OsCommerce been hacked, viruses installed - Need cleaning!

We've been notified by customers that they are receiving threats from two quite serious viruses when visiting our store. What we need: - The viruses (as well as anything else that shouldn't be on our install) removed. - Increasing security (installing any mods that would help, renaming folders etc). - Whilst we're here we'd also like to make it so that regardless of what country customers are from, they can only view the English version of the site. Freelancer Requirements: - Native English speaker. - Must be willing to work through this weekend (1st - 2nd Sept), we need this project finished ASAP. - Preferably able to talk via MSN / Yahoo. We'll be leaving this project open for roughly 15 hours (til 1pm GMT 30th August). Thanks, we look forward to working with you!