A macro is a series of commands that you can use to automate a repeated task, and can be run when you have to perform the task. Macros automate frequently used tasks to save time on keystrokes and mouse actions. Many were created by using Visual Basic for Applications (VBA) and are written by software developers. However, some macros can pose a potential security risk. A person with malicious intent, also known as a hacker, can introduce a destructive macro in a file that can spread a virus on your computer or into your organization's network.