Mobile OSs 1 - Android Privacy Features Review


Author: InvisibleUser Team

Learn how to reach optimal mobile OS privacy. In this article, we will focus on the most popular system, so we will review Android privacy features.

Since mid-2018, the world uses mobile devices more than desktop PCs (including laptops) computers. That makes mobile OS privacy even more important than privacy on the desktop platform.

In this and the following posts, we will introduce mobile OSs. They are widely used and it is therefore important to bring privacy to your handset. In this series, we will review the OSs iOS, Android, LineageOS and other custom ROMs with privacy features in mind.

This article is part of a series, all 6 parts are here:

Android Popularity and Security

We only mention Android, because it is based on Linux kernel. The OS section of this guide is mainly designed to help you find a secure desktop OS that is good for privacy. Android privacy features are, however, such a disaster that we must include the OS in his guide.

Popularity of Android

Android is the most used mobile OS at the moment. It was developed by Android Inc. in 2007, but was bought by Google soon after. It is now maintained by Google LLC and runs on roughly 73% of smartphones/tablets.

The main reasons for that are that it is easily modified to run on smartphones with different hardware configurations, booth high-end and low-end devices. Android is also very user-friendly and intuitive, so plenty of people like it. Google developed it together with the Linux community. Therefore, the core part of Android, the Android Open Source Project (AOSP), is open-source. Google added proprietary software on top of the core part. The proprietary components come pre-installed on the devices you can buy. Additionally, apps can be installed from Google’s Play Store. The Play Store is quite lucrative for the company, since 30% of the proceeds go directly to Google.

In the beginning, Android was largely based on the Linux kernel, but there have been significant adjustments to the software: The different processor architectures, amd64 on desktop and arm64 on mobile, touchscreens and many other differences made it necessary for Google to develop Android in another direction. Most changes were necessary, because it is an OS for embedded systems and smart devices. That means that it runs on a specialised device, instead of on a computer.

Other than smartphones, there are many more devices that need custom designed firmware. Such systems are:

  • Set-top boxes
  • Smart TVs
  • Routers
  • Hardware firewalls
  • Music workstations
  • Tone generator modules
  • Digital pianos
  • Smartwatches
  • Cameras
  • Navigation systems, etc.

Versions of Android itself are available for smart TVs (Android TV), smartwatches (Wear OS), cameras (Camera API), cars (Android Auto) and even refrigerators?!? (smart fridges with Android Things). Originally, the goal of Android development was to create a camera OS, but the developers found that the digital camera market was too small and expanded. The low cost and customisation options make Android and other Linux-based OSs ideal for manufacturers.

In the media, it is often reported that Android could be seen as a Linux distro, but in 2019, Android is far away from Linux’ original code. Even the Linux Foundation likes to call it part of Linux, but we disagree. Essential parts like the GNU C Library are missing in Android. There have been attempts to bring the open-source part of Android, the Android Open Source Project, closer to the current Linux kernel, but Google is not very cooperative. They do not offer much assistance, when it comes to integrating their adjustments into the main branch of the Linux kernel. GitHub mirror

Android Security

Android runs apps in a sandbox, so they are isolated. That makes it fairly secure and resilient to attacks, because the damage malware can do is therefore limited. Android viruses exist and there are more every day, however. A big problem with Android is that it gives apps too many permissions.

Why does a single-player game need to read your call log, record audio and write SMS? Why does a cloud storage app need access to contacts, read the clipboard and use haptic feedback? Giving apps far too many permissions makes Android less secure.

If you turn their permissions off, you will notice that the apps work just normally. All those permissions are in no way needed for the thing that the apps are supposed to do. The system security is reduced for no good reason. That said, the “security through isolation” is still in effect.

Another thing that makes Android in general a fairly safe OS is that it uses Linux kernel security modules like SELinux (Security Enhanced Linux).

Some very greedy apps just ignore your permission settings: We have observed that Google Maps will turn on fine location tracking permissions, even if you have turned them off before and it does not ask for consent. This permission is of course needed for Google Maps to function, but you should know that you cannot disable tracking while you are not using the app. Google Maps completely ignores your settings. There are over 1,000 apps that do the same.

Android Privacy Features

Android Privacy

Now to the negative part. Android privacy features are a disaster!

As you might have expected from a system made by Google: It spies on you!

That is done by the internet giant, under the guise of an open-source OS. Google has the ability to delete or install apps and change settings on your device via remote access. Google forces its own services on manufacturers, they did this for example with their geolocation detection service and the entire suite of Google apps. Their “”Mobile Application Distribution Agreement” (MADA)” states that “”Devices may only be distributed if all Google Applications [ … ] are pre-installed on the Device”.

You will now understand that it is not a free system. We would like to quote GNU here:

“It [the Play Store app] also has a back door with which Google can forcibly install or deinstall apps. (This probably makes it a universal back door, though that is not proved.)”GNU Website

It is theoretically possible to use an Android device without a Google account, but that limits you to very basic functions of the phone and you can only download apps from the internet or F-Droid, instead of the Play Store. F-Droid is an open-source app store for Android.

When you are using the OS with a Google account, the massive data collection we described in “Why Privacy is important” will take place. That includes your contacts and a list of places where you have been while the phone was in your pocket and your current location. Even if you do without a Google account, there are pre-installed Google applications that cannot be removed without root access which the user does not have, normally. To get root access, you have to root the phone and that will often end your warranty.

Such Google apps can do almost anything on your device: Uploading photos from your Google storage or requesting your email address and information from your Google+ profile, as well as Facebook and Twitter accounts. If you do not give permission to track you via GPS, this will simply be done through your WiFi connection (source).

There has been a study conducted by Digital Content Next. It reveals that even without moving, your device will transmit your location 340 times within 24 hours. 35% of that data is sent to Google servers. When you are moving and changing your location, the frequency of data transmission will increase even more.

Why do people spend 700€ on Google’s surveillance tools? Please do not use SpyDroid, even if the code name of the OS sounds tasty, like “Ice Cream Sandwich” or “Jelly Bean”!

The official Android site that explains how awesome Android privacy features are implemented is a joke.

Google Play Protect

Something we definitely recommend is disabling Google Play Protect. It is a service that scans for malware. The areas it scans are the Play Store, but also your device’s external storage, internal storage and browser. Play Protect is supposed to warn you if you visit websites known for malware, but that also lets Google know about your browsing history. The function most people use it for is scanning their device for malware. That is completely unnecessary if you only download from trustworthy websites and the Play Store. Google already scanned the apps on the Play Store anyway, so it does not help to let them scan your device too.

The only thing it does is giving Google access to your installed software. While Play Protect makes its way through your files, it can read all the memory and not just the section where apps are normally stored. Play Protect is not even effective and fails in many situations. We will illustrate that with a case study. Just look at the example of the ExpensiveWall malware. This Trojan Horse was hidden in many apps, including “Lovely Wallpaper”, from which it got its name. It was not detected. Instead of blocking it, Play Protect ignored the malware and it was installed on up to 20 million Android devices.

Further reading

We highly recommend 2 articles on whether Android is actually “free software” like Google pretends. One is from The Guardian and the other one is from the GNU Project. The latter much more detailed and of very high quality. It illustrates how compromised Android is, how much Google limits users’ freedom and that Android privacy features are lacking.

The Android Open Source Project can be found on GitHub (mirror) and the official source code is provided by Google. The most important part of Android, the Platform System Core source code is here on GitHub and here (official). On Android Developer is an overview over the platform architecture.


FreeDOS Guide and lesser-known OSs


Mobile OSs 2 - iOS Privacy Features Review