I am using Samsung Galaxy Core Prime. Everything has been running smooth except the fact that for sometime I'm facing a strange problem of touch screen as well as touch button (Back button) at the same time. For example, when I chat using either Facebook Messenger or WhatsApp, sometimes I observe while typing in the keys the screen behaves abnormally i.e. if I try to erase a character there appears a new line or so. The keys don't respond.
At the moment, if I touch the Back button instead of going back to the previous app a new app appears (say Google+ here). Moreover, if I try to swipe down to go to the settings at the same time it pops down partially and disappears. The touch screen doesn't work entirely for a while. The problem vanishes automatically after a while, but very annoying as it occurs repeatedly.
I have 360 Security Antivirus installed and scanning shows no viruses either. What is the cause of this problem?