Windows 10 feezes with MB 3

[John A]

Current release Windows 10
Defender

I start Malwarebytes at login, not Windows Startup to avoid an issue with Windows user profiles.
- Turned off "Start Malwarebytes at Windows startup"
- Added the MB shortcut to C:\Users\<username>\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup

 

System runs well until I add the following "Process" exclusion to Defender:
   C:\Program Files\Malwarebytes\Anti-Malware\MBAMService.exe

On restart, after Malwarebytes UI appears (sometimes earlier, sometimes after the UI is initially closed), Windows totally freezes, only way to restart is to force power off using the power button.

I can easily reproduce this on two computers.

To recover:

• Start Windows in Safe Mode
• Delete Malwarebyres startup entry
• Start Windows normally
• Delete MBAMService.exe process from Defender exclusion list
• Add the MB shortcut to C:\Users\<username>\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup again
• Restart Windows
• All good

 

Note: Excluding other Malwarebytes processes from Defender does not cause this issue.