Four different websites got infected and been blocked by Google, and after a quick look, I've noticed this just before wp_head():

echo(gzinflate(base64_decode("tVVNj5swEP0... (edited out) hH5m7L/5+/gM=")));
wp_head(); ?>

I have cleaned the code but this reappeared after a few hours. Then again and again. I thought that timthumb is the culprit, but this happened on a WordPress without timthumb aswell as I've scanned it previously with timthumb vulnerability scanner.

There's nothing suspicious in htaccess, wp-config and the files everyone is talking about, from wp-includes, have checked all the js files, nothing, nothing, nothing.

What could it be, how do I get rid of this?

closed as off topic by Chip Bennett, Wyck, fuxia Apr 21 '12 at 16:41

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  • 2
    Terribly sorry to hear that your site is infected. Unfortunately, questions regarding recovering from site hacks are explicitly out of scope for WPSE. – Chip Bennett Apr 21 '12 at 14:32
  • I know, but I was thinking this is a bit different. I kind of need any info on this, I can do everything by myself, I only need a hint or two as I have been doing everything possible to fix this. – Chris Apr 21 '12 at 14:40
  • Read the question and answers Ray Mitchell recommended. We couldn't add more anyway. – fuxia Apr 21 '12 at 16:41
  • I've had similar issues. Be sure to scroll to the bottom of the files you mentioned you checked. The hacks are tricky and add a lot of "returns" or blank space after the normal code and where the offending code exists. – Jeremy Jared Apr 21 '12 at 19:05
  • It seems to be something related to a security hole in WP 3.3.1. Apparently a lot of sites have been affected. – onetrickpony Apr 21 '12 at 19:15

Sorry to hear. You may want to look through the steps and suggestions in this WP Answers post: Verifying that I have fully removed a WordPress hack?

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