antivirus - Unable to remove malware

I have android tablet and every time i open a browser, any browser, it automatically opens pages with ads or making me download things. Obviously the tablet got a malware but i am not able to remove it. I installed Avast, Avira, Malwarbites, CCleaner but none of them was able to remove this malware. Any other ideas how to get rid of this malware? Usually in which location the viruses for android resides? In Windows most of them are in Temp folder but i am not very familiar with android.