| Date | IP Address |
| 2023-06-24 | 54.209.63.70 (ClassC) |
| 2023-09-03 | 3.90.96.235 (ClassC) |
| 2024-02-05 | 23.20.149.239 (ClassC) |
| 2024-10-02 | 184.72.77.78 (ClassC) |
| 2024-11-02 | 54.159.39.108 (ClassC) |
| 2024-11-24 | 54.88.81.136 (ClassC) |
| 2024-12-29 | 3.229.202.231 (ClassC) |
| 2025-01-03 | 107.20.188.208 (ClassC) |
| 2025-01-13 | 18.213.27.29 (ClassC) |
| 2025-04-22 | 52.202.219.238 (ClassC) |
| 2025-06-17 | 44.206.12.68 (ClassC) |
| 2025-06-20 | 3.217.13.8 (ClassC) |
| 2025-06-30 | 54.166.126.155 (ClassC) |
| 2025-07-18 | 52.21.243.5 (ClassC) |
| 2025-07-29 | 52.72.142.124 (ClassC) |
| 2025-08-25 | 13.216.172.11 (ClassC) |
| 2025-09-01 | 52.44.46.255 (ClassC) |
| 2025-09-08 | 3.220.145.59 (ClassC) |
| 2026-02-12 | 3.227.107.66 (ClassC) |
| Date | Domain | IP |
| saxonhomeschool.harcourtachieve.com | 2025-05-10 | 44.207.125.31 |
| steckvaughn.harcourtachieve.com | 2025-03-06 | 44.219.204.92 |
| reads.harcourtachieve.com | 2024-11-24 | 54.88.81.136 |
| saxonpublishers.harcourtachieve.com | 2025-04-29 | 34.195.50.209 |
| steckvaughnadult.harcourtachieve.com | 2025-03-25 | 44.205.66.168 |
| www.harcourtachieve.com | 2026-01-20 | 209.235.125.89 |
| rigby.harcourtachieve.com | 2024-11-24 | 54.88.81.136 |