Just updated stat to version 20.  After a few senior moments got everything working fine.  Decided to add the plugins. Well things seemed to have gone just fine. Downloaded the files, unzipped them and uploaded to my site. Set permissions for a few of the files and then....................got a message that the files couldn't be found?  They had to be, I could see the icons for them!  Typed in the addy for them and the file folders showed up.  Well when I clicked on the folders a number of the functions showed "cron_function.php.infected" or some other function or page with "infected". What to Do? Never had this happen before. Doubt very much the Zip file was at fault.

There is definitely a webserver security module in place that is alerting and renaming the desired files. Please contact your hosting provider and ask for the reason. It's not a normal behaviour of the plugin files.