Windows 10: Problem scanning certain files with windows defender

Hello

My windows defender has started having errors that stop working, stops and cannot be restarted, unless you start it from services.msc. Yesterday the antivirus was working fine, today I have updated to April 14, 2020 — KB4549951 cumulative update. I have applied the last defender definition.

I think that i have located the source of the error and it consists of the antivirus stopping when it tries to scan any file whose name is like this:

filename..ext

For example, filename..txt

If you scan filename.txt or filename...txt it does not produce any error, it is only when the file name ends with a point before the file extension.

Any solution?

:)

 

Problem scanning certain files with windows defender

This seemed so unlikely that I had to try going back and test it again. I restored my Macrium image from two days ago and confirmed Defender could scan a 'double-dot' file name....





... then updated just the definitions and confirmed that scanning the same file would kill the Windows Defender Antivirus Service. The only difference is the antivirus definitions version, confirming that this was the trigger for the bug.





That was a remarkable piece of detective work @Pilovar, how on earth did you discover that a double-dot file name caused the bug?

 

defender scans

Hi Ian,

Thanks for posting your query on Microsoft Community.

This issue might occur if you have set any task scheduler for Windows Defender.

I suggest you to delete the task for Windows defender and check if it helps.

Follow the below steps:

• 
  Search and open Schedule tasks.
  
• 
  In the left-hand menu, open the Task Scheduler Library, then select
  Microsoft >Windows >Windows Defender.
  
• 
  Double-click Windows Defender Scheduled Scan.
  
• 
  Select the Triggers panel, then select Delete.
  

Hope it helps, reply to us with the status of your issue. We will be happy to assist you.

 

right click scan in windows defender?


thanks for that.. i didn't notice the tutorial section :x

I did the suggested registry change and it's now listed on the desktop context menu.. but all this does is ask if I want to open it, update, or start a scan... I was hoping for the option where you right click a specific file and it will have listed 'scan with windows defender' like other antivirus programs have.. MSE had it. I'll keep looking around to see if I can find it in the meantime..