Blocking iphiding sites

Hi Everyone,

In my Redhat linux 9 system, I am using Squid as proxy. Using
squidguard I used to block the unwanted sites. But some users are
still accessing the blocked sites using some
Iphiding sites(example: hideme.com).
Apart from blocking the ip hiding sites, is there any other way to
stop the users from accessing the blocked sites.

Is there any ports I can block ,
which is used by the iphiding sites. Any specific ports are used by
them?


Thanks in advance

I don't know how you would do it in Squid, but we use SafeSquid for
proxying and content filtering, and this is how we can do it in
SafeSquid. Maybe you can find a parallel solution.

There are multiple methods of blocking access to unwanted sites in
SafeSquid:

1. Keyword Filter:
SafeSquid can analyze and identify the category a website belongs to
in real-time, by looking for specific words and expressions contained
in the meta tags, title and body of a web page. A list of the words
and expressions, usually found in the web page of the category of site
that you want to block, is defined and alloted a score. SafeSquid
calculates the total score of the words found in a web page, and if
the total score exceeds a defined threshold limit, the page is
identified as belonging to an unwanted category and blocked.
Detailed description for keyword filtering can be viewed from
http://www.safesquid.com/html/viewtopic.php?t=2007

If users try to access a website that is blocked by Keyword Filter,
through an external anonymous proxy or tunnel proxy, SafeSquid's
Keyword Filter will still be able to block it, since the total score
of the site remains the same. Such proxies can be used to bypass URL
Filters, but cannot bypass Keyword Filters.

You can also add Keyword Filter rules for identifying anonymous proxy
sites, and block access to them.

2. URL Blacklist:
We use the URL Blacklist database from http://www.urlblacklist.com ,
to block users from accessing unwanted categories of websites. They
offer more than 70 categories. One of the category is 'Proxy' which is
a database of websites with proxies to bypass filters.

Hope this helps you.

Regards.