In the last 2 weeks, i've seen two machines which were brought to their knee's by a TON of rundll32.exe running in the background. I determined they were being caused by Webroot. In each case, webroot had just updated 1 day before. (judging by the installed date in the apps and features)
The first machine had 5,000+ rundll32's and the machine i Just saw this morning had 160. After uninstalling webroot from safe mode both computers ran normally.
Both machines were running Windows 10. I have neither computers in my possession so all I can do is report on the issues I've seen. I thought it was a one off the issue until I just saw it this morning.