On Sunday 28 May 2023 at 06:51 UTC, a carpet-bombing UDP flood targeted a online payments customer in Iberia. The attack peaked at 131.6 Gbps and lasted 123 minutes. Traffic originated from 2785 autonomous systems in 66 countries, predominantly a Mirai-derived IoT botnet.
| Vector | carpet-bombing UDP flood |
| Peak | 131.6 Gbps |
| Duration | 123 min |
| Time to mitigation | 0.643 s |
| Attack traffic reaching origin | 0.086% |
| Legitimate traffic challenged | 0.13% |
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 25 points of presence.
What the customer saw
The customer’s status page stayed green throughout; they learned about the attack from our notification.
Recommendations
- Add a dedicated rate limit for the targeted route.
- Keep origin IPs out of public DNS history.
- Lower challenge thresholds on authentication endpoints during high-risk events.
How do you avoid challenging uptime monitors and partners?
Any plans to support per-tenant limits keyed on a JWT claim?
Good question. We will cover that in a follow-up post.
Interesting that most attacks are under ten minutes. Our experience is similar.