I use winverifytrust to validate signature.
I am verifying using WINTRUST_ACTION_GENERIC_VERIFY_V2. But rarely it has returned "NO SIGNATURE FOUND". I am unable to simulate the issue.
I am getting feedback that this is happening in some users. One feedback has a log which indicates that the 1st call to WinVerifyTrust for a file succeeds and the second call to the same file has failed.
The code i used is exactly
http://msdn.microsoft.com/en-us/library/aa382384%28v=VS.85%29.aspx
Any idea what may have caused the failure. Same call to the same file has succeeded once and failed next.