On Saturday 23 May 2026 at 14:52 UTC, a UDP reflection (NTP) targeted a healthcare portal customer in the UK. The attack peaked at 6.6 Gbps and lasted 102 minutes. Traffic originated from 2201 autonomous systems in 85 countries, predominantly compromised cloud VMs.
| Vector | UDP reflection (NTP) |
| Peak | 6.6 Gbps |
| Duration | 102 min |
| Time to mitigation | 0.408 s |
| Attack traffic reaching origin | 0.054% |
| Legitimate traffic challenged | 0.76% |
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 19 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.
- Add a dedicated rate limit for the targeted route.
- Keep origin IPs out of public DNS history.