On Friday 7 July 2023 at 02:28 UTC, a SYN flood targeted a online casino customer in Iberia. The attack peaked at 227.0 Gbps and lasted 4 minutes. Traffic originated from 3157 autonomous systems in 54 countries, predominantly misconfigured open reflectors.
| Vector | SYN flood |
| Peak | 227.0 Gbps |
| Duration | 4 min |
| Time to mitigation | 0.255 s |
| Attack traffic reaching origin | 0.064% |
| Legitimate traffic challenged | 0.34% |
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 16 points of presence.
What the customer saw
Checkout conversion was unchanged compared with the same hour of the previous week.
Recommendations
- Add a dedicated rate limit for the targeted route.
- Enable log streaming to your SIEM for faster correlation.
- Enable authenticated origin pulls.
The point about origin IPs leaking through certificate transparency logs is underrated.
Do you publish the edge IP ranges in a machine-readable format?
Our auditors asked for exactly this kind of incident evidence under DORA.
How does the proof-of-work challenge behave on older Android devices? Any numbers below Android 10?
Interesting that most attacks are under ten minutes. Our experience is similar.
Good question. We will cover that in a follow-up post.