s worth noting that WORM storage for immutable vaults in locked state is applicable for the following workloads: Azure Virtual machines (VM), SQL in Azure VM,, SAP HANA in Azure VM, Azure Backup Server, Azure Backup Agent, Data Protection Manager (DPM).

So it’s key when you are looking at using the locked state for immutable vaults, you are aware of regional availability as well as which workloads it will work for. 

Conclusion

Implementing immutable backups is a powerful strategy for enhancing data security and resilience in the cloud. 

By leveraging Azure’s immutable vaults and WORM storage, organisations can protect their critical backup data from ransomware attacks, insider threats, and accidental deletions while ensuring compliance with industry regulations. 

However, it’s crucial to carefully assess your requirements, validate configurations, and consider operational restrictions before enabling and locking immutability. With the right approach, immutable backups can be a cornerstone of your cloud security strategy, providing long-term data integrity and peace of mind.