Hyatt Hotels data is the latest to fall prey to hackers.
The company said Wednesday that it is investigating malware it found on computers used to process customers' payments, and Hyatt (H) is consulting with cyber security experts.
The data breach only affected properties managed by Hyatt and not franchise locations, the company said. As of Sept. 30, that included 318 properties.
Hyatt Hotels' current portfolio contains 627 properties in 52 countries.
"We have taken steps to strengthen the security of our systems, and customers can feel confident using payment cards at Hyatt hotels worldwide," the company posted on a website for updates about the hack.
A spokeswoman for the company said, "the malware has been identified on computers that operate the payment processing systems for Hyatt-managed locations, which is a subset of the total Hyatt properties."
Customers in the U.S. and Canada can contact Hyatt with questions at 1-877-218-3036 or +1-814-201-3665 from all other countries.
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Data breaches have become a prolific problem, and everything from children's selfies to troves of government personnel records have been targeted this year.
