On Wednesday 16 August 2023 at 03:40 UTC, a UDP reflection (DNS) targeted a tax authority portal customer in Western Europe. The attack peaked at 234.2 Gbps and lasted 190 minutes. Traffic originated from 1253 autonomous systems in 87 countries, predominantly a headless-browser farm.
| Vector | UDP reflection (DNS) |
| Peak | 234.2 Gbps |
| Duration | 190 min |
| Time to mitigation | 0.429 s |
| Attack traffic reaching origin | 0.076% |
| Legitimate traffic challenged | 0.24% |
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 28 points of presence.
What the customer saw
The customer’s status page stayed green throughout; they learned about the attack from our notification.
Recommendations
- Enable authenticated origin pulls.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Keep origin IPs out of public DNS history.
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.
This matches what we see in iGaming around big matches.