If you're on Windows 8 and experience an error with "WinVerify Trust failed on stub executable: WinVerifytrust failed with hrc=CERT_E_CHAINING on '\ProgramFiles\Oracle\VirtualBox\VirtualBox.exe" and Virtualbox 4.3.28, the workaround/solution that has worked with most efficiency has been uninstalling that version and using this one: Virtualbox 4.3.34 from this link. There is no specific reason given for the cause of this issue, however, the official Virtualbox Forums point to a possible false-positive with the internal Windows 8 security routines and 4.3.28.
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