Immutable backup or storage means that your data is fixed, cannot be altered, and can never be deleted. Immutable backups are essential for any company that needs to ensure they have a copy of their data that is always recoverable and protected from unwanted and accidental incidents. Once you store an immutable backup, it cannot be modified or changed. This is especially important in the case of malware or ransomware. If your backup is immutable, it remains protected from new ransomware infections.
But in practice, many backups marketed as ‘immutable’ aren’t truly immutable, and here’s why they fail:
They rely on software, not true storage locks: Some backup tools claim their backups are “immutable,” but this is mostly just software tricks and access controls. If someone gains the right credentials or access to the server, they can still delete or tamper with your backups.
Retention settings are weak or misused: Even when immutability is enabled, admins sometimes set short or flexible retention periods. Ransomware gangs love this. They infiltrate the system, shorten the retention window, and wait for the system to delete your older backups automatically.
Backups aren’t isolated from your main network: If your backups are on the same network or share credentials with production servers, ransomware can attack them too. Attackers simply move laterally across the network, lock your backups, or completely delete those “immutable” copies.
Weak Authentication and Shared Admin Access: When the same set of credentials manages both your main system and your backups, immutability doesn’t mean much anymore. One stolen password, and you lose both your live data and your chance of recovery.
Misleading Marketing by Vendors: Some vendors call “snapshots” or “version history” immutable, but you can still delete or roll them back. Others offer “soft delete” features, but you only have a limited time to recover your data.
Insider Threats and Human Error: Even the best security is useless if someone within the company disables immutability or changes the retention settings. One careless click or someone with malicious intent, and all your backups lose their protection.
Many so-called “immutable” backups don’t actually work – they rely on trust or someone correctly setting the right options, rather than on true, enforced immutability. If you want real protection, your backups must be locked as write-once, read-many (WORM), kept separate from your main systems (physically or logically), and governed by tamper-proof retention policies. This should also be combined with multi-factor authentication and strict access controls. When ransomware strikes, only truly immutable backups will save your data from being lost forever.
Frequently Asked Questions (FAQs)
Immutable backups are copies of your data that, once created, cannot be altered, deleted, or overwritten. This ensures that your information remains secure and recoverable, even if your main system is affected by ransomware, malware, or human error.
Many backups marketed as “immutable” fail because they rely only on software settings or admin permissions instead of true storage-level immutability. If attackers gain access, they can modify retention settings or delete the data entirely.
Ransomware often spreads across networks and targets backups to prevent recovery. If your backups aren’t isolated or locked with write-once, read-many (WORM) technology, attackers can encrypt or erase them – making recovery nearly impossible.
Just ask your backup provider a few straight questions:
Can anyone touch, change, or delete the backups before the time’s up?
Are you using WORM or object-lock technology to protect them?
Are the backups totally separate from your main network?
If you get a “no” to any of these, your backups aren’t as safe as you think.