: Before attempting to open it, scan the file with a trusted security tool. Show or hide filename extensions on Mac - Apple Support
: If you are unsure of its origin, do not double-click it. Unrecognized file extensions can sometimes be used by ransomware to hide encrypted data. Apple.anom
: Open Terminal and type file followed by a space, then drag the file into the window. This uses a "magic test" to look at the signature bytes at the start of the file to determine its true format. : Before attempting to open it, scan the