Yokosuka Gakuin: ransomware hit its server and multiple photos and videos leaked

1. 2025-12-17

   It announced the information leak caused by the ransomware attack. [2] [3]

2. 2025-12-24

   It published a third report, asking people to tell it which published sites and similar material they found. [1] [3]

In early December a staff member reported being unable to connect to the server. The investigation found traces of unauthorized access from outside and the execution of a malicious program, and showed that multiple photos and videos had leaked. [2] [3]