On Tuesday 9 April 2024 at 21:20 UTC, a ACK flood targeted a retail banking customer in Latin America. The attack peaked at 325.6 Gbps and lasted 123 minutes. Traffic originated from 3032 autonomous systems in 47 countries, predominantly a rented booter service.
| Vector | ACK flood |
| Peak | 325.6 Gbps |
| Duration | 123 min |
| Time to mitigation | 0.880 s |
| Attack traffic reaching origin | 0.015% |
| Legitimate traffic challenged | 0.69% |
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 30 points of presence.
What the customer saw
No customer-visible impact. The on-call engineer was notified and acknowledged the incident from the dashboard.
Recommendations
- Review allow-listed partner ranges quarterly.
- Add a dedicated rate limit for the targeted route.
- Lower challenge thresholds on authentication endpoints during high-risk events.
Carpet bombing is nasty. Good to see a clear explanation of it.