Mobile Fundamentals · Mobile Operating Systems · Lesson 5 of 5

Challenge: The Downloaded Game

Figure out what a sideloaded game could reach on a teen's phone.

A game from a website

Your neighbor Tom asks for help. His daughter Ava, who is 14, installed a free game on her Android phone. She didn't get it from Google Play. A video she watched linked to a website, and she downloaded the game from there.

Tom wants to understand what happened and whether her other apps, including her banking app and her messages, are at risk. Ava is happy to show you her phone and walk you through what she did. She says it took a couple of extra taps to get the game installed, but she can't remember what they were.

When you look in Settings, you see that her web browser has been given a special permission. Without it, the phone would never have installed an app straight from a website. Tom has never heard of it.

Look inside

The downloaded file is still in Ava's Downloads folder. A friend of yours who studies security offers to look at it on a laptop before anyone decides anything. He opens it with an ordinary unzip tool.

Inside is a list of files and folders. Tom mainly wants to know what the game asks to access, such as contacts, location or the microphone, so he asks your friend which file to look at.

Two prompts

The package shows the game wants contacts and location. Sure enough, when Ava opens the game, it asks for both.

The game is a simple puzzle where you slide colored tiles around a board. There's no map, no friends list and no way to invite anyone. Ava wants to keep playing, but she doesn't want to hand over more than she has to.

Could it reach the bank app?

Ava has uninstalled the game, but Tom is still worried. He asks whether a bad app like that could have read her banking app's data or her messages while it was installed.

You check her phone. It runs the normal software it came with, and nothing has been modified. Then Tom mentions his own older phone, which a friend rooted for him years ago so he could change some settings. He wonders if the answer is different for that one.