High CPU Usage by Microsoft Defender Antivirus on Windows Server 2019 Azure VMs

Hi nsojitra​,

The CPU spikes you’re seeing from MsMpEng.exe around 4:40 - 4:55 PM are expected on Windows Server 2019 Azure VMs, as Defender runs background maintenance tasks like cloud protection updates during that window.

To mitigate the impact on performance:

- Adjust scan settings: lower ScanAvgCPULoadFactor, run scans only when idle, or schedule them in off-peak hours.

- Add exclusions for specific files or processes that may trigger high CPU.

- Monitor performance with tools like Process Monitor to fine-tune settings.

- Ensure no other antivirus is running alongside Defender.

These steps are supported and help reduce CPU usage without disabling critical protection.

https://learn.microsoft.com/en-us/defender-endpoint/troubleshoot-performance-issues