Firewall Reporting Random Files (*.txt and non-executable files) Trying to Access the Internet

Hi  My Norton Firewall, running under OSX 10.10.5, occasionally report some unusual files trying to access the Internet including personal *.txt and *.doc files.  This seems very odd to me and I wondered if the system is infected and requires the re-installation of the OS.  Also, Norton often does not start when the system is rebooted.  Is there anything to worry about?  (I've come across a similar forum thread in 2013, and wonder if there is already a solution for this and why the thread was closed.)  Thanks.