Many mobile device users rely on simply deleting the private information on the storage card of the phone before selling it, in order to ensure that sensitive details are not passed to the new owner. However, items are stored persistently, and unless they are corrupted through overwrite action, they can be recovered.
Avast carried out an experiment with 20 Android phones purchased through eBay, and then tried to find out how much of the deleted information could be retrieved.
The results showed that a numerous amount of items belonging to the previous owners could be recovered by using a mainstream utility.
According to their report, they managed to bring back more than 40,000 photos, and learned about over 1,000 Google searches, more than 750 email and text messages and over 250 contact names and email addresses.
By putting together these bits and pieces, cybercriminals can learn important details about the potential victim and start targeted phishing campaigns with a high rate of success, which could bring them a pretty income.
Blackmailing activities can also be deployed by the criminals, as Avast says that more than 750 of the images retrieved were with women in various stages of nakedness.
Among their findings were the identities of four previous owners, which can also be leveraged to conduct nefarious activities against them.
“They can use this information to watch people’s every move, exploit their strange fetishes, open credit cards in their name, or even continue what they started by further selling their personal information online,” says Jude McColgan in a blog post.
All this, and more, was discovered on just 20 mobile phones, but the company notes that more than 80,000 smartphones are available for purchase online on a daily basis.
There are plenty of tools that can scan a storage device and get back the deleted information. Alternatively, there are many utilities to perform multiple overwrite passes on a storage device in order to make sure that any deleted files are corrupted and cannot be brought back to life.
Many users have the wrong impression that a reset to factory defaults is all they need in order to ensure that the data is lost forever. Unfortunately, nothing is further from the truth.
A search on Google Play for tools designed to erase the storage cards securely should reveal numerous results, but our recommendation is to pick an app from a reputable vendor.
If all the data is saved on a removable SD card, the options extend to desktop programs too, as these solutions provide multiple choices, Recuva from Piriform offering both recover and wipe options.