On Sunday 10 April 2022 at 00:57 UTC, a HTTP GET flood targeted a education platform customer in North America. The attack peaked at 211.9 million requests per second and lasted 62 minutes. Traffic originated from 329 autonomous systems in 25 countries, predominantly misconfigured open reflectors.
| Vector | HTTP GET flood |
| Peak | 211.9 million requests per second |
| Duration | 62 min |
| Time to mitigation | 0.851 s |
| Attack traffic reaching origin | 0.065% |
| Legitimate traffic challenged | 0.13% |
Timeline
The attack was preceded by a publicly announced sales event. Request rates on the targeted routes exceeded their hourly baseline by a factor of 378 within 37 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 log streaming to your SIEM for faster correlation.
- Enable authenticated origin pulls.
- Lower challenge thresholds on authentication endpoints during high-risk events.
Clear and practical, thanks.
Thanks! Yes — the risk score and its components are included in every log record.
Thanks — sharing this with our on-call team.
Would love a follow-up on how you handle HTTP/3 fingerprinting.
The billing model is what got our finance team on board, honestly.
Verified good bots and allow-listed partners bypass challenges entirely.
How does the proof-of-work challenge behave on older Android devices? Any numbers below Android 10?
Nice to read a vendor blog that admits what went wrong.
Would love a follow-up on how you handle HTTP/3 fingerprinting.
Could you share the dataset behind the percentages?
Interesting that most attacks are under ten minutes. Our experience is similar.