True Immutability: All You Need for Ransomware Protection
According to 2025 ESG research, 66% of organizations have experienced at least one ransomware attack in the past two years, and 96% of those attacks target backup data.
So, when—not if—a breach happens, and your business, reputation, and career are on the line, immutable backup storage is your best and last line of defense. However, if 'immutable' data can be overwritten by a backup or storage admin, a vendor, or an attacker, then it is NOT a truly immutable storage solution.
That's why Object First is on a mission to help organizations understand what True Immutability is and why it matters. By educating the market and delivering a solution that enforces immutability at every layer, we want to help businesses strengthen their cyber resilience and confidently meet security and compliance demands.
What Is True Immutability?
True Immutability means zero access to destructive actions. No one—not even the most privileged admin or a fully compromised attacker—can modify or delete backup data. At its core, True Immutability is built on an 'assume breach' mindset. Even if your credentials are stolen, your infrastructure is compromised, or an insider goes rogue, your backup data stays untouchable.
Why emphasize this? Because not all solutions that claim immutability actually deliver it. Object First introduced the concept of True Immutability to clearly differentiate from weaker, policy-based protections that can still be bypassed under the right (or wrong) conditions.
This is what we call Zero Access, and it must be independently verified through third-party security testing. It’s enforced across every layer of the immutable storage stack, including hardware that is locked by the appliance vendor and cannot be modified by the Admin:
S3 Buckets: In compliance mode, data cannot be modified or deleted—no exceptions.
Storage Application: Admin-level access is restricted; configuration cannot override data immutability.
Operating System: Root-level access is blocked entirely. Only pre-approved service procedures are allowed, with 8-eyes control for rare cases.
Hardware/BIOS: Physical access is required for any firmware changes. Devices are locked by the vendor and cannot be modified remotely.
True Immutability vs. Standard (Not True) Immutability
Many vendors claim to offer immutable backup storage, but what they really provide is a policy-based configuration that can still be changed, bypassed, or disabled by administrators or attackers with elevated privileges.
True Immutability, on the other hand, enforces Zero Access by design, not by policy. It cannot be disabled or overwritten—not even by root users—and must be independently verifiable through third-party testing.
The table below highlights the key differences between True Immutability and standard “immutable” configurations:
| Capability | True Immutability | Standard (Policy-Based) Immutability |
|---|---|---|
Protection Level | Enforced at the storage layer—cannot be modified or deleted by anyone | Enforced via software or configuration settings—can be changed or removed |
Admin Privileges | Admins have zero access to destructive actions | Admins may retain root access or override protections |
Zero Trust Alignment | Fully aligns with Zero Trust architecture and the Assume Breach principles | Partial alignment—trusts privileged accounts to enforce policy |
Third-Party Verification | Must be independently tested and verified | Rarely validated by external security audits |
Immutability Scope | Applies across hardware, OS, storage application, and S3 buckets | Typically limited to S3 object lock or backup software settings |
Tamper Resistance | Cannot be disabled remotely—even by insiders or vendors | Can be reverted by reconfiguring policies or using recovery tools |
Update & Maintenance Control | Firmware/OS changes allowed only via controlled vendor service channels (8-eyes model) | Updates and resets often possible with admin or root credentials |
Benefits of True Immutability
Now that the difference between true and standard immutability is clear, the value of adopting True Immutability becomes undeniable.
Here are five key benefits organizations gain with True Immutability:
1. Ransomware Protection: True Immutability ensures that backup data remains untouchable even if attackers breach your infrastructure. With Zero Access at every layer, there is simply no way to modify or delete backups, no matter how compromised the environment is.
2. Insider Threat Prevention: Most immutability models break under the assumption that admins can be trusted. True Immutability removes that assumption entirely. Even malicious insiders or mistakenly privileged users are blocked from taking destructive actions.
3. Regulatory Compliance: From GDPR, HIPAA, NIS2, and beyond, many regulations require that data be retained in a non-rewritable, non-erasable format. True Immutability enforces this at the storage level, meaning there are no loopholes or policy gaps.
