Its a legit Apple process. Since it appears you have a proxy, it must be getting hung up on it. SpotlightNetHelper is related to how Yosemite and up now send information to Apple about Spotlight searches and location data. See this article: http://www.cultofmac.com/300301/keep-os-x-yosemite-sending-spotlight-data-apple/

You can follow the steps outlined to disable these functions, or you can try using the python script linked to in the article to automate disabling this feature.