daiichi-life-hr-2026 · Disclosed 2026-10-02
第一生命: unauthorized access and impact
Unauthorized access to the employee HR system was detected on September 24. Potential exposure covers about 50,000 employees and 70,000 former employees; customer-data access is unconfirmed.
Outcome: Confirmed breach
Entry path and evidence
Timeline
Disclosure date established by the reviewed notice. [s1]
Reported response
- Reported fact
Former employees were notified of precautions and a dedicated contact channel.
[s1]p.1 冒頭 / 現時点で閲覧され、外部に流出した可能性のある個人情報
Evidence relevant to prevention
Insufficient evidence
Undisclosed entry or patch timing prevents an avoidability assessment. Inspect privileges, retrieval logs, retention and deployed configuration using the linked rules.
Editorial assessment; not a determination of liability. [s1]
Unknowns and AI involvement
The reviewed disclosures do not establish attacker use of AI.
The entry mechanism and confirmed exfiltration scope are undisclosed.
Sources
[s1] 第一ライフグループ・第一生命 · Primary source
第一ライフグループ・第一生命：事故に関する公表資料 ↗Reviewed 2026-10-09