title: Why does Google Chrome sometimes warn that a downloaded PDF can harm your computer?
body: <p>We have a web site that makes several PDFs available for download. The PDFs might be static, or dynamically generated. They are downloaded using one of several mechanisms (static-URL, post back/redirect/meta-refresh/etc.). For certain PDF files, Chrome downloads them without complaint. For others, it warns the user that "This type of file can harm your computer.  Are you sure you want to download ..." and requires an extra click.</p>
  
  <p>What information is Chrome using to decide whether to show the message? Obviously, it's not simply the fact that the file is a PDF.</p>
  
  <p>To be clear, I want to do something on the server side (we use IIS/ASP.NET, if it matters) to prevent the message from ever appearing. I'm not interested in a solution that has each user disable the message in their browser (if that's even possible).</p>
  
  <p>Thank you.</p>