More Japanese companies have revealed that they have experienced major customer data breaches due to cyberattacks.
JR East said that about 6.09 million customer accounts may have been compromised, while JR Kyushu said about 1.3 million customer accounts may have been compromised. Both were a result of a ransomware attack on IDC Frontier, a cloud services subsidiary of SoftBank, they said Friday.
Bookoff Group Holdings, a secondhand goods retailer, reported that its subsidiary responsible for managing membership data had suffered unauthorized access, possibly resulting in a data breach affecting up to 6.43 million customers.
Daiichikosho, the operator of the Big Echo karaoke chain, also said personal information on about 8.72 million customers may have been compromised due to unauthorized access to a system managed by an external contractor.
Adventure Inc., the operator of the Skyticket travel booking website, reported a potential breach involving about 14.64 million sets of personal information, following a cyberattack on its servers and the business management system for its booking website.
The potentially affected information includes email addresses at JR East and customer names, dates of birth and telephone numbers at the other three companies. Adventure said it had confirmed that credit card and passport numbers had not leaked.
The companies respectively said that they had found no evidence of unauthorized use of the affected information by third parties. They are urging customers to watch out for suspicious emails and phone calls.
