I have used theme from http://www.mage-world.com for my website. Firstly, the website operated well, but then the traffic decreased dramatically. It was just after several months since I bought the theme and it happened all of a sudden. After doing searching and analyzing, i found my website website is integrated with hidden text link within the theme, which was purchased from Magento-world. Therefore, I sent this warn to you all to be aware of themes of this supplier. Also, I list others websites which can be potentially the next victims.
Please check your site if you are their customer. So dangerous!
What they use: hidden text link in your site with this:
<p class="welcome-msg">Welcome! <div id="mw-reference">
Your world of <a href="http://www.mage-world.com/magento-extensions.html" title="Magento Extensions">Magento Extensions</a>,
<a href="http://www.mage-world.com/magento-extensions.html" title="Magento Modules">Magento Modules</a>,
<a href="http://www.mage-world.com/magento-themes.html" title="Magento Themes">Magento Themes</a>
and <a href="http://www.mage-world.com/magento-themes.html" title="Magento Templates">Magento Templates</a> by Mage-World.
Another Topics scam from Mage-world.com i got there: http://www.magentocommerce.com/boards/viewthread/232835/