Safe.search.tools is a new hijacker currently infecting various widely used browsers. The purpose of this program is to generate profit for the people who develop it and who own it. You may notice that when you make certain query via safe.search.tools the search results will be obtained through Google Custom Search, which is run by one of its Google Adsense partners. So, obviously the goal of this hijacker is to bring income to the guys who are the proprietors of this application.