Global hotel chain Hyatt Hotels (NYSE:H.) warned customers that the computer system it uses to process payments has been breached.
The Chicago-based firm said it has found malicious software in the system, increasing the chances of hackers obtaining credit card numbers or other personal information.
A spokesperson for Hyatt refused to comment on whether any customer data had been stolen.
The malware was found at the end of last month and the investigation is still ongoing, with outside experts brought in to help improve the firm’s security.
Hyatt owns, manages or franchises 627 properties in 52 countries with the malware found on computers that process payments for the hotels that it manages, though it is not known how many.
It’s one of a string of cyber-attacks on hotel companies after Starwood Hotels & Resorts Worldwide (NYSE:HOT) and Hilton Worldwide Holdings (NYSE:HLT), both reported similar bugs in their systems last month.
Hyatt will provide updates on its website, but added that customers “can feel confident” using credit and debit cards at its hotels.