Windows 10: Win Defender not clearing threats

I've been using Win Defender on Win Version 2004 for some time. It recently has had strange behavior.

I ran a full scan and Defender identified several Potentially Unwanted Programs. They were mainly freeware program installation files. I clicked my chosen action for each but there was no indication that anything happened. I then looked for the identified files in File Explorer and manually deleted them. Nonetheless, Defender continued to identify the threat.

After manually deleting all the identified threats, I ran Defender again and the same threats were still identified even though the programs had been deleted.

I searched here and Google for this symptom but didn't find anything.

Any ideas?

:)

 

Clearing Windows Defender history

Hey, what you need to do is so simple, just follow the steps below exactly in order:

1. Turn OFF Real-time Protection
2. Turn OFF Cloud-delivered Protection
3. Go to this folder C:\ProgramData\Microsoft\Windows Defender\Scans\History\Service
4. Delete the contents in the folder
5. Turn ON Real-time Protection
6. Turn ON Cloud-delivered Protection

That's it... Now check protection History, it's empty.
Done!

 

Windows defender false positive - forced to allow threat

Windows defender has started to identify C:\Windows\System32\mshta.exe as a threat [normally reported as a Trojan Powessere.G]. I use mshta.exe to run an hta custom MsgBox - I have been hoping to keep using my current CustomMsgBox tool [batch file calling a vbs-hta file] until later this year when I hope to have had enough time to replace it with a PowerShell alternative.

Windows defender's notification lets me "allow the threat" but that seems to me to be a bigger security hole than is necessary - it will now ignore a potentially real intrusion when all I want to run is a genuine Windows component. My immediate problem is fixed but I would prefer to fix the false positive using the exclusions list.

I cleared the 'Allowed threats history' so I could use the exclusions list instead. I added C:\Windows\System32\mshta.exe to the file exclusions list and I checked that it had taken properly by checking the exclusions list both in the UI & in the Registry. But the exclusion made no difference, it continued to detect and block the exe.

I have repeated the attempt several times [by clearing the allowed threats list & exclusions list beforehand] and the results are the same every time
- allowing the threat works,
- using the exclusions list has no effect.

I studied the relevant tutorial but have not spotted an error in what I have been doing - Add or Remove Windows Defender Exclusions

Does anybody with experience of using the exclusions list to counter false positives have any suggestions for me?

Denis

 

Can't run Windows Defender

Win Defender Security Centre lists my Virus and Threat Protection as disabled. The message reads "Your Virus & threat Protection is managed by your organization."

This happened a month ago and was resolved when I thoroughly removed Malwarebytes, though it and Win Defender had co-existed without trouble for some years. Now Malwarebytes is gone, no other antimalware software in place. Anyone suggest what could be
disabling Win Defender?