Do you know if a criminal stole your card information when you swiped at the ATM, or even a gas pump?
ATM skimming, or using a device to steal debit information, is on the rise and getting more sophisticated. Authorities discovered three ATM skimmers in gas stations in Ohio and one in a bank in Florida in the past month.
"ATM skimming is an over $2 billion problem globally," said Martin Bally, vice president and chief security office at Diebold Nixdorf, an ATM manufacturer.
Criminals are trying to cash in before more place switch over to chip cards, which skimmers currently do not work on. Right now, 45-50 percent of U.S. credit and debit transaction use the more secure chips instead of magnetic strips, according to the U.S. Payments Forum.
While older devices were relatively easy to spot, new devices are stashed deep inside.
"Now there's a skimmer that is literally as thin as…a credit card. And it slides into the slot and down. It's not even detectable," said Chris Hadnagy, the CEO of Social-Engineer, a cybersecurity training company. Hadnagy trains clients and law enforcement on the latest threats.
Hadnagy showed CNBC a skimmer he found for sale on the dark web, an area of the Internet that is anonymous and sometimes used for illicit activities. The device has Bluetooth capabilities.
"If you can get it in there [the ATM] and not be seen or found, you can walk up to the device later on, turn your phone on, connect to the Bluetooth wireless, download all the cards, act like you're pumping some gas and leave, and they would never know that it was you," he said.
An even more sophisticated skimming device lets criminals avoid going back to the ATM. These skimmers include SIM cards, which are used in cell phones.
"It calls to a server and downloads all the numbers to a file for them to obtain," Hadnagy said.
Even more concerning, Hadnagy says the new devices take very little effort to install. He showed CNBC websites on the dark web which post instructions.
The proliferation of skimmers has put the ATM industry on alert.
"Skimming has historically been the number one fraud issue for the ATM channel, so it's always been, on top of mind for our folks. The financial institutions generally do quite a bit in the way of countermeasures for skimming," said David Tente, executive director in the U.S. for ATMIA, the ATM industry trade group.
"The ATM operators …are doing as much as they can to try to fight this… It's an ongoing battle," Tente added.
ATM manufacturers are working on new solutions. Diebold Nixdorf came out with a machine which has you insert your card lengthwise instead of width wide.
"The way we approach it is by changing the direction and way and how we read the magnetic strip on the card. And that simple change has been able to defeat all static skimming devices," Diebold Nixdorf's Bally said.
There are currently 7,000 ATMs using the technology around the globe. At this time skimmers only work on cards inserted the normal way. However, Bally admits nothing is 100 percent.
Here is how to protect yourself:
On the Money airs on CNBC Saturday at 5:30 am ET, or check listings for air times in local markets.