OSX/InstallImitator is a Potentially Unwanted Program (PUP) download manager, "installCore installer for Macs" by ironSource. The installer is used to deliver Adware and other Potentially Unwanted Programs (PUPs) to the infected computer, often imitating installers for widely used applications [1].

References:

1. https://www.sentinelone.com/2015/02/02/osx-ironcore-a-or-what-we-know-about-osx-flashimitator-a/