I searched for Oliverto here in the Forum and got a few hits on Oliverto Search since late May, some of which definitely implicated InKeepr (formerly Genieo). They also have a web site (oliverto[dot]com) that reads, in part:
Oliverto Installer is a delivery and installation platform (âOlivertoâ) which performs and optimizes the installation of software applications (the "Software") developed and/or published by independent software vendors (âISVsâ). During installation, We may offer you to install additional softwares (the âOffersâ or âAdditional Softwaresâ), developed and/or published by other ISVs. In addition, We may offer you to change your homepage or your default search provider. You may decline any of our offers, including The Offers, and may decide to cancel the installation.
The "Reset Search" app is actually supposed to be the uninstaller app for all this, but if it works as previous versions it will leave things behind or perhaps even install something new.
The instructions for changing the Safari home page lead you to an Apple KB document. Their instructions for changing the Safari search provider leads back to a posting in this forum.