Mass SQL Injection Attack Hits Sites Running IIS
blog.sucuri.net
blog.sucuri.net
So it's really SQL injection attack hits sites running crappy custom code.
Neither SQL server nor IIS are at fault here.
The article just states a couple of IIS sites got compromised again. It's not blaming IIS for that.
And SQL injection is not completely platform independent: your database must support SQL for it to work.