How to remove a virus detected in my forum HTML/Rce.Gen

[samergains]

Hi everybody,
my forum is infected with a virus called HTML/Rce.Gen
it looks like only the home page is infected but i'm not sure. i'm getting a warning message from the anti-virus only on the homepage.
by viewing the source code of the homepage I found a javascript block added after the end of the html code.

any ideas about finding the infected files in my forum?
is there any method to remove the virus from admincp?
here is a link to give you some details about the virus:
http://www.threatexpert.com/report.a...7f16a20c7b351a

--------------- Added [DATE]1320228975[/DATE] at [TIME]1320228975[/TIME] ---------------

i found the javascript block in 'FORUMHOME' template and deleted it.
Now it's working fine but i'm not sure this is enough to protect my forum.

any suggestions for more security?