On Thursday 2 February 2023 at 15:30 UTC, a ACK flood targeted a online payments customer in the Benelux. The attack peaked at 145.6 Gbps and lasted 108 minutes. Traffic originated from 3205 autonomous systems in 31 countries, predominantly mobile carrier ranges.
| Vector | ACK flood |
| Peak | 145.6 Gbps |
| Duration | 108 min |
| Time to mitigation | 0.649 s |
| Attack traffic reaching origin | 0.090% |
| Legitimate traffic challenged | 0.65% |
Timeline
The attack was preceded by a breaking political story. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 23 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
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Enable authenticated origin pulls.
- Review allow-listed partner ranges quarterly.
How does the proof-of-work challenge behave on older Android devices? Any numbers below Android 10?
Nice to read a vendor blog that admits what went wrong.
Could you share the dataset behind the percentages?
Nice to read a vendor blog that admits what went wrong.
How do you avoid challenging uptime monitors and partners?
Thanks! Yes — the risk score and its components are included in every log record.