Macro viruses are computer viruses that use an application, such as a word processor’s programming language, to distribute themselves. A macro virus is often be difficult to detect and can be spread through email attachments, discs, networks, modems and the Internet.
Macro viruses commonly infect computers by replacing normal macros, or command keys, with the virus. Replacing the regular commands with the same name and running when the infected command is selected, the macro is opened without the user knowing. When a macro virus is triggered, it will begin to embed itself in other current and future-created documents and templates.