said by Simple Guy:At this point all I need to know is (please entirely forget about Sophos at this point) is how to use my Mac, (finder I presume) to navigate to where I can search or see hidden files. By doing that I can go to the location of the file and manually delete it.
If you have the full path in /folder/folder/folder form, then from any Finder window, go to the "Go" menu at the top of the screen and select "Go To folder". Put in the path (without the filename) and it'll take you to that folder even if it's hidden.
In general, Finder only hides files/folders that begin with a ".", but there are some special folders that are also hidden, such as /Users/you/Library and all of the system folders (/etc, /private, /var and so on).