Thursday, September 3, 2009
New AppLocker from MS - Some improvements
A was reading this article about AppLocker, the application control system from Microsoft that runs on Windows Server 2008R2 and Windows 7 clients. There seems to be some very good improvements there, specially the "automatic rule creation" part.In, short, an organization can build its "gold image" desktop, with all necessary apps, and run the automatic rule creator to identify all the applications that will be on the whitelist of things that can run on the desktop. If you are mature enough to have a real good "gold image", that shouldn't be very hard to do.The issue that I can see is with patches and updates. However, the automatic rule creation can work with the Publisher information when the binaries are signed, making it easier to accept new versions for those files. I think I'll try that in a lab to see how effective that is.Another interesting thing is that you can enable it in a "Audit only" mode. I have a personal view for whitelist based controls that is deploying them to generate logs only and monitor using a SIEM or similar system. On that way the risk to disrupt the environment is reduced and the exception can be managed on two levels (changing the whitelist, ignoring speficic alerts from the controls). It is one of the best ways to do security without breaking everything and also getting more value from a SIEM deployment. Be aware, however, that the SIEM system alone will not perform any miracles, this concept can only work when you have people and processes in place to deal with the generated alerts and to constantly tune the rules. That's the price to pay for more flexible security.