Remote Assistance don't send mail with thunderbird RRS feed

  • Question

  • Hello,

    First, sorry for my poor english.

    I'm sure i'm not the only one guy with this issue. Old peoples that ask me for help and use thunderbird can't use thunderbird to send the file. It's difficult for old peoples to send to me the invitation file. Many of us doen't understand that they can use a webmal. And they can't find the file in their file system.

    Since some new versions of w10,  RemoteAssistance can't open the client SMAPI of thunderbird.

    I make trace/debugger session in W10-64bit-V19h1 ( i don't make trace with 20h2)

    I use windbg, procmon, ida and i see that LoadLibraryA  returns "ERROR_INVALID_IMAGE_HASH 577 (0x241) : Windows cannot verify the digital signature for this file". And it returns that because CI.dll detects a "wrong" certificat (a call to CI.dll!CipReportAndReprieveUMCIFailure, i see rapidely that in 20h2 the stack is different but issue is there).

    It seems that a new security level for RemoteAssistance was introduce in a "new" (2018/2019) versions of w10.

    RemoteAssistance uses a SMAPI dll, mozmapi32-inuse.dll  in the case of Thunderbird as client mail.

    This dll is well signed. But it seems that MS, for security reason, imposes a certificat with a "better" level and blocks other certificats when using RemoteAssistance ( msra.exe).

    But if I change the client\mail to "hmmapi.dll", the site html is open. But this hmmapi.dll seems to be not signed ( no digital signature in properties in explorer). Does it mean that OS doesn't check certificat for MS program ?

    Complex !

    I don't understand if the culprit is W10 or Thunderbird.

    If someone can test and explain how to use thunderbird with MSRA, i will be happy.

    Note : i don't need a workaround, i wrote a powershell script for "open msra/sending file" for the novices that i help.

    Friday, November 13, 2020 11:10 PM

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