avast normally only reply if they require more information.
Did you zip and password protect the sample ?
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 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.
The detection in the System Volume Information, is less of an issue as this is usually a file which has previously been deleted from one of your system folders (possibly malware) and system restore has save it in a restore point. If however, you used system restore in the future it could establish it again.
I would normally suggest you confirm the detections using multi engine scanners.
You could also check the offending/suspect file at:
VirusTotal - Multi engine on-line virus scanner and report the findings here. I feel virustotal is the better option as it uses the windows version of avast (more packers supported) and there are currently over 30 different scanners.
Or
Jotti - Multi engine on-line virus scanner if any other scanners here detect them it is less likely to be a false positive.
Whichever scanner you use, you can't do this with the file in the chest, you will need to move it out.