| Date | IP Address |
| 2023-09-03 | 3.90.96.235 (ClassC) |
| 2024-11-24 | 18.210.132.154 (ClassC) |
| 2024-12-23 | 54.221.192.231 (ClassC) |
| 2025-01-14 | 44.194.32.187 (ClassC) |
| Date | Domain | IP |
| ep.hmhpub.com | 2024-12-14 | 209.235.124.31 |
| cert.ep.hmhpub.com | 2024-11-15 | 45.60.11.203 |
| mxplanners.hmhpub.com | 2024-11-24 | 18.210.132.154 |
| www.hmhpub.com | 2024-11-24 | 3.231.72.27 |