I found the same virus on my Joomla website and found this info:
File Name: http//:geonon.net/in.php
Malware Name: HTML:Iframe-MD(Trj)
Type: Trojan Horse
I deleted the code you mentioned above from my index.php page and cleared all caches in Joomla but the virus is still showing up. Please update this thread as you get more information. I will be watching for a fix.
I hope this doesn’t count as hijacking another topic. It is the same problem and it is confusing to have several topics on the same issue.