| Date | IP Address |
| 2022-12-02 | 52.200.203.18 (ClassC) |
| 2025-04-11 | 34.231.11.210 (ClassC) |
| 2025-06-03 | 54.165.166.93 (ClassC) |
| 2025-06-25 | 3.223.57.114 (ClassC) |
| 2025-07-21 | 52.7.57.189 (ClassC) |
| 2025-09-01 | 34.226.29.128 (ClassC) |
| 2025-10-24 | 3.223.23.116 (ClassC) |
| 2025-11-18 | 3.215.168.72 (ClassC) |
| Date | Domain | IP |
| curiousgeorge-v1.int.webnp.hmhco.com | 2024-08-07 | 54.82.51.61 |
| hmhco-v1.int.webnp.hmhco.com | 2024-08-07 | 52.2.104.230 |
| api-consumer-v1.int.webnp.hmhco.com | 2024-08-07 | 54.82.51.61 |
| cliffsnotes-v1.int.webnp.hmhco.com | 2024-08-07 | 52.2.104.230 |
| subscriptions-v1.int.webnp.hmhco.com | 2024-08-07 | 52.2.104.230 |
| api-subscriptions-v1.int.webnp.hmhco.com | 2024-08-07 | 54.82.51.61 |
| admin-subscriptions-v1.int.webnp.hmhco.com | 2024-08-07 | 52.2.104.230 |
| gomathacademy-v1.int.webnp.hmhco.com | 2024-08-07 | 54.82.51.61 |
| web-delivery-v1.int.webnp.hmhco.com | 2025-08-04 | 18.235.151.113 |
| hmhco-v2.int.webnp.hmhco.com | 2024-08-07 | 54.82.51.61 |
| hmhco-v1.cert.webnp.hmhco.com | 2025-10-30 | 54.166.166.198 |
| gomathacademy-v1.cert.webnp.hmhco.com | 2025-08-10 | 45.60.11.203 |
| web-delivery-v1.cert.webnp.hmhco.com | 2024-06-03 | 44.207.80.202 |
| cliffsnotes-v1.dev.webnp.hmhco.com | 2024-08-09 | 44.209.124.240 |
| gomathacademy-v1.dev.webnp.hmhco.com | 2025-04-11 | 34.231.11.210 |
| web-delivery-int.dev.webnp.hmhco.com | 2025-08-10 | 54.167.13.139 |