Web Bypass Tutorial

In this tutorial I'll be showing you how to bypass a filtered network just by following some simple steps. Instead of using a proxy server that uses non-standard ports, I'll be showing you another expolit in an easier way. We'll use the expolit found in the URL mechanism itself. The ideas works as follows:

Converting the URL to an IP address and then to its binary representation or equivalent. This kind of exploit can be used commonly on Mozilla and Netscape. Enjoy bypassing websites at your college, though I don't hold any reponsibility on how you tend to use this information whatsoever.

Use at your own risk !!!

Keep in mind that there are two kinds of filtered network. There is the software and hardware side. In this tutorial we'll be introduing the software side of them.


Step 1: 

Get the IP address for the web site you need to bypass.

For example, undergroundsystems (Underground Systems) blocked in Web-content filtering software has this IP address: 72.29.78.187

I obtained the web domain IP address by pinging the site in command prompt console.


Step 2: 

Convert each individual number in the IP address to an eight-digit binary number.

Note: Numbers having fewer than eight digits in their binary form must be padded with leading zeros to fill in the missing digits. For example, the binary number 1 is padded to 00000001 by adding seven zeros before the number one.

Each IP address that uses IPv4, is a 32 bit binary number, therefore 4 bytes in total. So we need to convert each quad dotted binary number in the IP address to its binary number.

For each number:

72 = 01001000

29 = 00011101

78 = 01001110

187 = 10111011

The windows Calculator can automatically convert numbers from decimal to binary notation:

i. Choose View -> Scientific.
ii. Click the Dec option button.
iii. Enter the number in decimal value.
iv. Click the Bin option button to show the number in binary format.


Step 3: 

Assemble or group the four 8 digit binary numbers into one 32-digit binary number.

01001000000111010100111010111011

Note: Don't add the binary numbers. Just organize them in the same order as the original IP address without the separating periods.


Step 4: 

Convert the 32-digit binary number to a decimal number.

For example, the 32-digit binary number 01001000000111010100111010111011 is equal to the decimal number 1209880251.


The decimal number doesn't need to be padded to a specific length.

Step 5:

Plug the decimal number into the Web browser's address field, like this:

http://1209880251

Viola, the Web Page loads easy as pie!

Note: The preceding steps will not bypass URL's in Internet Explorer (though in some cases it still works).

Countermeasures.

If the bypassing of certain Web-content filters is an issue for your network, ask your content-filtering vendor if it has a solution for it :p


Happy Hacking