I have similar problem about the domain that has been hi-jacked and they placed links [to adult content and pills] on our pages.
This domain is a sub-domain using as a community forum where people can sign up and join the community and we use community server platform to operate the forum. We also have a link to this sub-domain out from our main site homepage as well.
On 20th July, we found hundreds of new pages under our sub-domain listing in Google serps and having Title for something like...
"[product] - our brand name" or
"Order [product] online - our brand name"
Normally it should be "Member name - our brand name", so we think it could be some auto generated software that perform the auto registration with those keywords as an account name.
Actually the site was inactive for a while but Sign-in and Join function were still working as we were missing to disable them because we didn't think something like this was going to happen.
After click on the link in Google, it goes to a blank white page with 2 links in H1 says something like "Click Here For [product]" and "Buy Now" linking straight out to their site.
We checked on html code and found that actually our page are still there but they create a blank page with 2 links on the top of surface on our page.
Then it looks like our sub-domain is now linking to hundreds of bad neighborhood sites, so we immediately removed a link to this sub-domain from our main site home page.
We want to get rid of those listing in Google but unfortunately we didn't verify this sub-domain in GG webmaster tools so we can't request the domain removal in WMT. So now we took the site down showing 404 and block them in robots.txt hoping GG to slowly drop the page out of their index.
Is there any better idea to do apart from this? Appreciated any advice.
[edited by: tedster at 4:45 am (utc) on July 27, 2009]
[edit reason] remove specific spam products [/edit]