Threat Bulletin 1239: SYN flood against a developer platform platform in Central Europe

On Friday 21 November 2025 at 16:41 UTC, a SYN flood targeted a developer platform customer in Central Europe. The attack peaked at 83.4 Gbps and lasted 89 minutes. Traffic originated from 3682 autonomous systems in 72 countries, predominantly a rented booter service.

Vector SYN flood
Peak 83.4 Gbps
Duration 89 min
Time to mitigation 0.403 s
Attack traffic reaching origin 0.039%
Legitimate traffic challenged 0.51%

Timeline

The attack was preceded by a competitor’s product launch. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 22 points of presence.

What the customer saw

Checkout conversion was unchanged compared with the same hour of the previous week.

Recommendations

  • Enable log streaming to your SIEM for faster correlation.
  • Enable authenticated origin pulls.
  • Lower challenge thresholds on authentication endpoints during high-risk events.

5 thoughts on “Threat Bulletin 1239: SYN flood against a developer platform platform in Central Europe”

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top