Client's trash filling with large files after downloading and opening PDF

Hi all. 

I have a client for whom I've recently put together a number of various print pieces. When viewing two specific pieces (event programs created in InDesign and exported to PDF for print), my client and their employee are finding that their trash cans are filling with folders that are "website files", and that these folders are quite large and causing extreme slow downs. 

I am not able to reproduce this on my end. I suspect there's something going on with files I've linked to within the INDD — the folders being created within the trash can are the same name of the folder on my machine that holds those linked files. These linked files were created by someone in Publisher. 

Is this something anyone else has experienced? My client is becoming increasingly irritated, understandably, so any ideas or a solution would be appreciated.