Do you remember yesterday info about four more gaps in Snapragon drivers?
That’s nice because Google announced that solution for this kind of danger is in use…
Verify Apps was created just for this type of problems and is activ in devices with Android 4.2 – owners of older versions of OS can manualy turn it on in Google Settings app in security tab.
But still, until patch will be avaible I would not install apps from outside of Googlpe Play.

Source: Android Authority