Yamato Transport: former employee took business partner data
On September 16 the company established that a former employee had passed 26,790 business-customer entries concerning 11,356 companies to two firms. Personal names appeared in 750 billing entries and 324 employee/former-employee entries. One sales-use incident was confirmed. Both recipients said they deleted the data, with verification continuing. The November 14 findings left the total business-record count unchanged but revised the subset containing personal names to 751 and confirmed two uses for sales activity by one recipient company.
Disclosed
2025-10-14
Organizations involved
11356
Leaked or at risk
26.8K
26,790
Downtime
Unknown
Timeline
- Detected 2025-09-16
- Disclosed 2025-10-14
- 28 days
Attack or cause
- Method
- [Insider]
- Impact
- [Data leak]
- Entry point
- Unknown
- Affected, as stated
- 11,356
Data exposed or at risk
Organizations involved
[Breached][Major]Tokyo, ChuoTransport and postal services26,790 leaked
Yamato Transport Co., Ltd.
Sources
- [1][Official]元従業員による情報の不正持ち出しに関するご報告とお詫びYamato Transport Co., Ltd. · 2025-10-14
- [2][Official]元従業員による情報の不正持ち出しに関する調査結果のご報告Yamato Transport · 2025-11-14