The program I use to create my e-books produces an executable file (.exe). This is great for e-books because makes it possible to have stand-alone e-books that can run themselves, just like a web-site!

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Security Tip - Be Careful with Attachments:
Well, it's been another big year for hackers. There have been a number of  really bad viruses just within the past 6 months. We've seen the  W32.Beagle, W32.Netsky, MyDoom, and so on and so on. Most of these viruses  were transported or replicated from pc to pc using email attachments.  These are easy to spot if you're paying attention, simply because they are  usually executable files, but not always.
 
Some attachments contain Macros (simple programs that run within other  programs-all the titles in Microsoft Office use macros). If you're not  that familiar with spotting file extensions, don't worry, that's what I'm  here to talk about today. If your a little hazy on the whole "file  extension" thing then let's spend a few moments explaining it.
 
File extensions are what tell the program how to treat a particular piece  of data. For example, most people are somewhat familiar with .doc or a  .txt file extensions these are both text documents and when the user opens  this file the Operating System looks at this extension and then knows how to open it.
 
Hackers try to use some sort of eye-grabbing ploy to get you to open their  email and activate the virus which is always an attachment. Most  Anti-virus nowadays stop, or at least warn, you of these high risk  attachments and even take measures to protect you. However, on the average  10-15 new viruses are created every day and I personally wouldn't count on  any program to 100% protect my pc. That's why I scrutinize any email-if I wasn't expecting an attachment, I won't open it until I had a chance to  talk to the sender.