On Sunday 23 January 2022 at 07:29 UTC, a UDP reflection (NTP) targeted a developer platform customer in North America. The attack peaked at 263.0 Gbps and lasted 172 minutes. Traffic originated from 2498 autonomous systems in 81 countries, predominantly mobile carrier ranges.
| Vector | UDP reflection (NTP) |
| Peak | 263.0 Gbps |
| Duration | 172 min |
| Time to mitigation | 0.419 s |
| Attack traffic reaching origin | 0.035% |
| Legitimate traffic challenged | 0.61% |
Timeline
The attack was preceded by no stated motive. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 34 points of presence.
What the customer saw
The customer’s status page stayed green throughout; they learned about the attack from our notification.
Recommendations
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Enable authenticated origin pulls.
- Keep origin IPs out of public DNS history.
Great write-up. We saw almost the same pattern on our login endpoint last month.
How does the proof-of-work challenge behave on older Android devices? Any numbers below Android 10?
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.
Verified good bots and allow-listed partners bypass challenges entirely.
The point about origin IPs leaking through certificate transparency logs is underrated.
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.
Great write-up. We saw almost the same pattern on our login endpoint last month.
Great write-up. We saw almost the same pattern on our login endpoint last month.
Would love a follow-up on how you handle HTTP/3 fingerprinting.
Nice to read a vendor blog that admits what went wrong.