If you’ve traveled within the last year, you could have stayed at several hotels that were targeted by hackers.

An undisclosed number of people who used credit cards at 20 Hyatt, Sheraton, Marriott, Westin and other hotels in 10 states and the District of Columbia may have had their cards compromised after the hotel payment systems were hacked.

HEI Hotels & Resorts, which operates just under 60 hotels and resorts under a variety of brands, said that after being notified by its credit card processor of a potential breach, it conducted an internal investigation that found malware on its payment processing systems at the 20 hotels.

>> Read more trending stories  

The malware was designed to capture debit and credit card information such as names, card account numbers, card expiration dates and verification codes, according to a release.

The hack potentially affected cards used at point of sale terminals, such as those at the hotels’ restaurants and stores, between December 2015 and June 2016. Systems at a few of the affected locations were found to have been infected with the malware as early as March 2015.

Retailers and other companies that deal with large numbers of credit cards have become popular targets for hackers looking to make a quick buck by collecting and selling the information on the internet in bulk.

Among the hotel chains, Hilton Worldwide, Trump Hotel Collection and Starwood Hotels & Resorts have all confirmed POS system breaches within the past year or so.

The impacted HEI Hotels & Resorts included locations in Florida, Texas, Vermont, Illinois, Virginia, California, Tennessee, Colorado, the District of Columbia and Minnesota.

Customers who notice anything out of place should contact their card issuer.