Threat Bulletin 0257: GRE flood against a airline booking platform in Central Europe

On Thursday 17 February 2022 at 05:41 UTC, a GRE flood targeted a airline booking customer in Central Europe. The attack peaked at 275.6 Gbps and lasted 167 minutes. Traffic originated from 1274 autonomous systems in 28 countries, predominantly residential proxy networks.

Vector GRE flood
Peak 275.6 Gbps
Duration 167 min
Time to mitigation 0.024 s
Attack traffic reaching origin 0.058%
Legitimate traffic challenged 0.18%

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 13 points of presence.

What the customer saw

A brief increase in p99 latency of 159 ms during the first minute, then normal service.

Recommendations

  • Lower challenge thresholds on authentication endpoints during high-risk events.
  • Review allow-listed partner ranges quarterly.
  • Keep origin IPs out of public DNS history.

Leave a Comment

Your email address will not be published.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

Scroll to Top