Nikkei discloses employee Google and Microsoft account breaches

Nikkei says late-July Google and September 30 Microsoft employee account compromises exposed 1,646 contacts and sent about 9,000 phishing emails.

Japanese publisher Nikkei disclosed that attackers accessed an employee Google Workspace account in or from late July, exposing names and email addresses of 1,646 employees and business partners. BleepingComputer said the exposure did not include readers or interviewees, while Infosecurity Magazine described those affected as employees, partners, and others and said the data was potentially exposed. A separate Microsoft 365 account was used on September 30 to send about 9,000 phishing emails with malicious links; BleepingComputer said the account was accessed in September and that messages went to staff and interviewees, and Infosecurity said some mailbox content may have been exposed. Nikkei reset the passwords, told BleepingComputer that no further unauthorized logins were seen, and according to Infosecurity reported the cases to Japan’s Personal Information Protection Commission, without attributing the incidents or explaining how access occurred. Infosecurity also reported that group unit Nikkei BP disclosed a September 30 phishing-led mailbox compromise affecting 26 contacts, and a 2025 Slack breach linked to infostealer-stolen credentials that exposed 17,368 people, which BleepingComputer described only as a prior Slack breach of more than 17,000 people. BleepingComputer additionally noted a 2022 ransomware attack on Nikkei’s Singapore subsidiary and a 2019 business-email-compromise loss of about $29 million.