On Monday 10 April 2023 at 22:24 UTC, a UDP reflection (DNS) targeted a electronics retail customer in North America. The attack peaked at 198.9 Gbps and lasted 61 minutes. Traffic originated from 3469 autonomous systems in 72 countries, predominantly a Mirai-derived IoT botnet.
| Vector | UDP reflection (DNS) |
| Peak | 198.9 Gbps |
| Duration | 61 min |
| Time to mitigation | 0.491 s |
| Attack traffic reaching origin | 0.078% |
| Legitimate traffic challenged | 0.08% |
Timeline
The attack was preceded by an extortion email received two days earlier. 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 225 ms during the first minute, then normal service.
Recommendations
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Enable authenticated origin pulls.
- Enable log streaming to your SIEM for faster correlation.
The billing model is what got our finance team on board, honestly.
Great to hear, thanks for sharing your experience.
Nice to read a vendor blog that admits what went wrong.