"jQuery was clean"

The JavaScript you posted is not jQuery, it's a plugin to extend jQuery. As for the remainder of your post, sounds like you need to speak to someone who knows what they're doing from a computer security/administration perspective. If you system, server or network is compromised and you don't know how an iframe to a site which doesn't exist is the least of your problems.

...we have to 'clean' infected files (*.js, .htaccess etc)... some Perl codes will help us in such works ))...

Enough codes make shapes. (Hamidjon)

For all you know someone has root on your system, you may also be making any computer forensics more difficult by muddying the waters (in an activity perspective). Even if you didn't restoring from backup is the sensible solution rather than editing lots of files.