Japanese companies disclose customer data breaches as report highlights AI-assisted attacks

Japanese companies including Yamato Transport and Nikkei disclosed breaches involving millions of sets of personal information in Japan, according to an October 17 report by The Japan Times, following an October 15 South China Morning Post report that linked a growing wave of corporate cyberattacks to hackers’ use of artificial intelligence.¹²

Customer information exposed

Yamato Transport said 5.31 million sets of personal information associated with some users of its deferred-payment service had been compromised, The Japan Times reported. The information included names, addresses and telephone numbers, and had been collected over roughly eight years beginning on October 1, 2018.¹

Business newspaper publisher Nikkei said a cloud platform used in developing systems was accessed without authorisation, exposing personal data in roughly 1.83 million records. According to The Japan Times, the affected material included names, postal addresses and email addresses.¹

The same report said cosmetics maker Fancl and its affiliate Attenir had announced a breach involving about 830,000 customers. Japan Post separately said information concerning about 600 users of its online service for requesting investigations into undelivered mail might have been compromised.¹

Identity documents and retention rules

According to The Japan Times, a cyberattack targeting the company that runs the Times Car car-sharing service exposed roughly 6.6 million personal-data records. About 1.6 million of those sets contained images of driving licences or other documents.¹

Park24, the operator’s parent company, said it would complete deletion of identity-verification document images by the end of October. It also said it would change its internal rules to require those images to be deleted immediately after identity checks, according to the newspaper.¹

AI and disruption

The South China Morning Post reported that artificial intelligence was helping hackers take advantage of longstanding security weaknesses and work across language barriers. Its October 15 account described an increase in attacks in recent weeks and cited more than 500 reported corporate-system breaches in the year to that month.²

The newspaper reported that ransomware struck cloud-hosting and data-centre company IDC Frontier on October 7, taking offline services on which 495 Japanese businesses and municipal bodies relied. It also reported that more than six million JR East customer accounts had been compromised and data relating to 6.43 million BookOff members had leaked.²

In a separate case, railway operator Keio said attackers claimed to have published its information after a system disruption, The Japan Times reported. The newspaper attributed the assessment that international hacker group Qilin had targeted Keio with ransomware to outside experts; publication of the information remained an attacker claim.¹