The chillsearch.xyz address belongs to a fake search engine. Users are highly unlikely to let such a search engine handle their search requests willingly. In fact, infosec researchers have observed that this particular address is being promoted via browser hijacker techniques performed by fake Adobe Flash Player installers.
After users execute one of these dubious installers, usually downloaded from a deceptive or hoax website, they will notice that the chillsearch.xyz address is now appearing in their Web browsers constantly. In most cases involving browser hijackers, the promoted address is set as the browser's homepage, new tab page and the default search engine. Because chillsearch.xyz lacks the necessary functionality to generate results on its own, it relies on another search engine - users will be shown results taken from Bing, a legitimate engine. Keep in mind that some fake engines could modify their behavior depending on specific factors.
Users also should be warned that while a browser affected by chillsearch.xyz is running, a potentially corrupted process named 'Searchie' will be active on the system. Users can search for this process via Windows' Activity Monitor tool.