I can't find the link now. It's a SQL injection attack using vulnerabilities in Windows IIS for which there is NO fix. Most of the current attacks are eminating from Russia.
Irony is if you do a google search for nihaorr1 then all the infected websites are listed (122,000+ entries) as their SQL injection is picked up and displayed by Google in the header. Many seem to be travel websites, obviously to get payment details on reservations.