White Lodging, the company that maintains Hilton, Marriott, Sheraton and Westin hotel franchises, has apparently suffered a data breach that exposed guests' credit and debit card information in 2013, the KrebsOnSecurity blog reported.
"An investigation is in progress, and we will provide meaningful information as soon as it becomes available," White Lodging said in a statement.
White Lodging is just the latest American business to investigate a security breach.
Late last year, Target's systems were hacked. That breach, which remains under investigation, could be the largest breach in U.S. retail history. It affected up to 110 million customers, including 40 million credit and debit cards and up to 70 million customers' personal information.
The retailer discovered the breach in mid-December, notified customers several days later, and launched an investigation with the help of a private security firm and law enforcement.
Since Target's disclosure, high-end retailer Neiman Marcus announced over 1 million customer cards were compromised in a breach last summer.
And last month, crafts retailer Michaels said its systems may have been breached.
It isn't immediately clear if these possible attacks were related. Security experts have warned it is likely other companies were targeted by the hackers who hit Target.