Windows Defender - Files Scanned Doubled?

[Unlucky_Pete]

After downloading some files on Windows 10, I decided to scan them with Windows Defender and noticed something very odd about the scan results.

For some reason, Windows Defender always doubles the total number of files scanned.

I've tried this multiple times. If I scan 1 file, the result would say "2 files scanned".

The file type doesn't seem to even matter, as I've had this happen to JPEG, GIF, MP3, and MP4 files. I haven't tried TXT or DOC files yet, so maybe text documents are fine. PDF files I've scanned tend to have a high number of files for some reason (for example: 1 PDF could show up as 32 files scanned).

The scan results have shown "0 threats detected", so I've "Cut & Paste" the files from the Downloads folder to a flash drive. Strangely, when I use Windows Defender to scan the exact same files while they're on the flash drive, the total number of files in the scan results will now display correctly.

Why is it that a file scanned with Windows Defender will show double the number of files when it's scanned in the Downloads folder of the C:\ Drive, but will show the correct (single) total when it's on a USB drive?

Note:

1) The Windows 10 computer is part of a network. I don't know if the computer is set up to make duplicates to the OneDrive as a back-up, but even if that's the case, it doesn't make sense as the file I highlighted and scanned is in the Downloads folder, so it should be scanning a single file in one location.

2) Other than moving the files from the C:\ Downloads folder to the flash drive, I have not made any changes to the files at all.

- Unlucky Pete

 

[dvk01]

Have you got file history enabled in the backup settings on W10. If you have, then it is likely that Defender is scanning all backup copies of the file that also exist.
Scanning on a USB drive won't have file history enabled.

 

[Unlucky_Pete]

Sorry for the late reply. Some stuff happened which kept me away from the computer for awhile.

I checked the settings and it says file history is off, so it doesn't look like this is the cause.

On the off chance that all the previously scanned files were larger than expected, I went to the Microsoft website and saved a copy of their logo to test. I scanned that one small image with Windows Defender and the results still says "2 files scanned".

- Unlucky Pete