Searcher4u.com is a fake search engine that is being promoted by a browser hijacker application named PDFConverter4u. The application appears to be designed to spread among Mac users primarily.
Upon installation, the browser hijacker application begins generic traffic towards the promoted address and redirecting the user's searches by creating a LaunchAgent tasked with executing an AppleScript via shell script. In practice, this results in the AppleScript replacing any search query entered by the user through the Google, Yahoo, or Bing search engines with the one in the shell script - Searcher4u.com.
As we said, this search engine is classified as fake, and as such, it cannot produce any search results on its own. Instead, it would take the user's search query and redirect back to one of the legitimate search engines. In this case - search.yahoo.com.
Although it has not been confirmed if the PDFConverter4u application is capable of collecting private user information, it must be noted that the majority of browser hijackers do so. They can track the user's browsing activity, visited pages, search history, IP address, geolocation, etc. That is why it is strongly recommended to remove all adware or browser hijacker applications as soon as you notice the first signs of their presence.