Microsoft granted a patent on a privilige escalation system which appears to cover the functionality of PolicyKit. PolicyKit is used for fine grain authorisation on Ubuntu, Fedora, openSUSE and other Linux systems. Patent claims in 7,617,530 appear to be for system software which, when an application needs a higher privilege level, displays a graphical list of users with the privileges required to perform the task. The issue affects default installations of Ubuntu Server and Desktop and is likely included in many Ubuntu-like Linux distributions.
Source: https://threatpost.com/new-ms-patent-may-put-linux-security-risk-111209/73086/