Apple has just pushed an update to the ‘Yara’ data files used by XProtect, bringing its version number to 2101, dated 11 December 2018. This is the second minor update to XProtect in over eight months, which merely raises the minimum usable version number of Adobe Flash Player to 188.8.131.52. It makes no changes at all to malware detection signatures.
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 LockRattler and SystHist for El Capitan, Sierra, High Sierra and Mojave, available from Downloads above. If your Mac has not yet installed this update, you can force an update using 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.
For those using the latest version of LockRattler (4.18), you should see its new red text feature at work: when you have installed the update, click on the Refresh button, and the installation details will be updated and displayed in red. If you then close LockRattler and open it again, you’ll see the XProtect version number in red, indicating its recent update.
I confess that I breathed a deep sigh of relief when I saw this new feature working for the first time on a real update.