A few days ago we posted about a series of attacks that were happening against WordPress sites running the vulnerable timthumb.php script.
That is code is generated by an echo statement hidden within one of the WordPress core files and is always accompanied of multiple backdoors and even .htaccess redirections (to http://generation-internet.ru and other russian sites).
Both domains were registered by Archil Karsaulidze (probably fake) and are pointing to 188.8.131.52:
Archil Karsaulidze firstname.lastname@example.org
+74957261532 fax: +74957261532
Moscow Moscowscaya Oblast 107263
How are the sites getting compromised?
On the sites we’ve analyzed, they were hacked through the timthumb.php vulnerability that was published a few days ago. The attackers are also creating a bunch of backdoors to maintain their access to the hacked sites.
If you are using the timthumb.php scripts, remove or update it now!.
Keeping yourself secure
This is not a vulnerability in WordPress, it is a vulnerability found in various WordPress themes that include TimThumb! You have to make sure that you are using an updated theme, and from a legitimate source. Otherwise your theme may contain this vulnerability, or others (even backdoors), that may not be given the proper attention by their theme authors.
If you’re not sure, you can do a free scan of your site using Sucuri SiteCheck