I am not sure if my question is appropriate to ask here, apologies in advance but I am confused and need some helpful thoughts!!

We was using this Plugin for our site https://github.com/wp-plugins/wp-rss-multi-importer

But this plugin got removed from Plugin Repo as this post suggest along with alternative http://www.wpmayor.com/wp-rss-multi-importer-removed-from-plugin-repo/

But alternative is very expensive and out of budget for our use.

My site recently got hacked and hackers put some Casino link in some other plugins including this Plugin.

Is this should be vulnerable plugin without security updates ?

Please suggest !! Thanks :)