There are many 'different variants' of these fake alert/rogue programs and they need samples to analyse and include.
Send the sample to virus@avast.com zipped and password protected with the password in email body, a link to this topic might help and undetected malware/rogue in the subject.
Or you can also add the file to the User Files (File, Add) section of the avast chest (if it isn't already there) 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. Send it from the User Files section of the chest (select the file, right click, email to Alwil Software).
This process has been modified in the latest version to make it easier, it doesn't actually get emailed, but transferred when the next avast auto (or manual) update is done.