On Saturday 26 June 2021 at 23:09 UTC, a UDP reflection (NTP) targeted a fashion retail customer in the Nordics. The attack peaked at 206.9 Gbps and lasted 149 minutes. Traffic originated from 3785 autonomous systems in 11 countries, predominantly a rented booter service.
| Vector | UDP reflection (NTP) |
| Peak | 206.9 Gbps |
| Duration | 149 min |
| Time to mitigation | 0.195 s |
| Attack traffic reaching origin | 0.073% |
| Legitimate traffic challenged | 0.46% |
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 39 points of presence.
What the customer saw
A brief increase in p99 latency of 172 ms during the first minute, then normal service.
Recommendations
- Enable authenticated origin pulls.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Enable log streaming to your SIEM for faster correlation.