On Friday 9 April 2021 at 08:54 UTC, a search endpoint flood targeted a healthcare portal customer in Western Europe. The attack peaked at 612.7 million requests per second and lasted 34 minutes. Traffic originated from 3798 autonomous systems in 72 countries, predominantly a headless-browser farm.
| Vector | search endpoint flood |
| Peak | 612.7 million requests per second |
| Duration | 34 min |
| Time to mitigation | 0.695 s |
| Attack traffic reaching origin | 0.086% |
| Legitimate traffic challenged | 0.57% |
Timeline
The attack was preceded by a hacktivist channel announcing the target. Request rates on the targeted routes exceeded their hourly baseline by a factor of 727 within 12 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
Checkout conversion was unchanged compared with the same hour of the previous week.
Recommendations
- Enable authenticated origin pulls.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Review allow-listed partner ranges quarterly.
Could you share the dataset behind the percentages?
Thanks — sharing this with our on-call team.
Could you share the dataset behind the percentages?
Great write-up. We saw almost the same pattern on our login endpoint last month.
Machine-readable ranges are at /ips.json and via the API.