What end users are working with arbitrary files that they don’t know the identification of?
This entire use case seems to be one suited for servers handling user media.
This entire use case seems to be one suited for servers handling user media.
Of course on Windows the convention is to use the file extension, but on other platforms the convention is to look at the file contents
MacOS (that is, Finder) also looks at the extension. That has also been the case with any file manager I've used on Linux distros that I can recall.
Of course, it's arguably unlikely a virus scanner would opt for an ML-based approach, as they specifically need to be robust against adversarial inputs.
Several major players such as Norton, McAfee, and Symantec all at least claim to use AI/ML in their antivirus products.