We need an application that will block access to certain sites

Project Description:
Requirements to the program:
1) Internet traffic analysis with ability to block access to the URL
- by full URL
- by the name of the site
- by keywords

2) Without connection with specific browser

3) Operating Systems:
Windows XP 32-bit and 64-bit
Windows 7 32-bit and 64-bit
Windows 8 32-bit and 64-bit

4) Technology:
intercept WinAPI-functions (DLL), driver

5) Programming Language:
any, but we should be able to manage functionality of this program from Delphi application

6) Running without administrator rights (user level), tolerance from anti-virus software

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To demonstrate the functional:
We need a Delphi application with
- field to enter an URL
- buttons: "block", "unblock"

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As a result of the work we need a functional source code.

Additional Project Description:
03/19/2013 at 22:06 AKDT
Do not add records into HOSTS file!