Malicious Mobile Code

What Is a Macro Virus?

A simple macro is series of steps that could otherwise be typed, selected, or configured, but are stored in a single location so they can automated. For example, you could use a Word macro to close typed letters. When you hit Alt-N, the macro could add two linefeeds, type in “Sincerely,” another linefeed, inserts your scanned signature and a linefeed, and then your typed name. An Alt-N macro could save a lot of time and effort.

Some software programs are nothing but hundreds of macros built around a vendor’s application. The macros take an otherwise general product, and customize it for a particular use. My first business accounting software package was nothing more than dozens of Lotus 1-2-3 macros controlling a large spreadsheet.

Many programs, such as Word, allow you to record a series of keystrokes and menu selections and then save them to a file. Although nifty, creating a macro one keystroke at a time doesn’t make for fast or sophisticated application development. Macro languages are used to allow more sophisticated macro development and environment control. Screens can be manipulated, users can be prompted for input, and nested if-then statements add functionality. Macro languages allow a developer to manipulate and create files, change menu settings, import and export data, and much more.

A macro language is a programming language, but it has its drawbacks. First, and most obvious, it cannot run without the underlying application. This leads into ...