When you double-click a Word attachment to open it, Word is started. When you double-click a picture file, a picture editor such as Microsoft Office Picture Manager is started. If the attachment is something that was created by a malicious person, all manner of bad things can happen when you double-click it.
Attaching files and pictures to e-mail is convenient. You insert a file or a picture, and you're done. It's a quick and easy way to share a wealth of information. Unfortunately, this convenience also makes it easy for unscrupulous users to share bad things — things like viruses or worms. Sometimes just the presence of a picture in a message can allow someone to have access to your private information without your knowledge.
Why there's potential for problems in attachments
In order to open an attachment, another program must be started so that you can view the contents of the attachment. For example, to open a Microsoft Office Word document, the Word program is started. Often, it's that action of starting a program that creates an opportunity for mischief. Attached files can also contain macros or other code that can harm your computer.
Why there's potential for problems in pictures
Another chance for mischief occurs when you view or download a picture in a message. When you do this, there's the potential that you could at the same time be sending information that you don't intend to send. You could be putting yourself in harm's way by simply looking at a picture. That's pretty frightening.
This all sounds very troublesome. Luckily, Outlook has a number of safety measures in place to help protect you. And there are steps you can take on your own, too. That's what we'll talk about next.