LSA service issues - error code 87 "Invalid parameter" RRS feed

  • Question

  • One of components of our application is dll implementing custom authentication package.

    It's main function is to start processes on behalf of local users. We noticed that this functionality breaks when lsass.exe process runs with PsProtectedSignerAntimalware-Light or PsProtectedSignerLsa-Light protection. In case of Antimalware protection, module is loaded by lsass.exe, but execution of process fails with error code 87 "Invalid parameter". With PsProtecedSignerLsa-Light, module is not even loaded by LSA service.

    We suspect that problem might be related to digital signatures.

    1. How to verify that problem comes from lacking/incorrect digital signature?

    2. In case of PsProtectedSignerAntimalware-Light, module is correctly loaded but execution of process fails. Does it mean that executable also requires some special signature in order to be correctly launched from protected LSA  service?

    Friday, March 31, 2017 2:16 PM