On Tuesday 16 January 2024 at 12:26 UTC, a HTTP POST flood targeted a B2B SaaS customer in Iberia. The attack peaked at 873.1 million requests per second and lasted 90 minutes. Traffic originated from 4009 autonomous systems in 23 countries, predominantly residential proxy networks.
| Vector | HTTP POST flood |
| Peak | 873.1 million requests per second |
| Duration | 90 min |
| Time to mitigation | 0.219 s |
| Attack traffic reaching origin | 0.026% |
| Legitimate traffic challenged | 0.30% |
Timeline
The attack was preceded by a ransom note demanding payment in Monero. Request rates on the targeted routes exceeded their hourly baseline by a factor of 888 within 11 seconds. The risk score of participating clients crossed the challenge threshold automatically and proof-of-work difficulty rose with origin load.
What the customer saw
No customer-visible impact. The on-call engineer was notified and acknowledged the incident from the dashboard.
Recommendations
- Review allow-listed partner ranges quarterly.
- Enable authenticated origin pulls.
- Enable log streaming to your SIEM for faster correlation.
Solid runbook advice. The DNS-at-2am point hit home.