For privacy and security reasons, it would be strongly recommended to deactivate the Flash plugin in the browser. But I don't want to deactivate it, I want to fake privacy relevant information. Companies can create a fingerprint about a user. The Flash plugin serves much information, like:
- installed fonts,
- IP-address (original one behind a proxy) or
- the used OS and kernel system / version
So my question is:
Is it possible to fake such information and how?
When I use for example Firefox, does Firefox serve these system information for the Flash plugin and then I can fake them with a Firefox addon which registers the call event of the Flash extension and returns wrong data? Or has the Flash plugin direct access to the operating system? If yes, can I build software which runs in the OS background and registers the Flash plugin call and then serves faked information?
I know that NPAPI is the interface between the browser and the OS, but I have no idea if it is possible to manipulate the called information in any way and if such information (like installed fonts) are parameters stored in the browser or served by the OS.
Original data: Windows 8.1, Firefox 24, English language, 23 fonts installed
- Step: i call a random website with flash fingerprinting tool
- Step: the tracking tool starts to collect my fingerprint with flash, calls action script functions to get installed fonts etc.
- Step: through the action script functions, the Flash plugin tries to get the information from Firefox or OS (NPAPI)
- Step: Before the flash plugin calls the data from Firefox or OS, my own developed firefox addon, which is installed, detetct and catch the event, prevent the system call and returns instead of the original data, spoofed data (OSX, Firefox 24, English language, 12 fonts installed) from my firefox addon
Result data for Flash plugin: OSX, Firefox 24, English language, 12 fonts installed
At 4. step i want to spoof system parameter. And the question is, if this is possible in general (with a Firefox extension or a OS native application) and how. And: from where does the Flash plugin get the system information? From Firefox parameter? Through the NPAPI interface from the system?