| Date | IP Address |
| 2020-08-24 | 52.222.221.143 (ClassC) |
| 2024-10-05 | 3.163.165.117 (ClassC) |
| 2024-11-25 | 99.84.66.13 (ClassC) |
| 2025-01-06 | 99.84.66.122 (ClassC) |
| 2025-02-20 | 13.249.91.126 (ClassC) |
| 2026-01-20 | 3.169.173.65 (ClassC) |
| Date | Domain | IP |
| download.kobun.co.jp | 2023-12-12 | 204.246.191.100 |
| student.trial.cbt-tower.kobun.co.jp | 2024-10-04 | 3.163.24.79 |
| www.kobun.co.jp | 2024-10-05 | 3.163.165.117 |