Reader warns you any time you try to open a URL (web link) or a file attachment that uses a disallowed file type. URLs and disallowed file types (for example, EXE) are potentially dangerous because they can transfer or run programs, macros, or viruses that can damage your computer.
You can allow Reader to contact specific websites by adding those URLs to your list of allowed websites in the Trust Manager preferences. Remove any URLs you no longer want to visit. To open file attachments in Reader, you must respond to a prompt by indicating that you always allow files of that type. The attachment