First, ensure to ALWAYS get WPP from codeplex website. Do not download from another site.
If you are sure that you have get this version of CustomUpdateEngine from Codeplex website, click on the link "Report the file as a false positive" and provide the EXE to Avast company for analysing.
If you are sure that you have get this version of CustomUpdateEngine from Codeplex website, click on the link "Report the file as a false positive" and provide the EXE to Avast company for analysing.