Introduction to Azure Defender for Storage

Azure Defender for Storage is an Azure-native layer of security intelligence that detects unusual and potentially harmful attempts to access or exploit your storage accounts. It utilizes the advanced capabilities of security AI and Microsoft Threat Intelligence to provide contextual security alerts and recommendations.

Security alerts are triggered when anomalies in activity occur. These alerts are integrated with Azure Security Center, and are also sent via email to subscription administrators, with details of suspicious activity and recommendations on how to investigate and remediate threats.

What are the benefits of Azure Defender for Storage?

Azure Defender for Storage provides:

• Azure-native security — With 1-click enablement, Defender for Storage protects data stored in Azure Blob, Azure Files, and Data Lakes. As an Azure-native service, Defender for Storage provides centralized security across all data assets managed by Azure and is integrated with other Azure security services such as Azure Sentinel.
• Rich detection suite — Powered by Microsoft Threat Intelligence, the detections in Defender for Storage cover the top storage threats such as anonymous access, compromised credentials, social engineering, privilege abuse, and malicious content.
• Response at scale — Security Center’s automation tools make it easier to prevent and respond to identified threats. Learn more in Automate responses to Security Center triggers.

What kind of alerts does Azure Defender for Storage provide?

Security alerts are triggered when there’s:

• Suspicious access patterns — such as successful access from a Tor exit node or from an IP considered suspicious by Microsoft Threat Intelligence
• Suspicious activities — such as anomalous data extraction or unusual change of access permissions
• Upload of malicious content — such as potential malware files (based on hash reputation analysis) or hosting of phishing content

Alerts include details of the incident that triggered them, as well as recommendations on how to investigate and remediate threats. Alerts can be exported to Azure Sentinel or any other third-party SIEM or any other external tool.

Tip: It’s a best practice to configure Azure Defender for Storage on the subscription level, but you may also configure it on individual storage accounts.

Trigger a test alert for Azure Defender for Storage

To test the security alerts from Azure Defender for Storage in your environment, generate the alert “Access from a Tor exit node to a storage account” with the following steps:

1. Open a storage account with Azure Defender for Storage enabled.

2. From the sidebar, select “Containers” and open an existing container or create a new one.

3. Upload a file to that container.

Caution: Don’t upload a file containing sensitive data.

4. Use the context menu on the uploaded file to select “Generate SAS”.

5. Leave the default options and select Generate SAS token and URL.

6. Copy the generated SAS URL.

7. On your local machine, open the Tor browser.

Tip: You can download Tor from the Tor Project site https://www.torproject.org/download/

8. In the Tor browser, navigate to the SAS URL.

9. Download the file you uploaded in step 3.

Within two hours you’ll get the following security alert from Security Center: