On Tuesday 9 September 2025 at 14:24 UTC, a carpet-bombing UDP flood targeted a healthcare portal customer in the UK. The attack peaked at 389.6 Gbps and lasted 62 minutes. Traffic originated from 3926 autonomous systems in 13 countries, predominantly mobile carrier ranges.
| Vector | carpet-bombing UDP flood |
| Peak | 389.6 Gbps |
| Duration | 62 min |
| Time to mitigation | 0.241 s |
| Attack traffic reaching origin | 0.032% |
| Legitimate traffic challenged | 0.34% |
Timeline
The attack was preceded by a competitor’s product launch. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 17 points of presence.
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.
- Add a dedicated rate limit for the targeted route.
- Lower challenge thresholds on authentication endpoints during high-risk events.