The chain's hotels in the US are the latest to be hit by series of security breaches in the hospitality industry
The US Hyatt Hotel chain has said that its payment processing system was infected with credit-card-stealing malware in an attack discovered three weeks ago, the latest in a series of breaches at hospitality firms.
Company spokeswoman Stephanie Sheppard said that the attack was discovered on 30 November.
She did not say if the attackers succeeded in stealing payment card numbers, how long its network was infected or how many of the chain's 627 hotels were affected.
"Customers should review their payment-card account statements closely and report any unauthorized charges to their card issuer immediately," she said.
Hyatt, controlled by the billionaire Pritzker family, is the fourth major hotel operator to warn of a breach since October.
Other hotel groups have also reported similar incidents recently. Hilton and Starwood Hotels & Resorts last month disclosed attacks on payment processing systems.
Donald Trump's luxury hotel chain, Trump Hotel Collection, also confirmed the possibility of a data security incident.
FireEye said that Hyatt had hired it to help the company investigate the attack. FireEye's Mandiant unit is one of the biggest providers of response services to companies that are victims of cyber attacks.
Representatives at a Hyatt call centre set up to handle inquiries about the breach said the malware was programmed to collect payment cardholder names, card numbers, expiration dates and internal verification codes.
"We have taken steps to strengthen the security of our systems," Ms Sheppard said.
"Customers can feel confident using payment cards at Hyatt hotels worldwide."
Hyatt did not disclose the type of malware used in the attack.
Cyber intelligence firm iSight Partners in late November warned merchants about a new strain of payment-card-stealing malware dubbed ModPOS that it said evades almost all security software.
iSight held briefings with dozens of firms, including hospitality companies and retailers, to provide them with information on how to uncover ModPOS infections.For all the latest travel news from the UAE and Gulf countries, follow us on Twitter and Linkedin, like us on Facebook and subscribe to our YouTube page, which is updated daily.