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I'm trying to make a website that displays the feedback from the Windows 10 Feedback Hub but i have met a roadblock. I'm using Fiddler 4 (Fiddler Everywhere doesn't have support for UWP yet and WireShark didn't give me much data) to see the requests being sent to Microsoft's servers. I have tracked down that the request that receives the feedbacks is the following:

GET https://uif.microsoft.com/FeedbackCloudService.svc/feedbacks?&language=en-US&sortCategory=0&searchCategory=1&feedbacksFilter=0&issueFilter=0&statusFilter=0&buildFilter=0&userFilter=1&filterFormFactor=1&isRefresh=False&hasSticky=False&useCol=1 HTTP/1.1

But this request require a Bearer token (not JWT) which changes each day. The token is never being received from any of the previous requests sent what i can gather so I assume it's being generated locally in the app. Example of what that token can look like:

Bearer t=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&p=

So now I wonder if there's any way to crack open the Feedback Hub app and see how this token is being generated or where it's getting it from. I know pretty much nothing about RE and especially not about UWP RE since it's not dotnet so I can't use dotPeek on it or similar. Any help would be appreciated!

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  • Do other Windows 10 apps use the same type of auth token? If so, I wouldn't look for token generating mechanism inside this particular app, I'd rather look for some global Win 10 api – Iks Ski Nov 22 '20 at 14:55
  • @IksSki Windows store seem to be using a similar auth token. Any idea where i could start looking for such an API? I thought if i could find where the Feedback Hub gets it's token from it might lead me to something? – Dar Nov 22 '20 at 17:00
  • try attaching debugger on Hub's process and look into "Symbols" window, here you'll have all of the .dll the process uses. Maybe you'll find something useful there (like network related libraries, etc). Another option may be searching for some unique strings like "FeedbackCloudService.svc" inside the .exe or one of its dependencies (dlls). Also, I think static analysis (with ghidra or ida) could be helpful, too – Iks Ski Nov 22 '20 at 18:14
  • @IksSki I don't seem to be able to see much with the VS debugger and I don't really understand the assembly code in IDA – Dar Nov 23 '20 at 21:34

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