CyberSitter, CyberPatrol, SurfWatch, Net Nanny, I-Gear, SmartFilter, WebSENSE, BESS, X-Stop, NetRated and SafeSurf are among the most popular Web blocking applications available on the market. Those applications try to block users from reaching certain web sites.
Can those applications really block users from reaching prohibited web sites? Anti-censorship groups offer ways to bypass the blocking softwares, and expose the weaknesses that can help bypass those applications.
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For more information about anti-blocking software and why people are helping in defeating it, visit PeaceFire:http://www.peacefire.org/
For instructions on how to disable the leading web blocking software: http://www.glr.com/nurse.html
Web blocking software generally comes in three forms: an installation on the user's computer, using a proxy that filters URLs and as a module that integrates with a Firewall.
Local Installation
The local installation is the weakest of those three forms. It is generally hard to limit users from accessing their local computer. Even FoolProof, which is a software that its sole purpose is to limit users from free access to their local computer, can be easily overcome (see our article: Can FoolProof block malicious users?)
PeaceFire (www.peacefire.org) lists simple ways of disabling the most common web blocking software. Here is a short list of how to disable some of those applications:
CYBERsitter '97
Rename the file c:\windows\system\wsock32.dll to something like wsock32.bak
Rename the file c:\windows\system\wsockc97.dll to wsock32.dll
Other ways of disabling Cyber Patrol:
* rename the files c:\patrol\cyber.bin and c:\patrol\cyber.not
* create an empty file called cyber.not in the cyber patrol directory, restart windows and restart windows again. After the second time CyberPatrol will be disabled.
* Remove CyberPatrol from windows startup (by removing it from win.ini, the start menu and the registry)
* This program will temporarily disable Cyber Patrol: http://www.glr.com/cypatrol.zip
SurfWatch
An application called SurfPass will replace the master password with another known password. This program can also change the password back to the original to make itself un-noticed: http://www.peacefire.org/download/surfpass.exe
Net Nanny
* Kill the application by doing CTRL+ALT+DELETE, choosing Wnldr32 (on some versions the task is called OCRAWARE) and clicking "end task".
Proxy
Another method used by web blocking software is going through a proxy which filters the incoming URLs. A proxy is better than a local installation, because the user does not have full access to it.
However many anti-censorship are trying to fight this method of blocking by supplying an "anti-proxies". These are special web sites that allow a user to type in a URL, and receive the content of that URL, without actually doing the request for the URL. This "fools" the proxy filtering mechanism, since the user is communicating with an "allowed" site. A well-known examples of an "anti-proxy" service is the anonymizer: http://www.anonymizer.com/3.0/index.shtml
Another service that helps to bypass proxy filtering, is the web-page-by-mail service. Sending mail to: web@glr.com with the first line of the message being the requested URL, results in a reply containing the wanted web page. Google offers a cached version of many web pages, and this can sometimes be used to bypass web blocking software.
