On Wednesday 29 March 2023 at 06:40 UTC, a memcached amplification targeted a retail banking customer in Iberia. The attack peaked at 85.3 Gbps and lasted 53 minutes. Traffic originated from 2920 autonomous systems in 76 countries, predominantly a rented booter service.
| Vector | memcached amplification |
| Peak | 85.3 Gbps |
| Duration | 53 min |
| Time to mitigation | 0.445 s |
| Attack traffic reaching origin | 0.029% |
| Legitimate traffic challenged | 0.17% |
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 33 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.
- Review allow-listed partner ranges quarterly.
- Enable authenticated origin pulls.
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.
Would love a follow-up on how you handle HTTP/3 fingerprinting.