Hello Ander,
In order to improve the Foxit Reader / Foxit Cloud experience, we've eliminated the need for extra background processes that were required to run Foxit Cloud as a plug-in to Foxit Reader. By doing so, Foxit Reader (and Foxit Cloud) see better performance in the way of processing and memory usage, as well as overall resource allocation.
To disable Foxit Cloud, you can do the following:
1) Go to File -> Preferences
2) Select Foxit Cloud on the left-hand column
3) Then select the option to "Disable cloud tab"
4) Click OK
5) Go to Help tab, then select "About Foxit Plug-Ins"
6) Select Foxit Cloud Login
7) Click the crossed out circle icon to disable
8) Click OK
Sincerely,
Team Foxit Cloud