Nikkei Shimbun discloses third data breach in a month affecting 1.83 million records

Japan’s Nihon Keizai Shimbun, commonly known as Nikkei Shimbun, has disclosed its third cybersecurity incident in about a month, revealing that hackers accessed 1.83 million records.

The company said some of the exposed data contained personally identifiable information (PII) and other sensitive information. However, most of the affected records did not contain personal identifiers.

150,000 records contained personal information

According to Nikkei Shimbun, approximately 150,000 records contained at least one of the following data types:

• Name
• Email address
• Physical address
• Phone number
• Date of birth

Email addresses were included in approximately 120,000 records.

The remaining 1.68 million records did not contain identifiers, and the company said no credit card information was compromised.

Hackers used stolen credentials to access development systems

Nihon Keizai Shimbun said in a notice published late last week that hackers used stolen credentials to access development systems within its network during the early morning hours of October 7.

The unauthorized access resulted in the exposure of personal information stored in the company’s cloud environment.

Nikkei Shimbun revoked the misused credentials and notified Japan’s Personal Information Protection Commission on October 11.

The company is investigating the full scope of the breach. As of October 16, it said there was no evidence that the accessed information had been misused or leaked online.

Nikkei also reported no signs of system compromise or data tampering resulting from the incident, and said no service outages occurred.

The company said it will notify affected individuals separately.

“We are working immediately to investigate the extent of the damage and determine the cause, and we will take the necessary measures to strengthen safety,” Nikkei Shimbun stated.

Third Nikkei cybersecurity incident recently disclosed

This is the third cybersecurity incident recently revealed by Nikkei Shimbun.

Earlier this month, the company disclosed a breach that occurred in late July. In that incident, hackers compromised employees’ Google Workspace accounts and accessed personal information belonging to employees and business partners.

In September, Nikkei Shimbun announced that an attacker had taken over another employee’s Microsoft 365 account and used it to send a spear-phishing email to company staff.

Nihon Keizai Shimbun is Japan’s leading business news and financial information group and owns the Financial Times. The company has more than 10,100 employees and annual revenue of $2.5 billion (393.8 billion yen).

BleepingComputer reached out to Nikkei Shimbun for more information about the latest breach. We will update this article if the company responds.

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