In order to remove Smashappsearch.com Search Redirect completely you will need to reset Chrome back to its initial settings. To reset Chrome, click on the Reset settings button as shown in the image above. Chrome will now erase all your personal data, browsing history, and disable all installed extensions. This process will also disable any installed toolbars and add-ons. All of your bookmarks, though, will be preserved and your favorites will still be accessible. To complete the reset process, you need to restart Internet Explorer and Firefox.
Source: https://www.bleepingcomputer.com/virus-removal/remove-smashappsearch.com-search-redirect