Site infected with malware

-- www.husbilskompisar.se/webshop/
-- HikaShop [1308281641]
-- Joomla! 2.5.14
-- PHP version -- : 5.3.3
-- Browser(s) name and version -- : All

We have a problem!

When we run sitecheck.sucuri.net/results/www.husbilskompisar.se/webshop/
we get the following results, what can we do?
Known javascript malware.
Details: sucuri.net/malware/entry/MW:SPAM:SEO
t='';}}x[l-a]=z;}document.write('<'+x[0]+' '+x[4]+'>.'+x[2]+'{'+x[1]+'}</'+x[0]+'>');}dnnViewState();