Here is a starting point for IP address to block.
I would very much like it if Solarwinds followed and implemented changes that the Forums come up with. However given I have seen messages that are 8 years old and I still do not see the requested features added I doubt that this will happen. I could give adjectives to describe Solarwinds, but what would be the point.
This post is to help the community that uses Serv-U and would like to increase there security by blocking a few IP addresses.
Best of Luck,