A macro can quickly run a sequence of steps and commands that otherwise could be time consuming.
So what are macros, and how do they affect you?
A macro is a quick way of carrying out a number of steps. It's a small program written to automate the steps. Instead of going through a series of commands manually, you can automate them by running a macro. For example, you can use a macro to enter dates rather than typing them every time, or to carry out mathematical processes on a subset of the data in a worksheet. They are fantastic time savers, and very useful things. Macros can be saved as part of a Microsoft Office document in Word, Excel, PowerPoint, or Access.
Why does this matter? Because macros are little pieces of code, and therefore they could potentially contain a virus. Of all the security risks you may encounter in Microsoft Office documents, macros are by far the most likely. Therefore, it's great news that the 2007 Office release detects macros and disables them.
ActiveX controls and add-in programs
Another way that viruses can get into your Office documents is through ActiveX controls and add-in programs. Like macros, ActiveX controls and add-in programs are usually useful, but they also can be used for malicious purposes. As potential security risks, they will also trigger the security warning in the Message Bar and will be disabled, and you'll have the chance to enable them if you want to.