One of the most common ways that bad guys sneak malware onto your computer is through macro-enabled Excel files.

A macro (short for macroinstruction) is a set of commands that automate a process in Excel. When you open an Excel file that includes macros, you’ll see a security banner with the option to activate macros by clicking “Enable Content”.

Typically, malicious Excel files are attached to a phishing email. If you choose to open the attachment and enable macros, the file will automatically install the cybercriminal’s malware.

In a recent phishing attack, the macro-enabled Excel attachment is designed to look like a Windows Defender help page. The spoofed help page provides easy-to-follow instructions on how to click the “Enable Content” button. To establish additional credibility, the file includes logos of well-known security vendors like McAfee.

If you fall for this trick and enable macros, a dangerous piece of malware is installed onto your computer and cybercriminals will have complete access to your system.

Follow these tips to stay safe:

• Never download an attachment from an email that you weren’t expecting.
• Don’t let your eyes deceive you. Bad guys use familiar logos from real businesses to appear more legitimate.
• Before enabling macros for an Excel file, contact the sender using an alternative line of communication – such as by phone or text message. Verify who created the file, what the file contains, and why macros are necessary.
• Stop, Look, and Think. Don’t be fooled.