Description

File Integrity Monitoring (FIM) is a feature that monitors critical system files in Windows or Linux for potential signs of attack or compromise.

Rationale

FIM provides a detection mechanism for compromised files. When FIM is enabled, critical system files are monitored for changes that might indicate a threat actor is attempting to modify system files for lateral compromise within a host operating system.

Impact

File Integrity Monitoring requires licensing and is included in these plans:

• Defender for Servers plan 2

Audit

From Azure Portal

1. From the Azure Portal Home page, select Microsoft Defender for Cloud.
2. Under Management select Environment Settings.
3. Select a subscription.
4. Under Settings > Defender Plans, click Settings & monitoring.
5. Under the Component column, locate the row for File Integrity Monitoring.
6. Ensure that On is selected.

Repeat the above for any additional subscriptions.

Default Value

By default, Agentless scanning for machines is off.

References

1. https://learn.microsoft.com/en-us/azure/defender-for-cloud/file-integrity-monitoring-overview
2. https://learn.microsoft.com/en-us/security/benchmark/azure/mcsb-incident-response#ir-2-preparation---setup-incident-notification
3. https://learn.microsoft.com/en-us/azure/defender-for-cloud/file-integrity-monitoring-enable-defender-endpoint