Apple has pushed another Gatekeeper update

Apple has recently pushed another security update, once again to Gatekeeper’s configuration data, bringing it to version 128. This often occurs when it has revoked further developer signatures, in response to their misuse in malware, but Apple does not announce these updates, or explain what has changed.

If you want to check your current security update status, my free app LockRattler (from Downloads above) reports all the key version numbers, and I maintain lists of current versions here for Sierra, and here for El Capitan. When High Sierra is released, I intend to maintain lists for it and for Sierra.