The latest version of avast is 4.8.1335 so your copy was way out of date, so I don't know if that also means your virus signatures are also way out of date (latest VPS 090331-0) do you now have both at that version number ?
Where is the gphone.exe file located ?
You should check the gphone.exe at VirusTotal, Send a sample to avast if multiple detections at VT and Fix in HJT (see below)
####
Check the suspect file/s at:
VirusTotal - Multi engine on-line virus scanner and report the findings here in the topic, the URL in the Address bar of the VT results page.
Send the sample to
virus@avast.com zipped and password protected with the password in email body, a reference to this topic (give URL) and undetected malware in the subject.
