As of 1st of January 2016 Microsoft requires SHA256withRSA digital signatures for executable files running on Windows 7, Windows 8 and Windows 10. Code signing certificates bought before year 2015 support only SHA1withRSA and you need a more recent code signing certificate in order your application to be allowed by the Windows Smart Screen filter.
More information here: http://zabkat.com/blog/code-signing-sha1-armageddon.htm
Microsoft advisory on TechNet: https://technet.microsoft.com/en-us/library/security/2880823.aspx
Software, Internet and related 