Hi,
Thank you for the post.
According to your description, I understand you want to know whether “desktop.ini” file is a malware or not.
As far as I know, It depends. Some virus will create desktop.ini file on the folders, so people will have a mistake, think this file is a virus. Actually, desktop.ini is used to tell Windows how to display a folder. For example, enabling Thumbnail view creates a desktop.ini file in that folder which amongst other things, tells Windows to add an extra item to the View menu for that folder. Desktop.ini files are also used when you customize folders, change their icons etc. If you delete desktop.ini you will lose any customizations you have made to the folder. If you delete desktop.ini in a Windows system folder, it will just be recreated at the next restart.
Regards,
Nick Gu - MSFT