On Wednesday 5 July 2023 at 12:18 UTC, a Slowloris targeted a sports betting customer in the Nordics. The attack peaked at 123.1 million requests per second and lasted 26 minutes. Traffic originated from 326 autonomous systems in 34 countries, predominantly a Mirai-derived IoT botnet.
| Vector | Slowloris |
| Peak | 123.1 million requests per second |
| Duration | 26 min |
| Time to mitigation | 0.280 s |
| Attack traffic reaching origin | 0.055% |
| Legitimate traffic challenged | 0.09% |
Timeline
The attack was preceded by a breaking political story. Request rates on the targeted routes exceeded their hourly baseline by a factor of 540 within 23 seconds. The risk score of participating clients crossed the challenge threshold automatically and proof-of-work difficulty rose with origin load.
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 log streaming to your SIEM for faster correlation.
- Review allow-listed partner ranges quarterly.
Solid runbook advice. The DNS-at-2am point hit home.
Solid runbook advice. The DNS-at-2am point hit home.
Interesting that most attacks are under ten minutes. Our experience is similar.
Clear and practical, thanks.
Machine-readable ranges are at /ips.json and via the API.
Solid runbook advice. The DNS-at-2am point hit home.
Verified good bots and allow-listed partners bypass challenges entirely.
Solid runbook advice. The DNS-at-2am point hit home.
Nice to read a vendor blog that admits what went wrong.
Nice to read a vendor blog that admits what went wrong.
This matches what we see in iGaming around big matches.