[Angel-Wings]

Hmmm - what you write isn't right It's not that 3 sites on your shared server are infected - would be a very strange shared server being located in the US, Switzerland and France at the same time.
When calling your site, sniff the headers and you'll see - there're 3 sites loaded with PHP files which all point to the same location - another site from Russia.

Check the PHP files of your board by downloading them from the official location then comparing them with your files, also check the DB (e.g. Templates) from where these files are called. If and only if there's nothing, check it again and if there's still nothing then and only then Gigapros is the problem.
Just if you write you've been hit with malware, did you setup your board again or just let it be ? Chances are high the problem is somewhere in your files where these calls are stored.