> JapanHacked_
[Investigating][Severity: Critical][Insider]

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

  1. Detected 2025-09-16
  2. Disclosed 2025-10-14
  3. 28 days

Attack or cause

Method
[Insider]
Impact
[Data leak]
Entry point
Unknown
Affected, as stated
11,356

Data exposed or at risk

[Name]

Organizations involved

Open in organization search

Sources

  1. [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. [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