Why Azure Blob Storage Needs Backup: 5 Risks You Can’t Ignore

Object storage has evolved. No longer just a destination for archived files, it now serves as primary storage for mission-critical data in AI pipelines, analytics, and cloud-native apps. With this shift, the stakes for protecting that data have never been higher. 

Azure Blob Storage is one of the key cloud object storage platforms in the market as of today, used by thousands of organizations worldwide. Teams use it for storing high-performance computing (HPC) workloads, logs and traces from cloud-native services, ETL and data-transformation outputs, AI and ML training sets, and analytics datasets. 

Why Native Features Do Not Ensure Comprehensive Data Protection 

Azure Blob Storage offers built-in durability and operational safeguards like redundancy, soft deletes, and versioning. These features help combat hardware failure risks and reduce everyday errors. 

What they do not provide is true resilience when the control plane itself is affected, for example, compromised credentials, over-permissive automation, misapplied policies, or large-scale operator error. Because many of these features mirror the current state by design, they can replicate a bad state, such as deletes, corruptions, or policy changes, just as fast as a clean one. This means that even with native features enabled, your data remains vulnerable to a range of real-world risks, some of which are easy to overlook until it’s too late. 

Five risks you cannot ignore for Azure Blob Storage

Security Incidents 

Azure Blob Storage holds vast amounts of high-value data, often at the petabyte scale. Well-documented programmatic access to such data is a hacker’s dream. Targeted ransomware can encrypt or corrupt terabytes of data, while compromised credentials or insider misuse can trigger deletions, key rotations, and policy changes. Tenant-level compromise can also alter lifecycle or immutability policies. 

Documented Incident: Microsoft’s threat intelligence team reported a campaign in which a threat actor known as Storm‑0501 used stolen credentials to compromise Azure tenants. The attacker deleted recovery locks and immutability policies, created a new encryption scope for Azure Blob Storage and then encrypted the data using keys stored in a newly created Key Vault. After encrypting hundreds of terabytes of data, they deleted the encryption key and ransom notes were sent through Microsoft Teams. [^1] 

This incident illustrates how compromised credentials and misuse of programmatic access can allow attackers to encrypt or delete massive data sets and manipulate lifecycle or immutability policies. 

Administrative Misconfigurations 

Customer misconfigurations are a common source of disruption and data loss in Azure Blob Storage. Because people configure access policies, lifecycle rules, legal holds, firewall and networking settings, and tiering, there is ongoing risk from human error. Accidental deletes or overwrites can remove critical prefixes or replace objects unexpectedly. Misconfigured lifecycle policies may expire data too early or move it to cold tiers that break analytics. Disabled versioning/soft delete, or incorrect key rotation can also make data inaccessible or unrecoverable. 

Documented Incident: A user deleted a resource group containing an Azure Data Lake Storage account and then recreated a storage account with the same name. They discovered they could not restore the deleted data even though Azure offers a 14‑day recovery window for storage accounts. Microsoft support explained that if a storage account is deleted and then recreated with the same name, recovery fails. [^2] 

The underlying issue was that the user had not enabled soft delete, versioning or resource locks, which could have prevented or mitigated accidental deletion. The absence of such protection and the re‑creation of the account effectively destroyed recovery options.  

Compliance and Governance Enforcement 

Increasing regulatory scrutiny drives stricter immutability and retention. While well-intended, these controls can delay fixes, fragment datasets, and disrupt workflows. WORM (write once, read many) policies, for example, can block emergency remediation by preventing deletes or edits, which in turn delays containment and consumes unnecessary storage. Misconfigured residency settings can block cross-border replication, breaking recovery objectives.  

