@DanHulme Don't hit me straight away, but which end-user would do that – and download 19GB data for it even? IMHO that's even "dark gray area" if you'd take in power-users.
Hm, should we make a generic "my phone is (suddenly) doing [weird things]" question? This is at least the 3rd question on "how to figure out which app does X on my device" in the past 3 days: My phone is sending messages to international number
I've just put a hint inside the malware tag-wiki, so the corresponding answers are easier to find (figured that the best matching tag, as it's the most used context).