Marriott International revealed a second data breach on Tuesday - this time involving sensitive details of about 5.2 million of its guests.
Marriott said that for more than a month earlier this year, unscrupulous people might have gained access to the personal information of two of its hotels.
On March 31, Marriott International - the hotel company that owns global chains including Marriott, The Ritz Carlton and St. Regis - reported that details of over 5 million clients could have been breached between middle of January and the end of February, 2020.
Marriott said it had "no reason" to suspect that payment data had been compromised, but cautioned that names, addresses, telephone numbers, loyalty card data, birth dates and other travel details - had been taken into account in the infringement.
Starwood, a Marriott company, said its central reservation system was compromised in 2018, revealing personal details and data of 383 million guests. The data included five million unencrypted numbers of passports, and eight million details of credit cards.
Accessible details included full names, email addresses and telephone numbers, account numbers and account balance, birthday, gender and other related loyalty affiliations, such as airlines. ID and passport numbers, credit card information, and account passwords have not been affected, the firm said.
Stephanie Linnartz, Marriott's president of Consumer Division, said in an email to potentially impacted customers that the company was setting up a database through which they would see if their information was involved and provided Experian's one year free personal monitoring service.
Marriott has already contacted concerned customers and they will be expected to reset their passwords, while worried guests may also check whether they have been affected via a dedicated portal as well.
Customers whose data could have been infringed will also be given an enrolment - free of charge - for a year in IdentityWorks, a personal information monitoring program.
The Marriott group suffered a big data breach in 2018 where up to half a billion customers were affected and some credit card information were compromised - the largest hack in history.
While small data breaches, especially of non-critical information, tend to be small blips on the radar, Tuesday's bad news could not come at a worse time for Marriott and the entire hotel industry.
The coronavirus pandemic has caused hotel chains all over the world to close down properties and lay off employees. The salary of Marriott chief executive officer Arne Sorenson was suspended for the rest of the year in March, while other top executives are seeing a 50 percent pay cut.
