On Thursday 8 June 2023 at 16:09 UTC, a ACK flood targeted a electronics retail customer in Central Europe. The attack peaked at 113.9 Gbps and lasted 125 minutes. Traffic originated from 1928 autonomous systems in 44 countries, predominantly a headless-browser farm.
| Vector | ACK flood |
| Peak | 113.9 Gbps |
| Duration | 125 min |
| Time to mitigation | 0.936 s |
| Attack traffic reaching origin | 0.023% |
| Legitimate traffic challenged | 0.58% |
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 40 points of presence.
What the customer saw
The customer’s status page stayed green throughout; they learned about the attack from our notification.
Recommendations
- Enable authenticated origin pulls.
- Add a dedicated rate limit for the targeted route.
- Lower challenge thresholds on authentication endpoints during high-risk events.