On Friday, January 22nd starting at approximately 2:47 PM PST, Pantheon experienced malicious load-generating traffic that caused resource exhaustion on a portion of Pantheon’s redundant infrastructure to have some uptime impact on 10% of customer sites. Pantheon engineers began mitigations shortly after the malicious traffic was first observed, and all sites were operating normally by 3:47 PM. 

Pantheon has identified and begun work to prevent this specific type of malicious traffic from causing platform degradation in the future.