If you have a sample of the malware then it can be sent to avast for analysis.
Send the sample to virus@avast.com zipped and password protected with the password in email body and undetected malware in the subject.
Or you can also add the file to the User Files (File, Add) section of the avast chest where it can do no harm and send it from there (select the file, right click, email to Alwil Software). No need to zip and PW protect when the sample is sent from chest. A copy of the file/s will remain in the original location, so any further action you take can remove that.