On Tuesday 20 August 2024 at 13:59 UTC, a GRE flood targeted a education platform customer in the Benelux. The attack peaked at 225.6 Gbps and lasted 22 minutes. Traffic originated from 4111 autonomous systems in 49 countries, predominantly residential proxy networks.
| Vector | GRE flood |
| Peak | 225.6 Gbps |
| Duration | 22 min |
| Time to mitigation | 0.660 s |
| Attack traffic reaching origin | 0.081% |
| Legitimate traffic challenged | 0.02% |
Timeline
The attack was preceded by a hacktivist channel announcing the target. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 22 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 authenticated origin pulls.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Review allow-listed partner ranges quarterly.
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.
Thanks! Yes — the risk score and its components are included in every log record.
The point about origin IPs leaking through certificate transparency logs is underrated.
Carpet bombing is nasty. Good to see a clear explanation of it.
Any plans to support per-tenant limits keyed on a JWT claim?
Is the risk score exposed in the logs so we can build our own dashboards on it?
The billing model is what got our finance team on board, honestly.
Great write-up. We saw almost the same pattern on our login endpoint last month.
The point about origin IPs leaking through certificate transparency logs is underrated.
Machine-readable ranges are at /ips.json and via the API.
Solid runbook advice. The DNS-at-2am point hit home.
Machine-readable ranges are at /ips.json and via the API.