Windows 10: False positive for executable in MDE for 365

Hey community, recently users from our end created python script .py and converted it into executables .exe using pyinstaller.exe. During the compilation, MDE alerted on the executables and send it to our security dashboard microsoft defender 365. Upon investigation, the script is not malicious and the alert is false positive. How do we fine tune this or approach this issue from security perspective?

:)

 

False positive for desktop shortcut scanner.lnk

The 1.239.488.0 virus / spyware definition update that rolled out about 24 hours ago appears to be producing a false positive for any shortcut placed on the desktop called "Scanner.lnk". I can consistently replicate a false positive for Trojan:Win32/FakeSysdef
with the following steps.

• Create a shortcut to an exe file.
• Place the shortcut on the desktop.
• Name the shortcut "Scanner".
• Run "Quick Scan".

I don't get the same result by directly scanning the file, nor by uploading the file to www.virustotal.com, so it would appear this is as a result of a heuristic rather than a file content analysis. I also don't get the same result with a shortcut that links
to a website.

Can anyone else replicate? How can we go about getting the Windows Defender team to reconsider this heuristic? It's a bit heavy-handed.

 

False Positive for AV

It's common to nearly all anti-virus software these days to have some false positives, it's sort of a "Better safe than sorry" philosophy. Most good ones let you dismiss false positives though in my experience. An example would be a blacklisted EXE name. I used to play a game that had an executable names "Joshua.exe" Aparantly a common virus also used that name, and the AV went nuts. Fortunately in my case I was able to whitelist the application.

 

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.