On Saturday 27 August 2022 at 05:56 UTC, a HTTP GET flood targeted a B2B SaaS customer in North America. The attack peaked at 190.8 million requests per second and lasted 29 minutes. Traffic originated from 1892 autonomous systems in 77 countries, predominantly a Mirai-derived IoT botnet.
| Vector | HTTP GET flood |
| Peak | 190.8 million requests per second |
| Duration | 29 min |
| Time to mitigation | 0.419 s |
| Attack traffic reaching origin | 0.083% |
| Legitimate traffic challenged | 0.05% |
Timeline
The attack was preceded by an extortion email received two days earlier. Request rates on the targeted routes exceeded their hourly baseline by a factor of 585 within 18 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
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Enable log streaming to your SIEM for faster correlation.
- Add a dedicated rate limit for the targeted route.
Our auditors asked for exactly this kind of incident evidence under DORA.