On Monday 28 October 2024 at 03:40 UTC, a credential stuffing targeted a healthcare portal customer in the Nordics. The attack peaked at 880.4 million requests per second and lasted 11 minutes. Traffic originated from 2511 autonomous systems in 16 countries, predominantly a Mirai-derived IoT botnet.
| Vector | credential stuffing |
| Peak | 880.4 million requests per second |
| Duration | 11 min |
| Time to mitigation | 0.127 s |
| Attack traffic reaching origin | 0.029% |
| Legitimate traffic challenged | 0.78% |
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 665 within 22 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
The customer’s status page stayed green throughout; they learned about the attack from our notification.
Recommendations
- Keep origin IPs out of public DNS history.
- Enable authenticated origin pulls.
- Enable log streaming to your SIEM for faster correlation.
Nice to read a vendor blog that admits what went wrong.
Nice to read a vendor blog that admits what went wrong.
How do you avoid challenging uptime monitors and partners?
Would love a follow-up on how you handle HTTP/3 fingerprinting.
Verified good bots and allow-listed partners bypass challenges entirely.
Carpet bombing is nasty. Good to see a clear explanation of it.
The point about origin IPs leaking through certificate transparency logs is underrated.