Which of the following signs is not an indicator of Azure storage-based security incident?

Accessing an Azure storage account from a usual location is not considered an indicator of a security incident because it suggests normal behavior from a known and trusted source. In security incident response, unusual patterns of access or attempts to reach data from unexpected locations or devices are key indicators of potential unauthorized access or malicious activity.

In contrast, the other options indicate potential security risks. Multiple failed access attempts could indicate that someone is trying to brute-force their way into the storage account, suggesting a security incident might be occurring. Accessing data from unrecognized devices raises alarms as it signifies that an unknown or potentially compromised device might be trying to interact with the storage, increasing the likelihood of unauthorized access. Frequent access to sensitive files may also indicate suspicious activity, especially if the access is happening outside of normal business hours or patterns.

Thus, the best choice for what does not indicate a potential security incident is accessing the Azure storage account from a usual location, as it generally aligns with expected user behavior and suggests that the access is legitimate.