“Shimming is the new skimming,” according to the Better Business Bureau.

The BBB is warning consumers of “shimming” scams, which are somewhat similar to skimming scams where scammers insert a device into an ATM in order to harvest people’s card information as they swipe.

Shimming involves placing a small, thin device with an embedded microchip and flash storage into the slot where you’d normally place your debit or credit card. When you insert your card into an ATM or any kind of card reader, the device copies and saves your payment information. Later, a scammer will return to the scene of the crime with a special card which is meant to store the stolen information, which typically includes your PIN and card number. Regardless, this type of scam gives the scammers all the information they need to make purchases using your accounts.

Unfortunately, these shimming scams are quite hard to spot, unless you’re paying close attention. As such, the best way to know if you’ve been the victim of a shimming scam is to regularly check your statements for suspicious transactions. If you notice a purchase that you didn’t authorize, use the customer service number on the back of your car to report the incident to the issuer. You should reach out to the card issuer, the bank, and the merchant if you notice an unauthorized payment.

If you notice your card getting stuck inside an ATM, or if a card reader is tighter than it should be, your card has likely been shimmed. Likewise, if you encounter any resistance inserting your card into any kind of reader, don’t try to push it through. Lastly, ATMs inside of banks are typically much safer than standalone ATMs on the street or ATMs in other establishments.