On October 4, Nikkei Inc. announced that Microsoft 365 accounts used by its employees for business had been targeted by a cyberattack, with a third party believed to have gained unauthorized access. Approximately 9,000 suspicious emails, impersonating employees, were reportedly sent. Nikkei stated that passwords have been changed, and no further unauthorized logins have been confirmed since. They are individually contacting recipients to request the deletion of these emails.
The company also simultaneously announced suspicions that Google Workspace accounts used by employees had experienced unauthorized external logins since late July, potentially leading to the leakage of email addresses and names for 1,646 individuals, including employees and business partners. This was discovered in early August following a notification from Google, and no unauthorized logins have been confirmed since passwords were changed.
On X (formerly Twitter), a flurry of reactions followed, with users pointing out the seriousness of the incident and expressing concern over the recent surge in cyberattacks. Comments included: "Nikkei too?! Isn't this serious?" and "This is the most malicious kind of hijacking attack. Nikkei's credibility has been exploited." In addition to worries about successive unauthorized accesses, many voices highlighted anxiety regarding corporate security measures.
