Nikkei Email Account Breaches Expose Contacts and Send 9,000 Phishing Emails

Japanese publisher Nikkei disclosed breaches of two employee email accounts across Google Workspace and Microsoft 365. The Google Workspace account was compromised in late July, potentially exposing the names and email addresses of 1,646 employees and business partners; readers and interviewees were not included in that potential exposure. Attackers accessed a separate Microsoft 365 account in September and used it to send 9,000 phishing emails to Nikkei employees and interviewees on September 30.

Nikkei changed the affected accounts’ passwords, contacted phishing recipients, and warned affected individuals about further impersonation attempts. The attackers remain unidentified, and the company has not established whether the two incidents are connected. The compromises create a continuing risk of phishing messages appearing to originate from trusted Nikkei contacts.