The University requires that all computers connected to the University's network via Ethernet or Wi-Fi be using up to date anti-virus software.
Apple macOS computers are susceptible to malware and viruses, so this requirement holds true for Mac users.
Learn more about anti-virus software at UD.
For personally owned, non-UD systems
There are several free anti-virus packages for macOS. UD recommends Avast for personal computers that are not owned by UD.
You can download the software from the Avast website.
Follow the directions at the Avast site to install, set up automatic updates, and use the software.