On Thursday 2 January 2025 at 21:26 UTC, a ACK flood targeted a retail banking customer in the Benelux. The attack peaked at 80.2 Gbps and lasted 11 minutes. Traffic originated from 3679 autonomous systems in 118 countries, predominantly a Mirai-derived IoT botnet.
| Vector | ACK flood |
| Peak | 80.2 Gbps |
| Duration | 11 min |
| Time to mitigation | 0.035 s |
| Attack traffic reaching origin | 0.056% |
| Legitimate traffic challenged | 0.06% |
Timeline
The attack was preceded by a publicly announced sales event. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 12 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 log streaming to your SIEM for faster correlation.
- Enable authenticated origin pulls.
- Keep origin IPs out of public DNS history.
Solid runbook advice. The DNS-at-2am point hit home.
Machine-readable ranges are at /ips.json and via the API.
Nice to read a vendor blog that admits what went wrong.
Verified good bots and allow-listed partners bypass challenges entirely.
Any plans to support per-tenant limits keyed on a JWT claim?