Marriott on Tuesday disclosed a new data breach that could impact up to 5.2 million of its guests. The incident is related to an internal application used by Marriott hotels.
According to the company, its corporate-owned and franchised hotels use an application to provide services to guests. At the end of February, Marriott discovered that the credentials of two employees at a franchise property were used to access “an unexpected amount of guest information.”
The investigation is ongoing, but it appears that the unauthorized access started in mid-January. Marriott says it has invalidated the compromised credentials, but the attackers may have obtained information on as many as 5.2 million individuals.
Marriott says the exposed information includes name, mailing address, email address, phone number, loyalty account number and point balance, company name, gender, birth day and month, information on the customer’s preferences (e.g. room and language preferences), and details on partnerships and affiliations (e.g. linked airline loyalty programs). However, not all of this information was present for every affected guest.
The company claims it has found no evidence that Marriott Bonvoy account passwords or PINs, passport information, payment card information, national IDs or driver’s license numbers have been compromised. Nevertheless, Bonvoy account passwords have been reset and users will be prompted to enable multi-factor authentication.
Affected individuals are being notified and Marriott is offering them identity protection services free of charge for one year. A dedicated website has been set up to assist impacted guests.
“Marriott carries insurance, including cyber insurance, commensurate with its size and the nature of its operations, and the company is working with its insurers to assess coverage. The company does not currently believe that its total costs related to this incident will be significant,” Marriott stated.
In November 2018, Marriott revealed that it had been hit by a massive data breach impacting roughly 500 million people who had stayed at Starwood hotel properties. The attackers had access to the Starwood network for years before their presence was detected.
The company later said the incident, which has been attributed by some to hackers working for the Chinese government, only impacted 383 million guests, but it’s still one of the biggest data breaches on record. Furthermore, the incident resulted in the exposure of highly sensitive information, including passport numbers and payment card details.
The UK Information Commissioner’s Office (ICO) announced in July 2019 that Marriott should pay a $124 million fine for infringements of the General Data Protection Regulation (GDPR) resulting from the breach, but Marriott said it would appeal the decision. The case has yet to be settled.
Related: Lawsuits Filed Against Marriott Over Massive Data Breach
Related: Data Breach Cost Marriott $28 Million So Far

Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.
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