Recently I started to have spikes in organic traffic coming from baidu to one particular page of my site.
First of all, my site has a Chinese version and I do need visitors from China. So I don't want to block baidu completely.
Ok, I started to investigate. The average session duration for 90% of these hits is 0 seconds, so my guess is that these are not real visitors.
I started to gather the statistics for this page with PHP variables $_SERVER['REMOTE_ADDR'] and $_SERVER['HTTP_REFERER'] and here are the results (for the last two days):
Total IP addresses count = 3876
Unique IP addresses count = 3118
Maximum hits from one particular IP address = 9
Total http_referer = 3586
Unique http_referer = 3278
Maximum number of the same referral page = 5.
The problem is that the referral pages seem to be valid pages. They look like this: https://www.baidu.com/link?url=uQ3Foy5eYozYEq1wDKYDUqlbF_W-umpEZAMyulIp-MqiVUqPPdFUtT5_Xumavs7gKlfnZXv15-2H69EbcOkWbnXQua97JF4R45zzMO10LJY5yHlIxC2fZa-dX6JeMtLDut3VWu08nrbzFVt0XjgI5_&wd=&eqid=faceb5600002fa4d00000002585c8f6e
It's encoded address as it would appear in baidu search results and it redirects to the page in question.
Anybody has any ideas why this is happening and what can I do about it?
P.S. Since a long time I have a filter in GA to block all other hostnames except my own site.
UPDATE 1: Info on HTTP_USER_AGENT (for the last 24 hours):
Total http_user_agent = 1804
Unique http_user_agent = 607
The most frequent user agents count:
Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36 => 125 hits
Mozilla/5.0 (compatible; Baiduspider/2.0; +http://www.baidu.com/search/spider.html) => 108 hits
Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36 => 81 hits
Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.108 Safari/537.36 2345Explorer/220.127.116.1152 => 56 hits
Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.108 Safari/537.36 2345Explorer/18.104.22.16852 => 50 hits