On Tuesday 12 December 2023 at 04:25 UTC, a ACK flood targeted a developer platform customer in Western Europe. The attack peaked at 296.0 Gbps and lasted 25 minutes. Traffic originated from 3977 autonomous systems in 8 countries, predominantly residential proxy networks.
| Vector | ACK flood |
| Peak | 296.0 Gbps |
| Duration | 25 min |
| Time to mitigation | 0.677 s |
| Attack traffic reaching origin | 0.048% |
| Legitimate traffic challenged | 0.44% |
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 22 points of presence.
What the customer saw
The customer’s status page stayed green throughout; they learned about the attack from our notification.
Recommendations
- Review allow-listed partner ranges quarterly.
- Enable authenticated origin pulls.
- Add a dedicated rate limit for the targeted route.