I have recently had random spam links inserted into 3 ASP.NET websites. The links are inserted into the physical file so it is not SQL injection attack.
The websites have very little in common other than they are ASP.NET, 2 of them are MVC and 1 is webforms, 2 are c# and 1 is VB, etc.
The server is Windows 2003 with IIS6 and all security updates have been installed. FTP was turned off overnight and an attack still occurred.
Any ideas on how to start troubleshooting this?
EDIT: Turns out the latest updates have not been installed (last update was June 2010) so I'll need to install all of those first before investigating further.
EDIT 2: Latest updates installed and problem has yet to reoccur. Chalk one up for keeping your server up to date.