Report finds that factory reset on Android devices don’t wipe all the data

If you thought factory resetting your smartphone before selling it would wipe all the data on it, then this new report debunks that idea. Security software firm Avast bought 20 different Android phones on eBay and used data-recovery tools on all of them. They were able to uncover 40,000 photos (over 1,500 family photos and around 250 photos of someone’s “manhood”), 250 contacts with names and addresses, loan applications, 750 emails, and even a completed sexual harassment course.

When wiping files on a device, it doesn’t erase the data itself. The software that manages your data will erase the index information for the file and then marks those bits as ready to be overwritten with new data. However, it doesn’t guarantee the data will be gone after that. If you use the right recovery tools, you can still access them.

Chris Bross, CTO for data-recovery service Drivesavers, suggests you factory reset a device and then fill the phone’s storage with benign data so you’ll be overwriting and resetting the NAND flash on the device, and then you wipe it again. However, this still isn’t a guarantee. There are disk management and security tools out on the market that can permanently delete data but that process would take longer than a normal hard reset.

For detailed information of how to securely and completely wipe your device, check out CNet's tutorial here.

Source: Mashable