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Definition effect: DeployIfNotExists; For remediation: a managed identity that has the Contributor role

DeployIfNotExists is the Azure Policy effect used when a noncompliant resource should trigger deployment of a related configuration, such as a VM extension. Remediation tasks require a managed identity that has the role permissions needed to deploy the extension. Audit or Deny would only report or block resources. The managed identity is essential because Azure Policy performs the deployment on behalf of the assignment. This answer also follows operational scalability. Microsoft security architecture favors policy-driven deployment, agentless assessment, managed identities, and Defender workload plans where possible. Those mechanisms reduce manual configuration while keeping enforcement tied to the resource type, which is why the selected choice is stronger than manual or after-the-fact alternatives. The result is a direct exam-style implementation choice: it changes the required security behavior without relying on unrelated monitoring, manual cleanup, or excessive privilege. Official Microsoft source/topic: SC-500 Study Guide > Azure Policy built-in and custom definitions; Microsoft Learn > deployIfNotExists and remediation.

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