If your browser’s address bar searches are redirecting through smashapps.net, you have an unwanted extension or add on installed. These extensions perform the redirects in order to track your searches and generate revenue from advertising. The developer is utilizing Yahoo as they may earn revenue from the advertisements that are displayed in the Yahoo search results. To remove this extension and other unwanted programs for free, you can use the removal guide below. You can see an example of the smashappsearch.net redirect below.
Source: https://www.bleepingcomputer.com/virus-removal/remove-smashapps.net-search-redirect