It seems that exe to swf conversion is mainly related to export of Flash Projector (.exe) executables to the original Flash source (.swf).
How to convert Flash Projectors files to SWF
In case your executable (.exe) is indeed a Flash Projector file made using some Flash tools or exported by Adobe Flash CC export as Projector function, you can potentially convert them back to swf with several dedicated utilities, such as the EXE to SWF Extractor, or similar. In case your .exe does not contain Flash graphics, it simply won't work.
Mac users can use Elmedia Player Pro, as it also should offer tools to convert exe to swf with just a few clicks.