On Tuesday 25 August 2026 at 01:22 UTC, a HTTP GET flood targeted a tax authority portal customer in the UK. The attack peaked at 578.0 million requests per second and lasted 85 minutes. Traffic originated from 1788 autonomous systems in 12 countries, predominantly hijacked home routers.
| Vector | HTTP GET flood |
| Peak | 578.0 million requests per second |
| Duration | 85 min |
| Time to mitigation | 0.251 s |
| Attack traffic reaching origin | 0.004% |
| Legitimate traffic challenged | 0.10% |
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 558 within 19 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
A brief increase in p99 latency of 233 ms during the first minute, then normal service.
Recommendations
- Enable log streaming to your SIEM for faster correlation.
- Review allow-listed partner ranges quarterly.
- Keep origin IPs out of public DNS history.