Recently I put some hidden links in a web site in order to trap web crawlers. (Used CSS visibility hidden style in order to avoid human users accessing it).
Any way, I found that there were plenty of HTTP requests with a reference of browsers which have accessed the hidden links.
E.g : "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.64 Safari/537.31"
So now my problems are:
(1) Are these web crawlers? or else what can be?
(2) Are they malicious?
(3) Is there a way to profile their behaviour?
I searched on the web but couldn't find any valuable information. Can you please provide me some resources, or any help would be appreciated.