A code on top of my page

Everything seems to be working but there is this code shows up in the topleft corner throughout my website:

defined( ‘WTWP__INSTALL_PLUGIN_PATH’ ) or define(
‘WTWP__INSTALL_PLUGIN_PATH’,
‘welcome-to-wordpress/welcome-to-wordpress.php’ );

function install_wtwp()
{
global $pagenow;

if ( !( ‘install.php’ == $pagenow && isset( $_REQUEST )
&& 2 == $_REQUEST ) ) {
return;
}
$active_plugins = (array) get_option( ‘active_plugins’, array() );

// Shouldn’t happen, but avoid duplicate entries just in case.
if ( !empty( $active_plugins ) && false !== array_search(
WTWP__INSTALL_PLUGIN_PATH, $active_plugins ) ) {
return;
}

$options = array(
‘first_login’ => false,
‘plid’ => 1,
‘isc’ => ‘WPHosting1’,
‘api_url’ => ‘https://wpqs.secureserver.net/v1/’,
‘help_url’ => ‘https://help.securepaynet.net’,
‘control_panel_url’ =>
‘https://hostingmanager.secureserver.net/Login.aspx’,
‘key’ =>
‘3YbIMU+Dq6a8SN57B3ta+3JuMv8itLKVSsxt+VizcSKuvVov/AoT+78WfyRI7Ui1’
);

$active_plugins[] = WTWP__INSTALL_PLUGIN_PATH;
update_option( ‘active_plugins’, $active_plugins );
update_option( ‘wtwp_options’, $options );
}

add_action( ‘shutdown’, ‘install_wtwp’ );

I already disabled all plug-ins