Fix Joomla error on ALL 7 my joomla sites

I have a infected server with malware so the last freelancer has told me and was unable to fix the error on all my 7 websites. I need someone to fix the issue and find how the malware is spreading and stop it. I need my websites back up and running ASAP. Whoever fixes this can be rest assured they will also be used for future work as I often hire alot. example of error shown can be found on homepage of url [login to view URL]