On Monday 13 March 2023 at 15:20 UTC, a UDP reflection (DNS) targeted a retail banking customer in Western Europe. The attack peaked at 383.1 Gbps and lasted 62 minutes. Traffic originated from 3327 autonomous systems in 56 countries, predominantly a rented booter service.
| Vector | UDP reflection (DNS) |
| Peak | 383.1 Gbps |
| Duration | 62 min |
| Time to mitigation | 0.360 s |
| Attack traffic reaching origin | 0.023% |
| Legitimate traffic challenged | 0.47% |
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 33 points of presence.
What the customer saw
Checkout conversion was unchanged compared with the same hour of the previous week.
Recommendations
- Keep origin IPs out of public DNS history.
- Enable log streaming to your SIEM for faster correlation.
- Enable authenticated origin pulls.
Nice to read a vendor blog that admits what went wrong.
Thanks! Yes — the risk score and its components are included in every log record.