To expand the threat protections provided by Microsoft Defender for Storage, Microsoft added a new preview alert.
Alert (alert type)
Description
MITRE tactic
Severity
PREVIEW – Access from a suspicious application (Storage.Blob_SuspiciousApp)
Indicates that a suspicious application has successfully accessed a container of a storage account with authentication. This might indicate that an attacker has obtained the credentials necessary to access the account, and is exploiting it. This could also be an indication of a penetration test carried out in your organization. Applies to: Azure Blob Storage, Azure Data Lake Storage Gen2
The preview alert that detected this was called “Anonymous scan of public storage containers”. To provide greater clarity about the suspicious events discovered, we’ve divided this into two new alerts. These alerts are relevant to Azure Blob Storage only.
Microsoft has improved the detection logic, updated the alert metadata, and changed the alert name and alert type.
A successful discovery of publicly open storage container(s) in your storage account was performed in the last hour by a scanning script or tool.
This usually indicates a reconnaissance attack, where the threat actor tries to list blobs by guessing container names, in the hope of finding misconfigured open storage containers with sensitive data in them.
The threat actor may use their own script or use known scanning tools like Microburst to scan for publicly open containers.
✔ Azure Blob Storage ✖ Azure Files ✖ Azure Data Lake Storage Gen2
A series of failed attempts to scan for publicly open storage containers were performed in the last hour.
This usually indicates a reconnaissance attack, where the threat actor tries to list blobs by guessing container names, in the hope of finding misconfigured open storage containers with sensitive data in them.
The threat actor may use their own script or use known scanning tools like Microburst to scan for publicly open containers.
✔ Azure Blob Storage ✖ Azure Files ✖ Azure Data Lake Storage Gen2