| Date | IP Address |
| 2023-08-29 | 3.90.96.235 (ClassC) |
| 2024-11-02 | 54.159.39.108 (ClassC) |
| 2025-02-19 | 50.17.16.132 (ClassC) |
| 2025-03-02 | 54.204.140.1 (ClassC) |
| 2025-05-03 | 3.214.241.145 (ClassC) |
| Date | Domain | IP |
| owa.hmhpub.com | 2025-03-07 | 207.127.63.247 |
| ep.hmhpub.com | 2025-04-03 | 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 |
| ws.hmhpub.com | 2025-02-19 | 50.17.16.132 |
| techsupport.hmhpub.com | 2025-02-19 | 50.17.16.132 |
| www.hmhpub.com | 2024-11-24 | 3.231.72.27 |