No, it wont upload anything, it is a system sandbox for PNG, JPG/JPEG, GIF, ICO, WEBP, BMP, and WBMP format image files. Technically it isnt an antivirus by any means, but I guess for the masses it is easier to understand that this is a feature that will make Galaxy users safer. "The Message Guard feature currently works on Samsung Messages and Messages by Google, and will eventually be made available to undisclosed third-party messaging apps via a software update “at a later date.” Message Guard doesn’t need to be activated by the user and runs “silently and largely invisibly in the background,” according to Samsung." It should work with any protocol as long as Samsung Messages and Messages by Google are used.