9241.emix infected file, what is this exactly?

There are no known Windows-like Viruses in the wild that self replicate and affect macOS, because of the underling UNIX  Foundation and Permission Limitation. 

The Only thing this Antivirus software is protecting is the Bank Account of the Developers and for zero return to the User aside from the problems this software creates.

The The Built in Security  is all that is required to protect the computer.

Any Third Party Applications that will interfere with the normal operation of the OS, alter, modify, remove or delete or attempt to do so is an invitation for disaster and may require a Reinstallation of the OS.

This includes AntiVirus, Disk Cleaners, Disk Optimizes, UnInstaller etc.

This will include CleanMyMac 

This will include BitDefender 

This will included Norton Antivirus

Sophos Av Software

Intego AntiVirus

3rd party virus scanners are completely worthless on a Mac. All they will do is consume resources and potentially damage important files when they throw false positives.

There are no known viruses that can affect macOS.

Get rid of it before it does real damage by quarantining or deleting something critical.

+1

.emlx is an eMail file.

What makes you think it's "infected"?

From what I have read the are various applications that may use this file format but no specific Appliation has been identified as the Sole User of this file type.