On Tuesday 23 April 2024 at 20:17 UTC, a ACK flood targeted a electronics retail customer in Southeast Asia. The attack peaked at 93.5 Gbps and lasted 125 minutes. Traffic originated from 2917 autonomous systems in 29 countries, predominantly a headless-browser farm.
| Vector | ACK flood |
| Peak | 93.5 Gbps |
| Duration | 125 min |
| Time to mitigation | 0.224 s |
| Attack traffic reaching origin | 0.055% |
| Legitimate traffic challenged | 0.23% |
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 21 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.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Keep origin IPs out of public DNS history.