Hi exile360 and many thanks for your reply - much appreciated.
Prior to receiving your comment, I did in fact restart my Windows 10 PC and tried a simple delete on the .exe file and it worked. It now sits in my Delete Folder presently. It did not ask for Administrator permissions either.
The little program, which has worked perfectly for a month or so, is called Bulkimageconverter.exe (71kb). I suspect it could well be a false positive, so I will do as you suggest and attach a 'zip' copy once I figure out how to manage that.
I have Malwarebytes v 3.8.3