On Thursday 2 September 2021 at 16:44 UTC, a memcached amplification targeted a video streaming customer in the Nordics. The attack peaked at 236.1 Gbps and lasted 86 minutes. Traffic originated from 2503 autonomous systems in 103 countries, predominantly a headless-browser farm.
| Vector | memcached amplification |
| Peak | 236.1 Gbps |
| Duration | 86 min |
| Time to mitigation | 0.422 s |
| Attack traffic reaching origin | 0.013% |
| Legitimate traffic challenged | 0.63% |
Timeline
The attack was preceded by a ransom note demanding payment in Monero. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 38 points of presence.
What the customer saw
Checkout conversion was unchanged compared with the same hour of the previous week.
Recommendations
- Enable authenticated origin pulls.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Enable log streaming to your SIEM for faster correlation.
Clear and practical, thanks.
The billing model is what got our finance team on board, honestly.
Thanks! Yes — the risk score and its components are included in every log record.
How does the proof-of-work challenge behave on older Android devices? Any numbers below Android 10?
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.
Thanks — sharing this with our on-call team.