Hyatt, Sheraton, Marriott and Westin hotels in 10 states and the District of Columbia may have been targeted by hackers for months.
According to the hotel operator HEI Hotels & Resorts, malware put into place in at least 20 locations may have collected names, card account numbers, card expiration dates and verification codes.
Data from customers may have been collected from early December, through late June. At some properties, HEI said, data collection may have begun as early as March 2015 at hotel locations where people bought food or drinks.
"The card number, the CVV and the expiration date - these records are literally being sold, and resold and resold on the illegal side of the internet," said Stu Sjouwerman, founder and CEO of Knowb4, a Clearwater cyber security firm.
Sjouwerman suggests travelers update laptops and smart phones before the trip - from home for increased protection from hackers.
And use a credit card, never debit, when checking into a hotel.
That's because fraudulent charges can not be disputed on your debit card.
If you stayed at Intercontinental Tampa Bay between March and June, monitor bank statements for unusual activity and freeze the accounts in question.
"No bad guy is going to be able to open an account in your name," said Sjouwerman. "Meaning identity theft is going to be a lot harder for the bad guys if you do that."
HEI said in a company release that "We are treating this matter as a top priority, and took steps to address and contain this incident promptly after it was discovered."
HEI said that once it found out about the problem it transitioned payment card processing to a stand-alone system that's completely separate from the rest of its network. It disabled the malware and is in the process of reconfiguring various components of its network and payment systems to make them more secure.
Escabor checked out of Intercontinental Tampay Bay Monday morning.
"Put me in a worried situation," said hotel guest Erick Escobar. "It's scary."
The company said it's continuing to cooperate with the law enforcement investigation and coordinating with banks and payment card companies.
Anyone who used a card at HEI hotels in the given time frame should review their account statements and look for discrepancies or unusual activity, both over the past several months and going forward, the company said. Customers who notice anything out of place should contact their credit or debit card issuer.
Customers may also visit www.heihotels.com/notice for additional information about the incident.
The company says the breach has been contained and customers can safely use cards at all of its properties.
Florida hotels affected include:
- Boca Raton Marriott at Boca Center - dates affected: 3/1/2015-6/7/2015 and 12/15/2015-4/11/2016
- Intercontinental Tampa Bay - dates affected: 3/21/16-6/15/2016
- Royal Palm South Beach Miami - dates affected: 12/23/2015-6/6/2016
- Westin Fort Lauderdale - dates affected: 1/29/2016-4/13/2016
For the full list of hotels affected click here .