Are you using AVG and avast antivirus at the same time in the same computer?
Can you say what is the infected file name, where was it found (C:\windows\system32\infected-file-name.xxx)?
Can you send the samples to virus@avast.com ?
You can zip and password the files... Inform a link to this thread and the password used.
You can send the files to Chest and, from there, resend to Alwil for analysis.
Thanks.