Can't Disable Chinese apps on Samsung Note 3

A relative picked picked up a 'Samsung Galaxy Note 3 SM-N9006' on his trip to China. It was misbehaving so I did a reset. When it booted I noticed a few Chinese icons on the Home screen. Opening them takes me to a bunch of Chinese porn sites! I removed the icons and an app called ChatOn but now I have 4 new Chinese apps that have been downloaded and started automatically! When I Stop and Disable them they come back. So what do I do? I don't trust the device as it is. What are my choices? Root it and try to clean it that way? I don't even know how they are being downloaded. Can I trust the factory ROM at all? Install a different ROM on it? Thanks. ---------- Device Info: Samsung Galaxy Note 3 SM-N9006 Android 4.4.2 Baseband: MT6582 Build: JSS15J.N9006ZCUBMI5