Apple has just pushed an update to XProtect Remediator security software for Macs running Catalina or later, bringing it to version 65.
Apple doesn’t release information about what this update adds or changes. This update doesn’t add any more executable code modules, so presumably updates one or more of them.
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 to Ventura available from their product page. If your Mac has not yet installed these updates, you can force them using SilentKnight, LockRattler, or at the command line.
I have yet again experienced problems with my Content Caching Server delivering an update which won’t install properly. If you’re running your own local server, you may find you have to turn it off before you can get this update to install successfully.
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 Monterey on this page, Big Sur on this page, Catalina on this page, Mojave on this page, High Sierra on this page, Sierra on this page, and El Capitan on this page.