Can Malware damage to the files existing on the host?

[Layback Bear]

Kurdman all you have to understand is their is no exact cut off line on infection.
That is why their is a over lap on what a anti virus and a anti malware programs find.
Different branded anti virus or anti malware programs have different definition that change all the time.
Giving you a exact answer why the branded program calls something a malware and another branded program calls it something else can't be done as far as I know.
It is constantly changing. That is one of the reason we use more than one program to fight infection which ever side of the line (malware|virus) they are on at any certain time.

To truly understand infection you will have to read volumes of books and make it a life profession.
Please just choose a anti virus program and a anti malware program that you want to try.