Malwarebytes realtime scan slows down Parallels hibernate

[smuda]

Hi!

I recently installed Malwarebytes evaluation on my physical mac with no threats found. After installation of Malwarebytes, hibernating a guest mac in Parallels 13.0.1 (42947) takes a lot of time (read several minutes). Disabling realtime protection in Malwarebytes restores the speed to seconds. 

If I could have found how to create the System Snapshot, I would have. The physical mac is a MacBook Pro, 15" with Sierra 10.12.6, 16GB internal memory. The virtual mac is Sierra 10.12.6, 8 GB internal memory.

Smuda

[treed]

When you talk about "hibernating" a guest Mac, are you referring to the act of suspending a Parallels VM containing a macOS system? Or so you mean putting the macOS system in a Parallels VM to sleep?

[smuda]

I'm talking about using the Parallels menu Action->Suspend.

[treed]

I can't duplicate that here. Where do you have your VM files stored? Also, does turning off real-time protection in Malwarebytes change anything?

[smuda]

The pvms are stored under ~/Documents/Parallels. I suppose thats the default. The mac pvm is 68 GB. (It used to be 240 GB before deleting a lot of snapshots)

Turning off Real-Time Protection changes the time to suspend the VM from minutes to seconds. Turning on Real-Time Protection makes it take minutes again.

The problem affects the Mac guest, not the other Windows guests. 

[treed]

That's very odd. I have a number of Mac VMs in that same folder, and can't reproduce the problem. It's also odd that it's only affecting the Mac VM, and not the Windows VMs. Even odder since Malwarebytes shouldn't be monitoring those files in any way.

One question... is Malwarebytes installed on the Mac guest system itself, or just on the host Mac?

[smuda]

It's just installed on the host. Is there anything I can try?

Otherwise I'll just leave the Real-Time Protection off.

[treed]

Can you try restarting your computer, and see if the problem still happens after a restart?