Transcript for Tips to Protect Your Credit Cards From Hackers
And "Gma" investigators this morning a consumer alert with new ways that hackers are stealing your credit card data. Maybe swiping your personal information out of your wallet or purse without you knowing it. Rebecca Jarvis turned to a star of the "Shark tank" to see how it works. Good morning. Reporter: Good morning. It is shocking how easy this work. Robert shows us how criminals using just a phone and an app can make off with your credit card information in a matter of seconds. In the race to score a deal this holiday season, you may be eyeing big discounts. But hackers may be eyeing you. And all it takes it a simple app. They're becoming more sophistica sophisticated. The last offer, $4 million. Reporte Robert is also a cyber security expert. And he shows "Gma" investigators how quickly your credit card information can be swiped. Simply by putting this near your purse, we're able to take your entire credit card information. Reporter: In a matter of seconds, he not only steals my credit card number, but my pin. My previous transactions pop up on his phone. He says this can happen with credit cards that have smart chips embedded. The wireless technology attached to the chips make it possible. Experts say it makes another level of security, and you can wave your card to pay. By the end of next year, 70% of credit cards are expected to have these chips. But experts say hackers are already outsmarting these smart cards. How you protect yourself? You have to read your entire credit card line by line. Reporter: He says check your credit card statement for small charges. They're getting sophisticated. I'm not going to buy a $5,000 item. Spend $20. Reporter: Those microcharges. We call that microfraud. Reporter: They are committed to investing in a system to protect millions of American who is use it every day. Products like this wallet are available to help shield your credit cards. It's got a little bit of a metal coating. If your credit card was in this, couldn't read anything. Reporter: And putting your credit cards in a metal sleeve or aluminum foil, yes, aluminum foil can protect you from situations like this one. Watch, my wallet right next to me. He puts his phone on top it of, showing how easy it is to steal my info again. Nowadays on the phone, reason together music, multi-tasking. This is simple. We staged this. But this is reality. Reporter: A problem he warns is not going away. The cards are becoming more smart. They contain more data, when they steal it, get more information. This is definitely becoming a bigger problem. Reporter: The most important thing to do if you believe this has happened, call your bank and credit card company immediately. You should not be responsible for fraudulent charges. But the low tech solution, aluminum foil, wrap it around your card. It's not the sexiest look. But it works. In this world, we have a lot of expensive ways to fix it, but the cheap way to. An easy fix. Unbelievable story. Thanks so much.
This transcript has been automatically generated and may not be 100% accurate.