Just after pushing its earlier update to Gatekeeper’s data, Apple has just pushed an update to its malware removal tool, MRT, for macOS, bringing its version number to 1.42.
Apple doesn’t provide any information on what changes this update brings. As it now obfuscates the names of malware which it can detect and remove, it appears impossible to correlate changed strings in the app with any malware known outside Apple.
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.