... and let's not forget about the adult movie

Feb 24, 2016 20:43 GMT  ·  By
People often forget to wipe their phones when selling them, leaving personal data behind
   People often forget to wipe their phones when selling them, leaving personal data behind

People often forget to wipe personal data from smartphones they sell, leaving behind files that reveal more information about themselves than they previously thought.

Avast, a well-known cyber-security vendor of desktop and mobile security products, carried out a simple experiment. Its researchers bought five phones from various pawn shops in New York, Paris, Barcelona and Berlin.

Using regular data recovery software, freely available online, the researchers scanned the devices' storage and recovered details on the phones' previous owners.

2,000 files left behind, 200 of them are adult-themed photos

The results yielded over 2,000 files that should have never been left behind since they exposed the users to fraud or unwanted privacy intrusions.

The recovered data included more than 1,200 personal photos, 300 email and text messages, three invoices, and even a work contract. Of the 1,200 photos, 149 were photos of the previous owners' children, and 200 included adult content.

On top of these, researchers also recovered full details on the identity of two of the previous owners, one adult video, and 260 Google searches, of which 170 were for adult material.

Android's factory reset feature got better

Two years earlier, the company conducted a similar study on a larger batch of phones, which found over 40,000 files of a similar nature, meaning the problem is nothing new.

Back then, Avast researchers discovered that the factory reset function in older Android OS versions was not actually removing all the proper information. But researchers are now saying that Android has a much powerful factory reset function, which should eliminate all these issues.

While it is understandable that some pawn shop smartphones may not come from "legitimate" sources, being either stolen or found on the street, researchers say that this is not always the case, and often, actual phone owners leave a lot of traces behind as well.

Users that sell or pawn their devices should take this experiment as a warning and reset their Android phones, and then follow through by wiping the device's storage clean. For this latter operation, tools like the Avast Anti-Theft Android app can come in handy.