Fix Malwarebytes Service High CPU on Windows

This guide walks you through the most effective ways to fix the Malwarebytes service (MBAMService) using unusually high CPU on Windows. You’ll learn how to identify the cause, apply the fixes, and prevent it from happening again.

What You’ll Need

• Administrator access to your Windows PC
• The latest version of Malwarebytes installed
• A few minutes to restart the service or your PC if needed

Step-by-Step

1. Check the current CPU usage. Press Ctrl+Shift+Esc to open Task Manager. Go to the Processes tab and look for Malwarebytes Service or MBAMService.exe. Note the CPU percentage. If it’s consistently above 30-40% when idle, proceed with the fixes.
2. Update Malwarebytes to the latest version. Open Malwarebytes, click Settings (gear icon), then About. Click Check for updates. If an update is available, install it and restart your PC. Outdated versions often have bugs that cause high CPU usage.
3. Restart the Malwarebytes service. Press Win+R, type services.msc, and press Enter. Scroll to Malwarebytes Service. Right-click it and select Restart. This clears temporary glitches without a full reboot.
4. Disable real-time protection temporarily. Open Malwarebytes, go to Settings > Security, and toggle off Real-Time Protection. Wait 30 seconds, then turn it back on. This forces the service to reload its drivers and often resolves high CPU.
5. Exclude Malwarebytes from other security software. If you have another antivirus (like Windows Defender), add Malwarebytes’ installation folder (usually C:\Program Files\Malwarebytes\Anti-Malware) to its exclusions. Also add the following processes: MBAMService.exe, MBAMWsc.exe, and mbam.exe. Conflicts between two real-time scanners can cause constant scanning loops.
6. Adjust Malwarebytes scan settings. Open Malwarebytes, go to Settings > Scan. Under Scan Options, uncheck Scan for rootkits and Scan within archives if they are enabled. These features are resource-heavy. Keep the standard threat scan enabled.
7. Repair Malwarebytes installation. Go to Settings > General and click Repair. This reinstalls missing or corrupted files without removing your settings. Restart your PC after it finishes.
8. Perform a clean reinstall. If nothing else works, uninstall Malwarebytes via Settings > General > Uninstall. Then download the latest installer from the official site and reinstall. This resets the service to a fresh state.

Common Mistakes

• Killing the service in Task Manager. Ending MBAMService.exe can leave Malwarebytes in a broken state. Always restart it via services.msc instead.
• Disabling real-time protection permanently. Turning it off and leaving it off exposes your PC to threats. Use it only as a temporary test.
• Ignoring Windows updates. Outdated Windows can cause driver conflicts with Malwarebytes. Always install the latest Windows updates.
• Adding exclusions to the wrong folder. If you exclude the wrong path, the conflict persists. Double-check the folder path in File Explorer.

Tips

• Schedule scans during idle time. In Malwarebytes, go to Settings > Scan > Schedule Scan and set it to run when you’re not using the PC.
• If you have an SSD, high CPU from scanning is less noticeable, but the fix is the same.
• Use the Resource Usage column in Task Manager to confirm it’s really Malwarebytes and not another process with a similar name.
• After applying any fix, wait 2-3 minutes before checking Task Manager again—the service may spike briefly during a scan.

Troubleshooting

If the CPU usage remains high after all steps:

• Boot Windows in Safe Mode (with Networking) and check Task Manager. If CPU is low in Safe Mode, a third-party driver or startup program is conflicting. Use Malwarebytes’ startup manager to disable suspicious items.
• Check if the issue happens only during scans. If so, reduce scan settings further or switch to a custom scan that excludes large folders (like your Downloads folder) you trust.
• If the service is stuck at 100% for more than 10 minutes, run a full system scan with Malwarebytes to rule out malware that might be causing the service to work overtime.
• If you’re on a corporate network, your IT policy may force certain scan settings. Contact your administrator before changing them.

Frequently Asked Questions

Why does Malwarebytes use high CPU even when idle?

It’s usually due to a conflict with another security program, an outdated version, or a corrupted service file. The steps above address all these causes.

Is it safe to disable real-time protection temporarily?

Yes, for a few minutes to test. But keep it on for normal use—it’s your main defense against active threats.

Will uninstalling and reinstalling remove my malware history?

No, your quarantine and scan history are stored separately and are preserved during a normal uninstall.

Can I add Malwarebytes to Windows Defender exclusions?

Yes, but you don’t need to if you’re using Malwarebytes as your primary antivirus. Do it only if you run both simultaneously.

How long does a full scan take?

A full scan can take 30-60 minutes depending on your disk size and speed. It will use high CPU during that time—that’s normal.

What if the problem only happens after a Windows update?

Uninstall the latest Windows update temporarily, restart, and see if CPU drops. If it does, wait for Malwarebytes to release a compatible update.

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