Azure Blob Container Access Level Modification

Elastic Stack Serverless Security

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: 5m

Searches indices from: now-25m (https://www.elastic.co/guide/en/elasticsearch/reference/current/common-options.html#date-math[Date Math format], see also Additional look-back time)

Maximum alerts per execution: 100

References:

• https://docs.microsoft.com/en-us/azure/storage/blobs/anonymous-read-access-prevent

Tags:

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

Version: 7

Rule authors:

• Elastic

Rule license: Elastic License v2

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

Framework: MITRE ATT&CKTM

• Tactic:

  • Name: Discovery
  • ID: TA0007
  • Reference URL: https://attack.mitre.org/tactics/TA0007/

• Technique:

  • Name: Cloud Service Discovery
  • ID: T1526
  • Reference URL: https://attack.mitre.org/techniques/T1526/

• Tactic:

  • Name: Initial Access
  • ID: TA0001
  • Reference URL: https://attack.mitre.org/tactics/TA0001/

• Technique:

  • Name: Exploit Public-Facing Application
  • ID: T1190
  • Reference URL: https://attack.mitre.org/techniques/T1190/