[wp-hackers] Free themes have backlinks and backdoors inserted in code?

[Mayur somani]

Hi,

While researching on some of the, so called, black hat SEO strategies,
I found many tricks to insert backlinks and backdoors into free
wordpress themes and then distributing them.

Now this is unacceptible. So, please list any of the ways you know to
insert backlinks and backdoors into themes files. I am planning to
write a plugin that will scan all the theme files to report any
malicious code there.

Thank you for your time.