Android has a built-in security service, called Verify Apps, that scans apps for malware as you install them. It operates on apps you didn’t download from the ay store (which have already been scanned prior to downloading).
That leaves a significant hole. at if an app is clean, thus passes the check, then downloads a bad payload? If you don’t regularly scan for malware on already-installed apps, you’re still vulnerable. Hence the need for security apps like okout, which comes pre-installed on so many phones.
A post on the official Android blog today announced a solution: continual Verify Apps scanning. This should make sideloading a little bit safer, give you a little more confidence about downloading from the ay store, too. Still, exercise caution with what you download install, pay attention to the permissions requested by an app!
There’s no word on exactly when this update will roll out, but it can’t come soon enough.