Documented Incident:  A user of Azure Blob Storage created a storage account in a test environment and when he was done with what he needed to, deleting the environment was not possible. It was because of the immutability policies, and the only workaround was to change each blob’s policy individually. The user mentions that while the immutability policies were excellent for ensuring compliance in production, there is not a way to play with it and understand it in an ephemeral fashion or test environment. [^3] 

Operational and Platform Failures 

In Azure Blob Storage, small faults can cause disruption and, at times, operator-induced data loss. Because many applications and pipelines interact with Blob Storage around the clock, the surface area for failure is large. Failed uploads or commits, ETL and pipeline errors, SDK or client version mismatches, missing integrity checks, unsafe retries that overwrite good data, and tooling defects in the tenant’s environment can all lead to corruption or temporary unavailability. 

Documented Incident: A cooling system failure at Azure’s South Central US data center caused widespread hardware shutdowns to prevent damage. The incident resulted in cascading failures affecting not just primary workloads but also backup and disaster recovery mechanisms stored in Blob Storage. Organizations experienced widespread service disruption and issues in storage-dependent workflows during recovery, highlighting how cross-service dependencies can limit practical failover options even with geo-redundancy. [^4] [^5] 

This incident shed light on the importance of cross-region and cross-cloud backups, and ensuring multi-cloud portability of backups.  

Supply Chain Compromise by the Cloud Vendor 

Every business is exposed to supply chain risk, and cloud providers are not exempt. Supply chain issues from Azure’s vendors can ripple outward and cause disruptions for many businesses. Beyond software supply chain issues, provider-originated problems such as service bugs, faulty operational changes, IAM misconfigurations, or encryption key mishandling can propagate to customers and cause data loss or disruption even when tenant configurations are correct. 

Documented Incident: Storm-0558, a China-based threat actor, obtained a Microsoft Account (MSA) consumer signing key and forged authentication tokens. Beginning May 15, 2023, they accessed email data for about 25 organizations by exploiting a validation error that let MSA keys sign Azure AD tokens. Subsequent research argued the compromised key could have been accepted by other apps that use “Login with Microsoft,” indicating potential impact beyond email. [^6] 

Immutable, Separate Governed Backup Ensures Resilience and Recoverability 

If there is one solution that could ensure operational resilience during all the above-mentioned situations, it is an immutable, logically air-gapped backup, with independent policies and point-in-time recovery. 

By “logically air-gapped,” we mean backups governed under separate credentials and roles and protected by immutability or time-based retention, so changes in the production tenant cannot modify or delete backup copies. If production access or configuration is tampered with, those copies remain intact, and you have a clean, known-good restore path at scale. 

With a tamper-proof backup, stored separately (in another region) within Azure Blob Storage, or even better, in another cloud platform like Amazon S3 or Google Cloud Storage, you can put yourself in a strong position to recover from the disruption and data loss caused by any of the above situations.  

That’s exactly where HYCU helps. Our joint solution with Dell provides cost-efficient, ransomware-proof backups for Azure Blob Storage, so you can recover confidently, even in worst-case scenarios. 

Easy to deploy and manage. Immutable by design. 

Check out www.hycu.com to see how HYCU + Dell delivers cost-efficient and resilient backup for Azure Blob Storage. 

_________________________________________________________________________________ 

References: 

1. Microsoft Threat Intelligence. (2025, August 27). Storm-0501’s evolving techniques lead to cloud-based ransomware. Microsoft Security Blog.
2. Nguyen, T. (2025, August 20). [URGENT] Accidental deletion of Azure Data Lake Storage Gen2 account – Can data be restored? Microsoft Q&A.
3. Lapointe, S. (2023, December 8). How to delete an Azure storage account with an unlocked immutability policy. Code is a Highway.
4. Moss, S. (2018, September 4). Microsoft Azure suffers outage after cooling issue. DataCenterDynamics.
5. Azure DevOps SRE Team. (2018, September 10). Postmortem – VSTS outage – 4 September 2018. Microsoft DevBlogs.
6. Tamari, S. (2023, July 21). Compromised Microsoft key: More impactful than we thought. Wiz Blog.