hey and welcome to the forum.
you could upload the file to virustotal.com and post the result here so we can have a lock at it.
but what you describe it sound it could be a false thread.
to be one the safe side please follow this guide and attach you logs.
a malware expert will remove if something comes up in the logs.
http://forum.avast.com/index.php?topic=53253.0
good luck.