On Friday 23 February 2024 at 18:02 UTC, a UDP reflection (DNS) targeted a healthcare portal customer in Western Europe. The attack peaked at 28.2 Gbps and lasted 127 minutes. Traffic originated from 3786 autonomous systems in 14 countries, predominantly a Mirai-derived IoT botnet.
| Vector | UDP reflection (DNS) |
| Peak | 28.2 Gbps |
| Duration | 127 min |
| Time to mitigation | 0.111 s |
| Attack traffic reaching origin | 0.048% |
| Legitimate traffic challenged | 0.19% |
Timeline
The attack was preceded by a ransom note demanding payment in Monero. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 27 points of presence.
What the customer saw
Checkout conversion was unchanged compared with the same hour of the previous week.
Recommendations
- Keep origin IPs out of public DNS history.
- Add a dedicated rate limit for the targeted route.
- Lower challenge thresholds on authentication endpoints during high-risk events.