This technique uses a script that opens a legitimate Web site in the background, while a spoofed pop-up window, usually identical to the legitimate Web site, is opened in the foreground. In effect, this misleads the user into thinking that pop-up window is directly related to the official page. In some cases, the pop-up window covers a portion of a legitimate Web site. Popular applications that support macros (such as Microsoft Word and Microsoft Excel) are the most common platforms for this type of virus. These viruses are written in Visual Basic and are relatively easy to create. Macro viruses infect at different points during a file's use, for example, when it is opened, saved, closed, or deleted.