Click on report as false positive and fill up the details. You can also email them virus at avast dot com

Subject as “False Positive” with out quotes.

Or you can go directly here https://www.avast.com/contact-form.php?subject=VIRUS-FILE

Another way is by going to Avast Support Ticket via here https://support.avast.com/ On the left hand side click on Avast Virus Labs. Remember this, once you submit a support ticket about a false positive. It can take 5-7 days for a reply back. DON’T reply back to your own support ticket or it will be pushed back into the line. First come first serve basis. So be patience.