I have a client that found unauthorized, hidden anchortext links inside their site content.

After further research, I found several thousand sites that have this black hat hack with the commonality of being DNN sites.

The inserted scripts vary slightly, yet have the basic format:

Powered by cheap web hosting providers

Designed by XXXX web design services

Ways to make money online click here to try it out

Looking for great deals on cash for gold opportunities, Click here its risk free

I'm curious to know if...

• (a) this is simply a known hole in DotNetNuke security that is being hacked by someone on a mass scale,
• (b) if this hole can be closed - and at what level (site, page, global), and
• (c) if this security hole has been documented anywhere so that I can understand how to explain it to my clients.

Thanks for any input,
Brian

PS.  Another script example I found from another such site - as follows:

Powered by cheap web hosting services

speaking of cheap, try this cash for gold opportunities, its great!

* EDIT: Removed links

Thanks for your response.

As I am management (haven't been a developer for years, and am not the developer for any of these sites), the version used by each site is unknown to me.

I was made aware of it by a client who wanted assistance.  The pattern I recognized was a series of hidden links that have been published in such high volume to DNN-developed sites that it appears to be a security hole in older versions perhaps that haven't been patched yet.

Understood. As none of these are my sites, I'll advise my client to get the DNN code corrected. As far as the black hat SEO abuse, I'll report the code pattern to Google and let them de-list sites as they see fit according to their terms of service. Thanks for your input, Brian