I had some malicious javascript appended to my .js files on a website and tracked the hack in my logs to an old FCKEditor exploit.
As a relative novice, I've been reading up a bit on how this was done and how I can protect against it, but I have a few specific questions, listed below.
If it's helpful, this was Windows Server 2012, IIS 8 and SQL Server, and, I'm embarrassed to say it, but this was an old site still running Classic ASP. Here are my questions:
I had IUSR as my Anonymous User in IIS. When the hacker uploaded the .asp file to get shell access, I assumed they only had the privileges conferred to them via IUSR, correct? If the server is properly hardened, they can't escalate privileges to get more access than what IUSR has, right?
I've changed my Anonymous User to be the application pool identity. Since a hacker's grab-shell-access ASP program now won't have IUSR's privileges and will only have the application pool identity, is it safe to assume that they can't get the ability to run commands like WHOAMI or any other such commands? What rights would application pool identity (and thus any of my .asp programs that serve up web pages) have?
Last question. OK, so I clearly was giving IUSR too much power on this box, given that an anonymous user for IIS could run a .asp program and get shell access. So how do I query what privileges IUSR has across the entire computer? I know I can, for example, right click on my inetpub folder and look a security to see what IUSR can do, but is there a way to get a report across the entire server to understand the full rights and privileges for that particular user.
My focus with these questions is more about general learning than about protecting this box. I'm sure some might be inclined to say your box is probably toast and backdoored, so dump it and start with a new server, but I know that. I also know that I should have done some hardening that I didn't. Thanks for your answers to questions above, which will help me learn and improve. Much appreciated.
1.IUSR will determine what identity you are using to view your web page and also application pool identity will decide whether the application or shell can be executeed. So you need to minimize permission for both app pool identity and iusr.
2.By default application pool identity don't have permission to access something like powershell or cmd. So you don't have to afraid command like whoami will be executed.
3.I'm afraid there is no simple way to do permission traversal. But you just need to make sure you have already minizized your application pool identity permission.