I've got a Note 4 and have had Marshmallow(6.0.1) for a month or so. Over the last couple of days I've had a notification pop up just above the app dock. It's a black oval with white text. I have no idea what it says as it's some kind of Asian language, everything else is still in English. Occasionally it will indicate something in ms. It doesn't stay on the screen long enough to get a screen shot. Virus and malware scans don't find anything. If it's a setting, I have no idea what to look for to stop it. Any help is greatly appreciated!