General question - Malware or virus threat

Motim · 27 Mar 2017

Hello,
On turning-on my computer, first thing is updating antivirus (AVG), scan computer, and if I download anything, first is to scan it with the antivirus.
Recently I attached an external usb disk (new, clean and empty) and to free some disk space moved many files to the external disk, most of the files are program installation files which are installed on the computer.
Then I ran a scan on the external disk, and the scan found some threat and cleaned it.
My question is (just for knowledge), how is it possible same file on the computer scanned clean and on the external disk found some threat ?
Answers will be appreciated.
Thanks
Motim

Caledon Ken · 27 Mar 2017

Hi Motim.

From my experience not all AV scanners scan every single file on a computer unless you so direct. Especially if you use two or more drives.

You can imagine how long a full, every file every where, scan would take on each boot. As such the different vendors scan the high risk areas. Some products even allow you to set which files can be ignored.

I would open AVG and see where it normally scans. You also likely have a "Custom" scan. Open it and you likely can likely set it for everywhere, every file.

Ken