Google found the keyword on these top pages:

Google Webmaster Tools is one of the most usefull thing for every webmaster to check their site for malicious activities. Just recently I found a “viagra” on top keywords on my site and this affect the performance of my pages in Google ranking. I immediately resolved it using the Webmaster Tools provided disagnotics tools and Labs resources. Here is what I did.

1. Login to Google Webmaster Tools.
2. On the Dashboard, on Keywords area, clicked on the malicious keyword. It will display links where it finds those unwanted keywords.
3. Copy one of the link.
4. Go to Labs and Fetch as Googlebot.
5. Paste the link and view the results.
6. I found the invisible links that contains unwanted keywords and it was displayed at the very bottom of the page.
7. Went to my templates and found a script that is causing this invisible links and removed them.

I just found out that my website just been hacked and is cloaked so that only Googlebot sees these links. Regular browser won’t see it and it really requires tools to find them.