Hackers are actively exploiting a vulnerability in WordPress.

Hackers have begun actively exploiting a vulnerability in the WordPress content management system. Using this vulnerability, hackers can flood Google Images search results with images that link to pornographic websites.

Experts discovered this vulnerability in more than 4,500 WordPress blogs.

Porn sites that appear in search results in this case attempt to trick users into installing fake antivirus software.

The vulnerability was discovered by Russian IT specialist Denis Sinegubko. He was unable to detect the algorithm used to infect WordPress blogs, but he determined that the blogs were being infected by the TimThumb extension.

More detailed technical information about the problem is available athttp://blog.unmaskparasites.com/2011/08/05/hacked-wordpress-blogs-poison-google-images/