Disabling Directory Indexes will prevent visitors from seeing the contents of a directory when there is no index file present.
1) Log in to WHM and navigate to the following location.
Home » Service Configuration » Apache Configuration » Global Configuration
2) Uncheck the "Indexes" check box.
3) Click the "Save" button at the bottom of the page.
4) On the next page, click the "Rebuild Configuration and Restart Apache" button.