Hyatt has found malware on computers that process payments, and people who have stayed at a Hyatt hotel should check their bank statements for activity they don’t recognize.
The company said the problem has been fixed, but of the 627 Hyatt properties, 318 were affected by the security breach, BBC reports.
Hyatt is working with third-party security researchers to investigate the breach, and has set up a website to provide updates and more information to potentially affected users.
“We have taken steps to strengthen the security of our systems, and customers can feel confident using payment cards at Hyatt hotels worldwide,” Chuck Floyd, global president of operations for Hyatt said in a statement.
This isn’t the first large hotel chain to suffer a security breach this year.
In November, luxury chain Starwood hotels found malware on its sales systems in over 50 properties. And Trump Hotel Collection, the company managing Republican presidential hopeful Donald Trump’s luxury hotels, reported a security breach of payment data over the summer.