system malware of android

my phone was not rooted i use it with a good anti virus software but there some problem get started
when ever i open any external link on my facebook app it open in its internal browser and then some add started comming....then after that any site of chrome without (HTTPS) format get redirected to any add even sites also get redirected....then aliexpress...and many other apps......

i factory restored my phone many time but nothing happned...........

then i rotted my phone , done twrp...

system malware of android

from Android Authority Forums http://ift.tt/2bJ7Vhm
via IFTTT