I recently had a virus on my laptop, after a bit of searching I found this thread on the forum
It seemed to have the exact same issues with not being able to install Malwarebytes or use AdwCleaner, after reading the posts I followed the instructions on the last page opening up mmc.exe and remove the list of untrusted certificates. Then I was able to install MB and after a scan it deleted a coinminer virus.
Before all of this I noticed in Task Manager that Antimalware Service Executable was running high CPU and Memory percentages so I poked around in Windows Defender and found that there were exclusions added pointing to c/windows/services or something, I deleted those and scanned but it found nothing and thats why tried installing MB and it gave me this popup(image from other thread);
As I mentioned I followed instructions from the other thread and was able to install MB and remove the virus. But still I keep seeing Antimalware Service Executable in taskmanager so I right-clicked on it and went to the file location (C:\ProgramData\Microsoft\Windows Defender\Platform\4.18.1901.7-0), so I went to the properties of MsMpEng.exe and noticed in the security tab there are more Users and groups added than I normally see in other files.
Are these left-overs from the virus? If so can I delete them?