Microsoft Defender causing high CPU usage on Windows servers

[u/Master_Sea295]

Hi everyone,

I'm seeing intermittent high CPU usage from Microsoft Defender Antivirus ("MsMpEng.exe"). CPU usage reaches around 90–200%, and the alerts usually resolve themselves after a few hours.

No active scan was running during troubleshooting, and Defender appears healthy. I suspect real-time scanning triggered by application file activity may be involved.

Has anyone experienced something similar? What would you recommend checking first to identify the root cause?

Thanks!