(WSYR-TV) — Skimming devices have been installed by suspected scammers in at least five New York Walmart stores over the last week, local police departments confirmed to Nexstar’s WSYR.

Investigations have been opened after devices were found in stores in Granby, East Syracuse, Camillus, Auburn and Oswego.

In each case, the machine was installed on Sunday, July 2, and discovered on Wednesday, July 5.

Surveillance images released by police in Auburn, Camillus, and Oswego show the same three people either entering the store or tampering with the credit card terminal.

They’re accused of adding a skimming device, which is a cover that looks just like the machine, but it steals a customer’s credit card information when the card is inserted.

“It’s been called ‘gutsy’ to put those devices where they were located, because it’s a very public area,” said FBI Supervisory Special Agent Samantha Baltzersen.

Skimmers typically attack the most vulnerable cards: cards requiring the swipe of a magnetic strip. Advanced skimmers can even steal information from the newer chip cards, but it’s less frequent.

Police in New York haven’t determined how advanced the skimmers are used in this string.

Police also haven’t received reports of any victims in the Walmart skimming cases yet, but people who used their credit cards over those four days at the impacted Walmarts should be on high alert for fraudulent charges.

“They’ll try to hit where they see weaknesses in the system or weaknesses in the locations,” said Debbie Cobb, a senior director of product management at FICO.

Cobb said anytime you see a credit card payment terminal that looks like it may have been tampered with or has something attached to it, you should exercise caution and avoid using it to pay.

FICO shared more advice on what to look for and how to protect yourself:

What should consumers look out for?

• When consumers go to make a payment, they should take a close look at the part of the device where they insert their card. If anything about it seems loose or looks disconnected from the actual system, that should be a red flag. If something looks suspicious, you should not complete the payment.
• Recent advances in technology have enabled fraudsters to have more sophisticated and harder to detect card skimming technology. For example, fraudsters will install microscopic cameras at the top of ATMs or other points of sale that look like a small pinhole. Consumers should keep an eye out for any small holes or disjointed parts of the payment system that might be capturing their confidential information. Fraudsters will use these cameras to observe your PIN code, so it is very important to make a habit of completely covering the PIN pad when entering your information. 

How can consumers protect themselves from card skimming?

• Consumers should always look for ways to use the most secure payment mechanism. Generally, the weakest method of payment is using the magnetic stripe on your card. If your card has a chip or supports contactless payments, those payments methods are more secure. If you are in a situation where you have to use the magnetic stripe, take a moment to heighten your awareness and make sure to shield your PIN code. 
• It is important to set up alerting with your financial institutions. Many banks enable their customers to set up real-time alerts that will notify any suspicious transactions or certain transaction types or characteristics such as exceeding a certain dollar amount. By taking advantage of the technology that your financial institution offers, consumers can better protect their funds.