On Wednesday 2 April 2025 at 01:43 UTC, a UDP reflection (DNS) targeted a sports betting customer in North America. The attack peaked at 117.6 Gbps and lasted 69 minutes. Traffic originated from 3913 autonomous systems in 25 countries, predominantly a headless-browser farm.
| Vector | UDP reflection (DNS) |
| Peak | 117.6 Gbps |
| Duration | 69 min |
| Time to mitigation | 0.901 s |
| Attack traffic reaching origin | 0.001% |
| Legitimate traffic challenged | 0.37% |
Timeline
The attack was preceded by a publicly announced sales event. 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
No customer-visible impact. The on-call engineer was notified and acknowledged the incident from the dashboard.
Recommendations
- Enable log streaming to your SIEM for faster correlation.
- Review allow-listed partner ranges quarterly.
- Lower challenge thresholds on authentication endpoints during high-risk events.
We moved from a scrubbing provider to always-on last year; time to mitigation went from minutes to basically nothing.
Clear and practical, thanks.
Good question. We will cover that in a follow-up post.
How does the proof-of-work challenge behave on older Android devices? Any numbers below Android 10?
Nice to read a vendor blog that admits what went wrong.
The point about origin IPs leaking through certificate transparency logs is underrated.
Carpet bombing is nasty. Good to see a clear explanation of it.
We moved from a scrubbing provider to always-on last year; time to mitigation went from minutes to basically nothing.