Does not workif using cf, create a waf rule -> select user agent, enter urlumbrella, then block or managed challenge
I only see that traffic in AnalyticsThere are 2 things here, that could be implemented depending on the platform your blog runs on:
1. Do you identify that traffic based on user agent or provider? Are you logging the traffic at your site level?
2. Depending on that, you can add a simple php script to redirect unwanted traffic to a 403 page for instance.