4. Operational Simplicity: The underlying appliance enforces immutability, so no additional configuration, scripting, or monitoring is needed. It’s secure by default and remains that way across upgrades, patches, and staffing changes.
5. Zero Trust Alignment: True Immutability extends the Zero Trust model beyond identity and access control. It assumes credentials will be compromised and compensates by enforcing immutability in a way that’s completely independent of admin trust.
3 Steps to Achieve True Immutability
Achieving True Immutability through Zero Access requires a deliberate design that spans protocol, architecture, and hardware.
Here are the three non-negotiable components every secure data storage strategy must include:
Step 1: Leverage S3 Object Storage
Only S3 object storage provides inherent security, with native immutability built directly into its protocol and APIs. This foundational design ensures that once data is written, it cannot be altered or deleted.
In contrast, traditional block and file storage systems lack native immutability and instead rely on proprietary, bolt-on solutions that were added as an afterthought.
Step 2: Ensure Zero Time to Immutability
Ensuring that backup data is immutable from the moment it is written is critical for preventing unauthorized alterations, maintaining data integrity, and defending against ransomware.
The proven and most secure way to achieve this is through S3 versioning combined with Object Lock, which enforces immutability when an object is created in the storage system.
Step 3: Utilize a Purpose-Built Target Appliance
Purpose-built backup appliance means a standalone storage device that is configured and optimized for storing backup data.
There are two types: integrated appliances, which combine backup software and storage in a single system, and target appliances, which provide turn-key storage devices for external backup software such as Veeam.
Only a purpose-built, turn-key backup S3 Target Appliance delivers Zero Trust Data Resilience by properly separating software and storage and allowing independent security testing.
Use Cases for True Immutability
True Immutability isn’t reserved just for large enterprises. It brings tangible perks to organizations of all sizes, especially those with compliance requirements, limited IT resources, or elevated ransomware risk.
Here’s who needs it most:
Enterprises requiring airtight backup resilience: For large organizations with complex environments and high-value data, True Immutability eliminates the single points of failure that attackers often exploit, even when privileged access is compromised.
SMBs seeking simple, foolproof protection: With limited staff and fewer resources to monitor backup security, small and mid-sized businesses benefit from a solution that’s secure by default and verifiably immutable, without the complexity of DIY management.
Regulated industries like healthcare, finance, and legal: These sectors face strict mandates to retain data in non-rewritable, non-erasable formats. True Immutability with Compliance Mode ensures compliance with frameworks like HIPAA, GDPR, or NIS2.
Organizations with hybrid or remote IT operations: Distributed environments introduce more variables and vulnerabilities. True Immutability removes the need for hands-on monitoring or trusted admin access, making it ideal for hybrid and remote-first infrastructures.
Teams using backup-as-a-service (BaaS) or external MSPs: When backup responsibilities are outsourced, internal control is limited. True Immutability acts as a safeguard against misconfigurations, privilege creep, or insider risk—whether internal or third-party.
IT teams facing skills shortages or high staff turnover: When experienced personnel are hard to find (or frequently rotate), complex backup solutions become a liability. True Immutability provides a set-it-and-trust-it foundation that doesn’t rely on perfect execution from every team member.
Meet Ootbi: Purpose-Built Backup Storage for Veeam with True Immutability
Ootbi (Out-of-the-Box Immutability) by Object First protects Veeam customers from ransomware threats, delivering secure, simple, and powerful backup storage with True Immutability.
Leverages S3 Object Storage: Built on a fully documented, open standard with native immutability, enabling independent penetration testing and third-party verification.
Enforces Zero Time to Immutability: Backup data becomes immutable the moment it is written—no gaps, no landing zones.
Runs on a Target Storage Appliance: Separates storage from backup software, eliminating DIY risks and offloading operational security to the vendor—no security expertise required.
With Ootbi, it's impossible for anyone—a backup or storage admin, a vendor, or an attacker—to maliciously or accidentally delete, overwrite, or tamper with your data under any circumstances.
Book a live Ootbi demo and see how it keeps your backup data protected and recoverable, no matter what happens—whether ransomware, insider threats, or credential breaches.