To get a macro virus, all you need to do is double-click on an infected document, to view it. When it loads the macro runs and you're PC is infected. Because macro viruses are written in a macro language, a given macro virus will run in any environment which can understand and interpret those macro instructions. Thus the Word. However, English versions of Word are available in the Macintosh, DOS, Windows, Windows 95 and 98, and Windows NT operating systems, so this virus can infect on all of these platforms.
Macro viruses are always application-specific.
Word Macro viruses will only infect Microsoft Word. This is of little comfort to those who are already infected or to those who have one of these popular packages, but it should provide assurance to those folks who are using something else. A macro virus consists of a set of macros, nothing more. The macros must be stored wherever the application stores macros. In the case of Word, macros are stored in templates rather than documents.