Apple has released an update to XProtect for all versions of macOS, bringing it to version 5344. Version 5343 doesn’t appear to have been released. As usual it doesn’t release information about what security issues this update might address.

This version makes minor amendments to the Yara rules for MACOS.SHEEPSWAP.OBF.C, MACOS.SHEEPSWAP.OBFE.COMMON and MACOS.ADLOAD. There has been no change in the Osascript rules in XPScripts.yr.

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 and SystHist for El Capitan to Tahoe available from their product page. If your Mac hasn’t yet installed this update, you can force it using SilentKnight or at the command line.

If you want to install this as a named update in SilentKnight, its label is XProtectPlistConfigData_10_15-5344

Sequoia and Tahoe systems only

This update has already been released for Sequoia and Tahoe via iCloud. If you want to check it manually, use the Terminal command
sudo xprotect check
then enter your admin password. If that returns version 5344 but your Mac still reports an older version is installed, you should be able to force the update using
sudo xprotect update