|Starting July of 2021, IS&T has migrated to a new version of Sophos called Sophos Central. MIT users have until the summer of 2022 before the old version will stop receiving updates. This page references the legacy version of Sophos. You can see documentation for the new Sophos Central here and download the newest version of Sophos here.
You may also need to grant full disk access.
Sophos Anti-virus requires approval of System Extensions by the end user before it's fully functional. On macOS 11 Big Sur, Sophos On-Access scanning will be disabled until you approve the Sophos System Extension.
After Sophos Anti-Virus installs you will see a prompt to open Security & Privacy in the System Preferences.
Go to the Apple Menu and select System Preferences->Security & Privacy
Click the lock icon in the bottom left if it is not already unlocked. You will be prompted to enter the password for an administrator account. Once unlocked, click the Details button, then check the two boxes for Sophos and click OK to allow the Sophos extensions. If the Details button doesn't show, follow the steps on approving kernel extensions.
When prompted to prompted, allow Sophos to add proxy configurations.
If you ar prompted to restart the computer, please do so to enable the Sophos System Extension. After restarting the computer, you can open the Sophos preferences and see that protection is enabled.
You may be prompted to approve Sophos components for Full Disk Access. See https://support.sophos.com/support/s/article/KB-000039014?language=en_US for details.