On Wednesday 27 December 2023 at 07:26 UTC, a carpet-bombing UDP flood targeted a healthcare portal customer in Iberia. The attack peaked at 277.6 Gbps and lasted 159 minutes. Traffic originated from 1011 autonomous systems in 94 countries, predominantly a rented booter service.
| Vector | carpet-bombing UDP flood |
| Peak | 277.6 Gbps |
| Duration | 159 min |
| Time to mitigation | 0.928 s |
| Attack traffic reaching origin | 0.087% |
| Legitimate traffic challenged | 0.58% |
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 24 points of presence.
What the customer saw
The customer’s status page stayed green throughout; they learned about the attack from our notification.
Recommendations
- Keep origin IPs out of public DNS history.
- Add a dedicated rate limit for the targeted route.
- Review allow-listed partner ranges quarterly.
The point about origin IPs leaking through certificate transparency logs is underrated.
Solid runbook advice. The DNS-at-2am point hit home.
Good question. We will cover that in a follow-up post.
Nice to read a vendor blog that admits what went wrong.
Clear and practical, thanks.
Could you share the dataset behind the percentages?
Good question. We will cover that in a follow-up post.