WordPress Virus?

Dear all,

Please kindly take a look on this case as it may have a large affect on WordPress Community.

When seeking for the way to make a Twenty Ten Child theme, I surfed some website and follow their tutorial then I can make a child theme (See more: du hoc my). But there was something so strange in my function.php as my theme was automatically add the code below:

[code moderated] Use a pastebin please.

I don't know why and how it can add into my theme, but It seemed to be harmless so I ignored it (I am really an amateur in coding). I uploaded my theme and used. Recently, I found that all of my 170 themes' function.php get infected the same code and some of themes turned to be errors. I have kept deleting those code but it still re-infect. It has driven me mad!!!

Please kindly take a look on this code and see it for what purpose and advise me how to get rid of it.

Thank you very much.