Chinese message always shows up on the home screen.
A Chinese message always pops up on the homescreen for few seconds. I have managed to take a screenshot, but don't know how to attach it here. Please follow link for the snapshot
That's an app connecting to a server to get an instruction by the looks of it. I would look for folders in storage/android that had similar words and choose to delete the app contained in it or not.
Does the same message appear while your device is rebooted in safe mode? If not then this points to a third party application and will be difficult to test from my end. I would then suggest looking into what @Viridis mentioned.