On Sunday 17 September 2023 at 00:39 UTC, a UDP reflection (DNS) targeted a news publisher customer in the UK. The attack peaked at 280.3 Gbps and lasted 32 minutes. Traffic originated from 797 autonomous systems in 52 countries, predominantly compromised cloud VMs.
| Vector | UDP reflection (DNS) |
| Peak | 280.3 Gbps |
| Duration | 32 min |
| Time to mitigation | 0.872 s |
| Attack traffic reaching origin | 0.009% |
| Legitimate traffic challenged | 0.19% |
Timeline
The attack was preceded by no stated motive. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 33 points of presence.
What the customer saw
Checkout conversion was unchanged compared with the same hour of the previous week.
Recommendations
- Enable authenticated origin pulls.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Add a dedicated rate limit for the targeted route.