Apple has today pushed an update to Gatekeeper configuration data, which should have been silently installed on your Mac by now, or should be very shortly.
This brings it to version 137, with the update itself dated 21 February 2018. Apple doesn’t release any details of these updates, although this normally updates the data for recent signature revocations which have been used in malware.
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 and High Sierra, 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.