You can use mail
send to virus@avast.com in a password protected zip file
mail subject: False Positive / undetected sample (select subject according to your case)
zip password: infected
As it is PUP or Riskware for Confuser Packed as a Generic Detection, you could ask for a review of the detection.
In that case report to virus@avast.com and mentioned the used obfuscated packer that might have been detected as probably malign.
There should be a avast team member considering the FP if any.
We are volunteers only here, so we can only signalize issues.