On Thursday 4 April 2024 at 09:58 UTC, a UDP reflection (DNS) targeted a developer platform customer in the Middle East. The attack peaked at 79.9 Gbps and lasted 148 minutes. Traffic originated from 4013 autonomous systems in 115 countries, predominantly compromised cloud VMs.
| Vector | UDP reflection (DNS) |
| Peak | 79.9 Gbps |
| Duration | 148 min |
| Time to mitigation | 0.905 s |
| Attack traffic reaching origin | 0.051% |
| Legitimate traffic challenged | 0.10% |
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 35 points of presence.
What the customer saw
A brief increase in p99 latency of 93 ms during the first minute, then normal service.
Recommendations
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Keep origin IPs out of public DNS history.
- Review allow-listed partner ranges quarterly.
Do you publish the edge IP ranges in a machine-readable format?
The point about origin IPs leaking through certificate transparency logs is underrated.
Machine-readable ranges are at /ips.json and via the API.
Great write-up. We saw almost the same pattern on our login endpoint last month.
We moved from a scrubbing provider to always-on last year; time to mitigation went from minutes to basically nothing.
Our auditors asked for exactly this kind of incident evidence under DORA.
Is the risk score exposed in the logs so we can build our own dashboards on it?
How does the proof-of-work challenge behave on older Android devices? Any numbers below Android 10?