On Wednesday 7 December 2022 at 23:19 UTC, a UDP reflection (DNS) targeted a B2B SaaS customer in Southeast Asia. The attack peaked at 120.7 Gbps and lasted 49 minutes. Traffic originated from 2949 autonomous systems in 107 countries, predominantly misconfigured open reflectors.
| Vector | UDP reflection (DNS) |
| Peak | 120.7 Gbps |
| Duration | 49 min |
| Time to mitigation | 0.950 s |
| Attack traffic reaching origin | 0.054% |
| Legitimate traffic challenged | 0.62% |
Timeline
The attack was preceded by a breaking political story. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 15 points of presence.
What the customer saw
A brief increase in p99 latency of 168 ms during the first minute, then normal service.
Recommendations
- Keep origin IPs out of public DNS history.
- Review allow-listed partner ranges quarterly.
- Add a dedicated rate limit for the targeted route.