Macros are a powerful way to automate common tasks in Microsoft Office and can make people more productive. However, macro malware uses this functionality to infect your device.
How macro malware works
Macro malware hides in Microsoft Office files and are delivered as email attachments or inside ZIP files. These files use names that are intended to entice or scare people into opening them. They often look like invoices, receipts, legal documents, and more.
Macro malware was fairly common several years ago because macros ran automatically whenever a document was opened. However, in recent versions of Microsoft Office, macros are disabled by default. This means malware authors need to convince users to turn on macros so that their malware can run. They do this by showing fake warnings when a malicious document is opened.
We've seen macro malware download threats from the following families:
How to protect against macro malware
Make sure macros are disabled in your Microsoft Office applications. In enterprises, IT admins set the default setting for macros:
- Enable or disable macros in Office documents
Don’t open suspicious emails or suspicious attachments.
Delete any emails from unknown people or with suspicious content. Spam emails are the main way macro malware spreads.
Enterprises can prevent macro malware from running executable content using ASR rules
For more general tips, see prevent malware infection.