I got the message "This site may be distributing malware. More details" on my Google Webmaster tools dashboard. The problematic URL is refering to "wp-includes/js/l10n.js?ver=20101110".

I notice two of my sites running wordpress was hacked. Google return a warning message "This site may harm your computer" on all URLs from both sites. You can check if your site is effected by typing "site:http://yourdomainname.com" at Google's search bar.

With Wordpress constantly upgrading and releases patches, hackers are turning to their attention to exploit on Wordpress plugins. Plugins that help the most people become their prime target.

Timthumb is an image resizer used by many theme developers around the world. As some Wordpress developers include a copy of Timthumb for ease of installation for their clients, problems came in when these older version were exploit by hackers.

Anyone using Wordpress with Timthumb, do make sure you upgrade your Timthumb to patch up the security loopholes found in earlier version.

Here is a site that explained in details how to clean up affected site. Fix this malware warning step by step