On Sunday 17 March 2024 at 19:35 UTC, a SYN flood targeted a municipal services customer in the Nordics. The attack peaked at 36.3 Gbps and lasted 21 minutes. Traffic originated from 2583 autonomous systems in 69 countries, predominantly compromised cloud VMs.
| Vector | SYN flood |
| Peak | 36.3 Gbps |
| Duration | 21 min |
| Time to mitigation | 0.101 s |
| Attack traffic reaching origin | 0.067% |
| Legitimate traffic challenged | 0.19% |
Timeline
The attack was preceded by a breaking political story. 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
Checkout conversion was unchanged compared with the same hour of the previous week.
Recommendations
- Enable authenticated origin pulls.
- Enable log streaming to your SIEM for faster correlation.
- Add a dedicated rate limit for the targeted route.
Carpet bombing is nasty. Good to see a clear explanation of it.
Thanks! Yes — the risk score and its components are included in every log record.