I was busy on helping my friend to clean up the Trojans in his company website, it seems come from their company internal computer. It is already infected couple of weeks ago but I discovered it yesterday, they did not realize it is virus. The most common script redirect user to another website: martuz.cn, which is not a safe website.
I don’t have any backup files and I don’t know any better way to clean it, therefore I did clean it up by using UltraEdit “Batch Replace” to search and replace for patterns of Trojans Scripts.
The most important thing before you clean up Trojans: Make sure all computer linked to server is clean, otherwise you will have to clean it up again and again.