Ensure Microsoft Defender for Servers is set to 'On'

Overview

Turning on Microsoft Defender for Servers enables threat detection, providing threat intelligence, anomaly detection, and behavior analytics in the Microsoft Defender for Cloud.

Rationale

Enabling Microsoft Defender for Servers allows for greater defense-in-depth, with threat detection provided by the Microsoft Security Response Center (MSRC).

Impact

Turning on Microsoft Defender for Servers in Microsoft Defender for Cloud incurs an additional cost per resource.

Two Defender for Servers plans exist:

Plan 1: Subscription only
Plan 2: Subscription and workspace

Default Value

By default, Microsoft Defender for Servers plan is off.

Remediation guidance

Remediate from Azure Portal

Go to Microsoft Defender for Cloud
Under Management, select Environment Settings
Click on the subscription name
Click Defender plans in the left pane
Under Cloud Workload Protection (CWP), locate Server in the Plan column, set Status to On
Select Save

Remediate from Azure CLI

Run the following command:

az security pricing create -n VirtualMachines --tier 'standard'

Remediate from PowerShell

Run the following command:

Set-AzSecurityPricing -Name 'VirtualMachines' -PricingTier 'Standard'

Multiple Remediation Paths

Azure

SERVICE-WIDE (RECOMMENDED when many resources are affected): Assign Azure Policy initiatives at management group/subscription scope and trigger remediation tasks.

az policy assignment create --name <assignment-name> --scope /subscriptions/<subscription-id> --policy-set-definition <initiative-id>
az policy remediation create --name <remediation-name> --policy-assignment <assignment-id>

ASSET-LEVEL: Apply the resource-specific remediation steps above to the listed non-compliant resources.

PREVENTIVE: Embed Azure Policy checks into landing zones and IaC workflows to block or auto-remediate drift.

References for Service-Wide Patterns

Azure Policy overview: https://learn.microsoft.com/en-us/azure/governance/policy/overview
Azure Policy remediation: https://learn.microsoft.com/en-us/azure/governance/policy/how-to/remediate-resources
Azure Policy initiative structure: https://learn.microsoft.com/en-us/azure/governance/policy/concepts/initiative-definition-structure

Operational Rollout Workflow

Use this sequence to reduce risk and avoid repeated drift.

1. Contain at Service-Wide Scope First (Recommended)

Azure: assign policy initiatives at management group/subscription scope and run remediation tasks.

az policy assignment create --name <assignment-name> --scope /subscriptions/<subscription-id> --policy-set-definition <initiative-id>
az policy remediation create --name <remediation-name> --policy-assignment <assignment-id>

2. Remediate Existing Affected Assets

Execute the control-specific Console/CLI steps documented above for each flagged resource.
Prioritize internet-exposed and production assets first.

3. Validate and Prevent Recurrence

Re-scan after each remediation batch.
Track exceptions with owner and expiry date.
Add preventive checks in IaC/CI pipelines.

Query logic

These are the stored checks tied to this control.

Azure subscriptions without Microsoft Defender for Servers

Connectors

Microsoft Azure

Covered asset types

Connector

Expected check: eq []

{
  connectors(
    where: { pricing_SOME: { name: "VirtualMachines", pricingTier: "Free" } }
  ) {
    ...AssetFragment
  }
}