有的时候打开后台会发现网站后台有各种莫名其妙的蜘蛛UA，而不是搜索引擎来过的，那么可能是被别人给爬取了，可以用下面方法来屏蔽不明的蜘蛛UA，可根据网站实际情况来修改要屏蔽的蜘蛛UA
Nginx将以下代码加入到配置文件server里:

if ($http_user_agent ~ "MegaIndex|MegaIndex.ru|BLEXBot|Qwantify|qwantify|semrush|Semrush|serpstatbot|hubspot|python|Bytespider|Go-http-client|Java|PhantomJS|SemrushBot|Scrapy|Webdup|AcoonBot|AhrefsBot|Ezooms|EdisterBot|EC2LinkFinder|jikespider|Purebot|MJ12bot|WangIDSpider|WBSearchBot|Wotbox|xbfMozilla|Yottaa|YandexBot|Jorgee|SWEBot|spbot|TurnitinBot-Agent|mail.RU|perl|Python|Wget|Xenu|ZmEu|^$" )
{
return 444;
}

IIS7/IIS8/IIS10及以上web服务请在网站根目录下创建web.config文件,并写入如下代码即可:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<system.webServer>
<rewrite>
<rules>
<rule name="Block spider">
<match url="(^robots.txt$)" 
ignoreCase="false" negate="true" />
<conditions>
<add input="{HTTP_USER_AGENT}" pattern="MegaIndex|MegaIndex.ru|BLEXBot|Qwantify|qwantify|semrush|Semrush|serpstatbot|hubspot|python|Bytespider|Go-http-client|Java|PhantomJS|SemrushBot|Scrapy|Webdup|AcoonBot|AhrefsBot|Ezooms|EdisterBot|EC2LinkFinder|jikespider|Purebot|MJ12bot|WangIDSpider|WBSearchBot|Wotbox|xbfMozilla|Yottaa|YandexBot|Jorgee|SWEBot|spbot|TurnitinBot-Agent|mail.RU|perl|Python|Wget|Xenu|ZmEu|^$"
ignoreCase="true" />
</conditions>
<action type="AbortRequest" />
</rule>
</rules>
</rewrite>
</system.webServer>
</configuration>

IIS6请在isapi重写组件中添加以下规则:

#Block spider
RewriteCond %{HTTP_USER_AGENT} (MegaIndex|MegaIndex.ru|BLEXBot|Qwantify|qwantify|semrush|Semrush|serpstatbot|hubspot|python|Bytespider|Go-http-client|Java|PhantomJS|SemrushBot|Scrapy|Webdup|AcoonBot|AhrefsBot|Ezooms|EdisterBot|EC2LinkFinder|jikespider|Purebot|MJ12bot|WangIDSpider|WBSearchBot|Wotbox|xbfMozilla|Yottaa|YandexBot|Jorgee|SWEBot|spbot|TurnitinBot-Agent|mail.RU|perl|Python|Wget|Xenu|ZmEu|^$) [NC]
RewriteRule !(^/robots.txt$) - [F]

apache请在.htaccess文件中添加如下规则：

<IfModule mod_rewrite.c>
RewriteEngine On
#Block spider
RewriteCond %{HTTP_USER_AGENT} "MegaIndex|MegaIndex.ru|BLEXBot|Qwantify|qwantify|semrush|Semrush|serpstatbot|hubspot|python|Bytespider|Go-http-client|Java|PhantomJS|SemrushBot|Scrapy|Webdup|AcoonBot|AhrefsBot|Ezooms|EdisterBot|EC2LinkFinder|jikespider|Purebot|MJ12bot|WangIDSpider|WBSearchBot|Wotbox|xbfMozilla|Yottaa|YandexBot|Jorgee|SWEBot|spbot|TurnitinBot-Agent|mail.RU|perl|Python|Wget|Xenu|ZmEu|^$" [NC]
RewriteRule !(^robots\.txt$) - [F]
</IfModule>