It's been quite some time since I last used Android, but following the untimely death of my old "roaming" phone while travelling in India, I've just ended up buying myself a Micromax Q338. This runs a Micromax modified version of Android 5.1 Lollipop
After uninstalling or disabling a few of the annoying apps it shipped with, I'm still faced with one issue - adverts showing up as notifications on the lock screen, which seem to turn up when / just after connected to the internet. If I touch and hold on them, they show as being from System Update, as shown here:
As far as I can tell, System Update is an official component, and not a third party app. As such, I don't think I can/should uninstall it. I also can't find System Update under Settings / Sound & notification / Notification / App notification, so I can't apparently disable them that way.
So, how do I stop System Update popping up adverts on the lock screen when there is / has been internet?