Latest ATM scam is heading to the U.S.

Using special devices to "skim" ATM data is an old trick, but advances in the technology is making them more dangerous than ever.

The European ATM Security Team is warning about new skimmers that are almost impossible to detect with the naked eye, according to Krebs on Security. Thanks to a slimmed-down profile, the devices sit within the throat of an ATM card slot, capturing data when a consumer slides her card inside. A spy camera then tapes the customer as she enters her PIN number on the keypad.

Some older skimmers fit on top of the card-reader slot, obscuring the slot's flashing light and generally making them easier to detect for consumers on the lookout. Several of the newer, almost invisible types have been found in European ATMs, although criminals are now being thwarted in those countries thanks to the rollout of so-called "chip and PIN" technology, which makes it harder to duplicate stolen cards. Because the U.S. is one of the last countries to move to the chip-and-PIN cards, the new skimmers are migrating the U.S., the report notes.

"In countries where the ATM [chip-and-PIN] rollout has been completed most losses have migrated away from Europe and are mainly seen in the USA, Asia-Pacific and Latin America," the report said, according to Krebs.

The next-generation of card skimmers are "getting harder to detect," the report added. Officials at the European ATM Security Team weren't immediately available for comment.

But there are ways to protect yourself, according to Krebs on Security's Brian Krebs. The simplest way to thwart thieves is to cover the PIN pad when entering the numbers, obscuring the code from any potential spy camera lurking nearby. That's a precaution that not many consumers take, Krebs notes.

If you visit an ATM that appears suspicious, don't use it.

"Consumers should look for signs of tampering on the ATM, such as damage or alteration to the card reader, unusual looking keys or overlays on the keyboard, or even devices on the door to the ATM location that could be used to capture magnetic stripe data," Eddie Schwartz, chair of the Cybersecurity Task Force of information-security association ISACA, said in an email.

Some ATMs in tourist areas or in outdoor locations are popular with skimmers because they are easier to fit with the devices without people noticing, according to Wired. It may be safer to rely on ATMs within a bank lobby, given that employees are generally nearby, making it tougher for thieves to install the devices.

"It's important for consumers to use ATMs that are under constant camera surveillance and that are not in isolated areas where they can be tampered with easily by criminals," Schwartz noted.

On top of that, make sure you are keeping up with security precautions for credit-card or debit-card fraud, such as checking your bank statements and reporting any authorized charges to your bank.