Azure Blob Container Access Level Modificationedit

Identifies changes to container access levels in Azure. Anonymous public read access to containers and blobs in Azure is a way to share data broadly, but can present a security risk if access to sensitive data is not managed judiciously.

Rule type: query

Rule indices:

  • filebeat-*
  • logs-azure*

Severity: low

Risk score: 21

Runs every: 5 minutes

Searches indices from: now-25m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Cloud
  • Azure
  • Continuous Monitoring
  • SecOps
  • Asset Visibility

Version: 5 (version history)

Added (Elastic Stack release): 7.10.0

Last modified (Elastic Stack release): 7.13.0

Rule authors: Elastic

Rule license: Elastic License v2

Potential false positivesedit

Access level modifications may be done by a system or network administrator. Verify whether the username, hostname, and/or resource name should be making changes in your environment. Access level modifications from unfamiliar users or hosts should be investigated. If known behavior is causing false positives, it can be exempted from the rule.

Investigation guideedit

## Config

The Azure Fleet integration, Filebeat module, or similarly structured data is required to be compatible with this rule.

Rule queryedit

event.dataset:azure.activitylogs and azure.activitylogs.operation_name
:"MICROSOFT.STORAGE/STORAGEACCOUNTS/BLOBSERVICES/CONTAINERS/WRITE" and
event.outcome:(Success or success)

Threat mappingedit

Framework: MITRE ATT&CKTM

Rule version historyedit

Version 5 (7.13.0 release)
  • Formatting only
Version 4 (7.12.0 release)
  • Updated query, changed from:

    event.dataset:azure.activitylogs and azure.activitylogs.operation_name
    :MICROSOFT.STORAGE/STORAGEACCOUNTS/BLOBSERVICES/CONTAINERS/WRITE and
    event.outcome:(Success or success)
Version 3 (7.11.2 release)
  • Formatting only
Version 2 (7.11.0 release)
  • Updated query, changed from:

    event.dataset:azure.activitylogs and azure.activitylogs.operation_name
    :MICROSOFT.STORAGE/STORAGEACCOUNTS/BLOBSERVICES/CONTAINERS/WRITE and
    event.outcome:Success