Apple has just pushed an update to the data files used by XProtect, bringing its version number to 2108, dated 13 November 2019.
Apple doesn’t release information about what this update adds or changes. Comparing this with the previous version, the only change apparent is the addition of three new items which are detected, cryptically named MACOS.de444f2, MACOS.b70290c and MACOS.22d71e9.
You can check whether this update has been installed by opening System Information via About This Mac, and selecting the Installations item under Software.
A full listing of security data file versions is given by SilentKnight, LockRattler and SystHist for El Capitan, Sierra, High Sierra, Mojave and Catalina, available from their product page. If your Mac has not yet installed this update, you can force an update using SilentKnight, LockRattler, or at the command line.
I have updated the reference pages here which are accessed directly from LockRattler 4.2 and later using its Check blog button.
I maintain lists of the current versions of security data files for Catalina on this page, Mojave on this page, High Sierra on this page, Sierra on this page, and El Capitan on this page.