404. That’s an error.
The requested URL /_/+1/confirm?hl=en&url=https://www.sans.org/course/defending-web-applications-security-essentials/Type/asc/training-event was not found on this server. That’s all we know.
/_/+1/confirm?hl=en&url=https://www.sans.org/course/defending-web-applications-security-essentials/Type/asc/training-event