Over the weekend, Japanese publishing giant Nikkei disclosed that unknown attackers recently breached two employee email accounts and used one to send thousands of phishing emails.
In a Sunday statement, the company said an employee's Google Workspace account was accessed in late July, exposing the personal information of employees and business partners. Nikkei changed the account's password after discovering the breach in early August, following a notification from Google.
While this incident may have exposed the names and email addresses of 1,646 individuals, Nikkei says the affected data doesn't include information about readers or interviewees.
More recently, threat actors accessed another employee's Microsoft 365 account in September and used it to send 9,000 phishing emails targeting Nikkei staff and interviewees.
"On September 30th, emails containing links to malicious websites were sent to internal staff and to interviewees with whom several employees had been in contact," the media giant said. "Our company has changed its passwords, and no unauthorized logins have been confirmed since then. We have contacted the recipients individually and requested that they delete the emails."
The company also warned affected individuals to watch for suspicious emails that may impersonate Nikkei or its subsidiaries in new phishing attacks.
Nikkei has yet to attribute the attacks to a specific threat actor or hacking group and hasn't shared whether the two incidents are connected.
These are the latest in a string of security incidents Nikkei has disclosed in recent years. Last year, the company also revealed that its Slack messaging platform had been breached, affecting more than 17,000 employees and business partners. In May 2022, Nikkei's Singapore subsidiary was hit by a ransomware attack that affected a server "likely" containing customer data. Three years earlier, in late September 2019, Nikkei lost approximately $29 million in a business email compromise (BEC) attack that targeted a Nikkei America employee.
Nikkei owns the Financial Times and The Nikkei, the world's largest financial newspaper, and is one of the world's largest media corporations.