ESET Mobile Security & Antivirus
Oh. it was Hiddak.AK Trojan on my android phone… that was causing full screen ad on home screen, whenever WiFi or Data connection was opened or whenever an new app was installed or uninstalled and installing new apps randomly without asking..
ESET Mobile Security & Antivirus was able to detect it by using Deep Scanning option..
It was hidden under the Service “ Android Communication Sync” .. watch out for this process in your phone