Don’t forget if you do happen to find something not detected by avast! (with your enhanced security), then if you can zip and password protect (‘virus’, will do) the suspect file and send it to virus @ avast.com (no spaces).

Give a brief outline of the problem, the fact that you believe it to be a new/undetected virus and include the password in the body of the email. Some info on the avast version and VPS number will also help.