Internet Explorer Processes - Mime Sniffing Safety Feature - explorer.exe
Information
This policy setting determines whether Internet Explorer MIME sniffing will prevent promotion of a file of one type to a more dangerous file type. If you enable this policy setting, MIME sniffing will never promote a file of one type to a more dangerous file type. If you disable this policy setting, Internet Explorer processes will allow a MIME sniff promoting a file of one type to a more dangerous file type. If you do not configure this policy setting, MIME sniffing will never promote a file of one type to a more dangerous file type.
Solution
Policy Path: Windows Components\Internet Explorer\Security Features\Mime Sniffing Safety Feature Policy Setting Name: Internet Explorer Processes