Macro Virus

Macro viruses consist of instructions in Word Basic, Visual Basic for Applications (VBA) and other application macro languages. They often reside in documents or other file types that are traditionally thought of as ’just data’, and although that is not critical to determining whether something is a macro virus or not, it has been a crucial factor in the relative success of certain kinds of macro viruses. Another factor contributing to the success of macro viruses in the popular Microsoft Office application suite and related products (such as Microsoft Project) is that not only can the document files of these applications carry macro code, those macros can automatically run when certain basic events (such as opening and closing documents) occur and / or when the user expects that standard functions within the application should occur (such as selecting the Save item from the File menu).

While few users tend to think of ’documents’ as capable of being infected, any application which supports document-bound macros that automatically execute or usurp standard application functions is a potentially welcoming platform for macro viruses. By the late 1990s, documents had become much more widely shared than diskettes (assisted by the extensive adoption of networking technologies and particularly Internet e-mail) and document-based viruses dominated prevalence statistics. This seems likely to continue for the early years of the 21st century.

Updated On: 05.08.28