The virus which infects the specific type of document created using the certain application that contain macro such as Ms-Word, Ms-Excel, spreadsheet is known as macro virus.
- Programs like Ms-Word, Ms-Excel support user defined macro. A macro is a series of commands and actions that help to automate some tasks. Uninfected documents contain normal macros. Most macros start automatically when a document is opened or closed. A common way for a macro virus to infect a computer is by replacing normal macros with the virus. The macro virus replaces the regular commands with the same name and runs when the command is selected.
Examples: DMV, Nuclear, word concept etc.