A startling discovery from security firm Avast Software will make you reconsider selling your old smartphone: Even after performing a factory reset, your browsing history, photos, and text messages can still live on the device.
In a qualitative study released Tuesday, Avast detailed how it purchased 20 used smartphones, including iPhone and Android models, from eBay about a month ago, wiping them using the default settings provided by the manufacturer, operating system, or carrier. Even after taking these measures, Avast recovered photos, past search queries, social media information, contact information, and much more. In four of those instances, the firm could trace the identity of the phones' previous owners. In other situations, it was able to stitch together profiles based on the data left behind (an actual example: a model talking about her body issues relating to weight gain on Facebook).
"A factory reset or clean wipe isn't getting rid of all the information," president of mobile Jude McColgan told Fast Company. Depending on the type of wipe, the process could overwrite references to the data, so that it isn't be readily accessible, but the files can still reside on the device.
Some of the examples of data left behind include nude selfies, lingerie shots, anime porn, searches about psychotic medication, and even a completed loan application. In total, Avast said it uncovered more than:
- 40,000 photos
- 1,500 family photos of children
- 750 photos of women in various stages of undress
- 250 photos of male nude selfies
- 1,000 Google searches
- 750 emails and text messages
- 250 contact names and email addresses
Of the 20 smartphones, one had installed a competitor's security software. That device, McColgan pointed out, had the most personal information intact. (Of course, the point of the study is to highlight the effectiveness of Avast's software, which the firm says overwrites all files permanently.)
"Just be careful," he cautioned smartphone owners. "Understand what you're carrying on your phone, and use good tools."