Board Thread:Questions and Answers/@comment-5422312-20121230230240/@comment-5590118-20130103052754

It trips it because it interprets the page as an executable file much like adding the .js extention to any page makes the server render the contents of that page as javascript, adding .exe makes the server try and execute the code (it does this but there is no result) but if you add the coding for a real malicious .exe then it will execute it and it will become a problem.