Hello..
I need to ask about something...
There is a visitor who keeps visiting my website through multiple proxies at the same time, but as you know.. most of proxy services pass the real IP in the requests.<p>And after his visits, a mysql db errors keep raising..<p>I need to know.. is it normal that a user visits a website through multiple proxies at the same time?
You are probably better off asking this somewhere like stackoverflow or severfault but it sounds like someone might be trying an sql injection attack. See if you can grab the url and querystring of the pages that are being visited
It's probably a botnet performing automated SQL injection checks on your site; you definitely need to make sure that you are correctly sanitizing any user input, especially if it's echoed back to the page (XSS) or used directly in a database query (SQL injection).<p><i>Especially</i> if you're having database problems, you're going to want to check things. If you have a database of accounts, you might even consider taking the site offline until you can verify that it is secure (and that it hasn't already been dumped to an attacker).