Fences does not 'inject' anything into FF.  Fences runs in the Windows Explorer process only - which is pervasive in Windows so I suspect that is what it's seeing (and totally benign). 

Sean Drohan
Stardock Support Manager

This is normal for applications which impact system wide things.  Sometimes hooks have to be set which can only be system wide with no ability to filter it for process names.

A dll being in process is not cause for concern in this case and it will simply do nothing in the firefox process as it is not explorer.  The list is not a list of software which modifies Firefox, it is purely a list of dlls loaded into the memory space which are not signed by Microsoft or Mozilla.

The WB one is entirely unavoidable as WB loads into everything.  Otherwise it wouldn't work.  The only difference is WB isn't MS signed unlike the MS theme engine.

This is the problem with a feature that lists dlls without any context.