What is the Challenge Page?
The visitors of any website are divided into 3 types:
Human Visitors: Does not need an explanation since here we mean human visitors!
Unharmful Crawlers: Like the crawlers of Google, Bing, Alexa and others.
Malicious Crawlers: Crawlers that enter websites to check for the presence of any security hole, to be used in spreading spam, injecting the pages with viruses, even DoS attacks is done by malicious crawlers.
The challenge page is coded for this type of visitors.
According to the Security Level you set in CloudFlare settings, the service will check the incoming connection to your website, in case any of these connections were malicious crawlers or something similar the visitor will be blocked, to enter the site the visitor should type the CAPTCHA in the related box and press “REQUEST ACCESS”, for sure if it was malicious crawlers it will not be able to enter the website and so the site is protected against this type of visitors.
In some cases this page appears to human visitors, this is due to the presence of viruses in the visitor’s computer, to protect the site the challenge page is displayed to the visitors and he/she needs to enter the CAPTCHA, this is to make sure that the visitor is the one who wants to visit the site not the virus which done this automatically (according to the virus code). The page also advice the visitor about the importance of checking his/her computer and make sure of getting rid of the viruses that could steal his/her sensitive data.