Once you are in Safe Mode download and run the shareware app Find Any File to search for any files with the application's or the developer's name in the file name. For the StatefullFirewall software you'd do the following search(es):
1 - Name contains statefullfirewall
Any files that are found can be dragged from the search results window to the Desktop or Trash bin in the Dock for deletion.
FAF can search areas that Spotlight can't like invisible folders, system folders and packages.
You may have installed or tried unknowingly to install some malware. Also while in Safe Mode download an run the free version of download and run the free version of Malwarebytes to verify that you've gotten all the aware/malware removed. It was developed by a long time contributor to these forums and a highly respected member of the computer security community.
