Virus in build 878

I have just down-loaded and unzipped build 878.
My virus checker (AVG) says that BlackBox.exe contains "Win32:SMorph[Cryp]", whatever that means.
Does anyone else have a similar problem; what is the solution?
My virus checker (AVG) says that BlackBox.exe contains "Win32:SMorph[Cryp]", whatever that means.
Does anyone else have a similar problem; what is the solution?