INSPECTING ARCHIVED INTELLIGENCE (OUTDATED VERSION).

Nikkei Discloses Third Data Breach in a Month Exposing Records

| 2026-10-19 21:49 HIGH LOW DATA BREACH
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Executive Summary
AI-generated
On October 7, hackers used stolen credentials to access a development system within Nikkei's network during the early morning hours, exposing personal information stored in the cloud. The unauthorized access resulted in the exposure of approximately 1.83 million records containing personally identifiable information and other sensitive details, with subsets including full names, email addresses, physical addresses, telephone numbers, and dates of birth. Specifically, 150,000 records contained at least one of these data types, while 120,000 records included email addresses alone. The remaining 1.68 million records contain no identifiers, and no credit card information was exposed. Nikkei has since revoked the abused credentials and notified relevant authorities, with an ongoing examination to determine the cause and extent of the breach; as of October 16, there is currently no evidence that accessed information was misused or leaked online.
Technical Mitigations AI-generated
• Use strong, unique passwords for all accounts to prevent credential reuse. • Regularly review and update access permissions on cloud storage systems. • Monitor email addresses in the affected records for suspicious activity.
Intelligence Metadata
Actors / Malware / CVEs / Campaigns
Target & Sectors
JP
mediamedia
Incident Timeline
‎October 7
Hackers used stolen credentials to access a development system within Nikkei's network on October 7.
‎October 11
The Personal Information Protection Commission was notified by Nikkei on October 11 after the company revoked abused credentials.
organisation the Personal Information Protection Commission
Nikkei revoked the abused credentials and notified the Personal Information Protection Commission on October 11.
‎2026/10/12
Threat actors used stolen credentials to access a development system within Nikkei's network during the early morning hours of October 7.
‎October 16
Threat actors used social engineering tactics to target Nikkei, exposing 1.8 million records as of October 16.
‎2026/10/19
Threat actors used Microsoft 365 to send spear-phishing emails targeting Nikkei's staff, following a previous breach that compromised an employee's Google Workspace account.
data_breach 1.8 records
Nikkei discloses third data breach in a month, 1.8M records exposed.
organisation Nikkei Inc.
Nikkei Inc. disclosed a new data breach, the third in about a month, that exposed 1.83 million personal information records.
data_breach 1.83 information records
Nikkei Inc. disclosed a new data breach, the third in about a month, that exposed 1.83 million personal information records.
infrastructure Microsoft 365
In September, Nikkei announced that threat actors hijacked another employee’s Microsoft 365 account and used it to send spear-phishing emails to the firm’s staff.
organisation Microsoft
In September, Nikkei announced that threat actors hijacked another employee’s Microsoft 365 account and used it to send spear-phishing emails to the firm’s staff.
organisation Financial Times
Nikkei Inc. is a major Japanese business news and financial information group, owner of Financial Times, the country’s largest business-focused media company.
organisation Google Workspace
Earlier this month, the company disclosed a breach that occurred in late July, when hackers compromised an employee's Google Workspace account and accessed personal information belonging to employees and business partners.
organisation BleepingComputer
BleepingComputer has contacted Nikkei for more information about the latest breach, and we will update this post once we receive a response.
organisation The Blue Report 2026
The Blue Report 2026 measures defenses technique by technique across 338 million simulations run in customer production environments.
data_breach 150,000 records
The company said that 150,000 records contained at least one of the following data types: full names, email addresses, physical addresses, telephone numbers, and dates of birth.
data_breach 120,000 records
Email addresses appeared in 120,000 records.
data_breach 1.68 remaining records
The remaining 1.68 million records contain no identifiers, the company said, and no credit card information was exposed.
Tactical Metrics
Metrics
data_breach
1,800,000
Records
Nikkei discloses third data breach in a month, 1.8M records exposed.
Metrics
data_breach
1,830,000
Information Records
Nikkei Inc. disclosed a new data breach, the third in about a month, that exposed 1.83 million personal information records.
Metrics
infrastructure
‎Microsoft 365
Affected Product
In September, Nikkei announced that threat actors hijacked another employee’s Microsoft 365 account and used it to send spear-phishing emails to the firm’s staff.
Metrics
data_breach
150,000
Records
The company said that 150,000 records contained at least one of the following data types: full names, email addresses, physical addresses, telephone numbers, and dates of birth.
Metrics
data_breach
120,000
Records
Email addresses appeared in 120,000 records.
Metrics
data_breach
1,680,000
Remaining Records
The remaining 1.68 million records contain no identifiers, the company said, and no credit card information was exposed.
Intelligence Sources
BleepingComputer 2026-10-19