On Saturday 27 November 2021 at 19:55 UTC, a UDP reflection (DNS) targeted a online casino customer in Iberia. The attack peaked at 154.9 Gbps and lasted 11 minutes. Traffic originated from 984 autonomous systems in 111 countries, predominantly a rented booter service.
| Vector | UDP reflection (DNS) |
| Peak | 154.9 Gbps |
| Duration | 11 min |
| Time to mitigation | 0.131 s |
| Attack traffic reaching origin | 0.069% |
| Legitimate traffic challenged | 0.51% |
Timeline
The attack was preceded by a competitor’s product launch. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 17 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.
- Review allow-listed partner ranges quarterly.
- Enable log streaming to your SIEM for faster correlation.
We moved from a scrubbing provider to always-on last year; time to mitigation went from minutes to basically nothing.
Machine-readable ranges are at /ips.json and via the API.
Nice to read a vendor blog that admits what went wrong.
The point about origin IPs leaking through certificate transparency logs is underrated.
Clear and practical, thanks.
Thanks — sharing this with our on-call team.
Thanks! Yes — the risk score and its components are included in every log record.
Our auditors asked for exactly this kind of incident evidence under DORA.
Carpet bombing is nasty. Good to see a clear explanation of it.
Good question. We will cover that in a follow-up post.
Thanks — sharing this with our on-call team.
Do you publish the edge IP ranges in a machine-readable format?