Windows 10: Windows Defender sudetection within WinSxS yesterday - false positive?

As per the subject line: Defender just casually told me yesterday evening that WindowsExplorer.adml within C:\Windows\WinSxS\amd64_microsoft-windows-w..lorer-adm.resources_31bf3856ad364e35_10.0.18362.1_pl-pl_954343e68e282099 has been removed as it allegedly contains HackTool:JS/Revobfoos.A






This is obviously nonsense - this file has been put there by OS back in the end of Jul (according to its date/time stamp) and I dutifully just restored it.

I did this file check today again and Defender is okay with it. I also checked with other scanners (as I do weekly) and all is well.

There is similar file under C:\Windows\WinSxS\amd64_microsoft-windows-w..lorer-adm.resources_31bf3856ad364e35_10.0.18362.1_en-us_95faf8061ffdb6de with the same date/time stamp.

So, any ideas? Or - as I suspect - false positive? But scary thing is that removal was just so casual and it was only because I habitually check contents of notifications, I spotted it.

I can share this file should somebody want to take a look?

What is this file by the way?

--

ARGH! Can you please move to AntiVirus, Firewalls and System Security section where it should belong?

:)

 

defender false positive

Hi Bob,

To better assist you, kindly verify the following:

• Where did you submit the file about Windows Defender being false positive?
• Right after the recent Windows 10 update, your Zara Radio stopped working?
• Regarding the 404 error, what application were you using when you got that error?

Let us know.

 

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

 

Why does Windows Defender not understand "False Positive"?

Almost daily now, I've had to clear a "threat" from Defender's "actions needed" list on a specific program that is a false positive.

How do I make it work as expected?