Someone purchased a Google Pixel 4a from a classified ads website, but when they received the device, it looked a bit odd. On the outside, it looked like an ordinary Google Pixel 4 branded device, but the software didn’t exactly feel the same.

The original story was published by the Motherboard. The smartphone didn’t even have developer options, the option seemed to have been hidden, and the bootloader was also locked. As it turns out, this device wasn’t originally ‘sold’ by Google, but the US Federal Bureau of Investigation, or FBI. The device came with a custom ROM called ArcaneOS and had a messaging software pre-installed called “ANOM” that was also made by the FBI to catch criminals discussing and planning criminal activities.

An XDA-Developers member has also posted on the Google Pixel 4a forums seeking for help to remove the ArcaneOS back in May. Another user on a German Android forum called Android-Hilfe had posted a similar problem, but they had a Google Pixel 3a.

Google Pixel 4a used by FBI 1

The device’s settings screen (Image Credit: Motherboard)

ArcaneOS lacked any Google Mobile Services which also meant that it didn’t have a Play Store, and the Developer Options in settings was hidden. The bootloader locked, which is only possible “because Pixel phones support running alternative operating systems on a locked bootloader so long as one adds their own signing key to the Android Verified Boot (AVB) process.” via XDA-Developers.

Google Pixel 4a used by FBI 2

ANON login screen (Image Credit: Motherboard)

After the users have found out that their newly purchased devices are nothing more than a fairly expensive paper weight, they went on to sell the devices and got rid of them. This could explain how the Vice got their hands on it, and how they managed to publish this story. The Vice has also discovered that the phone’s software can log communications for evidence of criminal activity, which is why the FBI has only sold this very device to criminals.

Google Pixel 4a used by FBI 3

PIN entry screen (Image Credit: Motherboard)

When the device is unlocked using a normal PIN code, the home screen shows applications such as Netflix, Facebook and Tinder, but there’s a catch. None of the apps open or work at all, they’re only there for the show. Unlocking the Pixel with an entirely different PIN reveals icons for a calculator, clock and the device’s settings. Tapping on the calculator application opens the ANOM “encrypted” messaging service that logs all the communications and sends it back to the FBI. After the ANOM messaging service was publicly disclosed, a lot of criminals started selling and getting rid of the devices, which is likely how the XDA members and other people got their hands on these special devices.

If you would like to read the full story on this interesting topic, you can read more on Vice.