Phone reset not only step to clearing personal info

HOUSTON (KTRK) -- Most of us can't live without our phone. And when a new one comes out, we trade or even sell the old one. But an investigation into sensitive information you may be leaving behind could serve as a wake-up call.

We store massive amounts of personal information onto our smart phones. And when you get rid of an old one, you may think you're wiping it clean first, but are you really? Not according to what our investigation uncovered.

They're not just for communication anymore. We use our phones for banking, shopping, storing personal photos and other very sensitive material. So when you get rid of an old phone, you reset it to delete that data, right? But is that enough?

"It's like on your computer when you delete a file, it's still there on your hard drive," computer forensics expert Colman Ryan said.

Ryan says depending on the device, it could take a lot more than a factory reset to clear it.

"The pictures are the honey pot for criminals. They can be recovered extremely easily," he said.

Marty Ewing had an old Android phone she wasn't using anymore.

"I thought I had cleared the phone, yes. In fact, I took it in to have it cleared," Ewing said.

Before she donated it, we wanted to see if any of her data could be retrieved.

So we took her phone, along with others that had been wiped back to factory settings. We took an iPhone, a Samsung Galaxy S2, a LG D-500, and a Nokia Windows phone and gave them to our expert.

"I used what the criminals would use. A $10 cable, and free resources from the Internet," Ryan said.

After hours of digging and retrieving data from the phones, the results were in and they were alarming.

"Deleted emails, texts, picture front and back of a credit card, W2s; other documents you wouldn't want anyone to get their hands on," Ryan said.

Out of our collection of factory reset Android phones, nearly 9,000 images were recovered. Hundreds of video files, audio files including music, and personal recordings. It's all valuable information criminals would love to get their hands on.

Ryan says before selling any Android phone, remove your SD card and SIM card. Also, digitally shred your data.

"There are free shredder programs out there like I-Shredder. Avast has a deletion or shred program," Ryan said.

The results on the iPhone were better. No data was uncovered.

"When you do a factory reset on an iPhone or iPad, you're good to go," Ryan said.

Ryan says newer Apple phones use hardware level encryption, and the encryption key is deleted as part of this process.

As for Ewing's old Android phone...

"There was actually a tax return. So you know on the tax return you have your Social, all the information you need for identity theft," Ryan said.

Ryan was able to retrieve 80 percent of the data she thought was cleared!

"Shocked, and it made me feel very nervous about ever getting a phone like that again," Ewing said.

Bottom line: Performing just a factory reset is not good enough for Androids -- use a shredding program. Experts also tell us if you encrypt your phone from day one, you'll be better able to wipe it clean.

For steps on doing that encryption and other tips on wiping your old phones properly, visit the Avast website or the Google app store.