Unknown file

Avast Mac Security
1

Hello,

I have a file named FillSet.apxl appearing in download file of my macbook.It duplicates when I restart the computer naming it FillSet.apxl2 then FillSet.apxl3 …, even if I delete all the elements it reappears.
Does anyone know what it is and how can I delete definitely ?
Thanks

2

The extension is from Apple’s xml format used by Keynote (amongst other things).
Open it in a simple text editor and see if you can find out more about by looking at the content.