On Thursday 21 April 2022 at 15:02 UTC, a memcached amplification targeted a municipal services customer in the Nordics. The attack peaked at 254.7 Gbps and lasted 156 minutes. Traffic originated from 1218 autonomous systems in 83 countries, predominantly a rented booter service.
| Vector | memcached amplification |
| Peak | 254.7 Gbps |
| Duration | 156 min |
| Time to mitigation | 0.237 s |
| Attack traffic reaching origin | 0.056% |
| Legitimate traffic challenged | 0.73% |
Timeline
The attack was preceded by a hacktivist channel announcing the target. 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
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Enable log streaming to your SIEM for faster correlation.
- Review allow-listed partner ranges quarterly.