How do macro viruses work?
Macro viruses gain access to word processing and spreadsheet files by attaching themselves to the executable portion of the document – usually replacing the AutoOpen, AutoExec, AutoNew, AutoClose, AutoExit macro commands Macro viruses are particularly difficult to eradicate because they can hide in attachments to old e-mail messages. For example, a network once infected by a macro virus can become re-infected when an employee returns from vacation and opens an old e-mail attachment with a virus. When the employee forwards it to others on the network, the virus can spread again, necessitating a second round of detection and disinfection.
