Azure Suspicious VM Extension Installation

Triggers

• A Microsoft Entra Identity is using a highly permissive role within a Resource Group or Subscription scope to install and execute a VM extension without explicit consent or an audit trail. This is unusual for the identity.

Possible Root Causes

• Unauthorized Access: An attacker has gained access to a Microsoft Entra Identity and is using it to install a VM extension without permission.
• Misconfigured Security Settings: A Microsoft Entra Identity has been granted excessive permissions, allowing them to install VM extensions.
• Exploitation of a Vulnerability: A security flaw in Azure�s VM extension deployment process is being leveraged.
• Human Error: Mistakes during VM management or maintenance have led to unintended installations.
• Legitimate Activity: A valid identity, which typically does not interact with VM extensions, is installing an extension to fulfill a job function.

Business Impact

• Data loss or corruption due to unauthorized access.
• System compromise or ransomware attacks.
• Unplanned changes, service disruptions, or downtime for critical services.
• Compliance and regulatory issues due to inadequate security controls.

Steps to Verify

• Review Azure Activity Logs for other suspicious extension deployments.
• Investigate the user or service principal responsible for the deployment.
• Validate the VM extension configuration and associated permissions.
• Analyze network traffic and system logs for additional indicators of compromise (IOCs).
• Conduct a thorough security audit and risk assessment to identify vulnerabilities and implement necessary remediation actions.