On Tuesday 11 June 2024 at 23:08 UTC, a ACK flood targeted a municipal services customer in North America. The attack peaked at 366.0 Gbps and lasted 181 minutes. Traffic originated from 67 autonomous systems in 46 countries, predominantly mobile carrier ranges.
| Vector | ACK flood |
| Peak | 366.0 Gbps |
| Duration | 181 min |
| Time to mitigation | 0.667 s |
| Attack traffic reaching origin | 0.013% |
| Legitimate traffic challenged | 0.14% |
Timeline
The attack was preceded by an extortion email received two days earlier. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 25 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.
- Enable log streaming to your SIEM for faster correlation.
- Add a dedicated rate limit for the targeted route.
Would love a follow-up on how you handle HTTP/3 fingerprinting.
Clear and practical, thanks.
How do you avoid challenging uptime monitors and partners?
Machine-readable ranges are at /ips.json and via the API.
How do you avoid challenging uptime monitors and partners?