Microsoft Windows Media Center MCL URL File Disclosure Exploit (MS15-134)

Windows Media Center MCL files can specify a URL to be automatically loaded within Media Center. A specially crafted MCL file can abuse this URL parameter in order to trick Windows Media Center into rendering the very same MCL file as a local HTML file within the application's embedded web browser. This way, attacker-controlled Javascript code can run in the context of embedded IE's Local Machine Zone with no security prompts, since Media Center does not opt-in for the Local Machine Zone Lockdown policy. This can be leveraged by an attacker to read and exfiltrate arbitrary files from a victim's local fileystem by convincing an unsuspecting user to open an MCL file. This module will try to steal a couple files that should be present on every vulnerable machine (the mshta.exe executable from the Windows\System32 folder and the WindowsUpdate.log file) in order to confirm the existence of the vulnerability. The module can be configured through the "Files to retrieve" parameters group to try to steal a predefined set of important user files from the Google Chrome and Mozilla Firefox web browsers (such as the Cookies, History, Preferences and Bookmarks files), and the Mozilla Thunderbird email client (address book, preferences, emails). However, note that web browser's History files and Thunderbird's email databases can be pretty big; in those cases, Windows Media Center can get stuck for minutes while trying to read those files. In order to steal Chrome/Firefox/Thunderbird files, the MCL file needs to infer the location of the %USERPROFILE% folder (typically something like C:\Users\JohnDoe) by inspecting its own current path. That means that stealing files from the %USERPROFILE% folder will only work if the MCL file is opened from a path under the %USERPROFILE% folder in the victim's machine, such as the Desktop, the "My Documents" folder, or the "Downloads" folder. The "Files to retrieve" parameters group also accepts a text file containing a custom list of files to be retrieved from the target system. Retrieved files will be saved to the folder specified in the OUTPUT FOLDER parameter. The module will create a separate folder for every compromised target.