There have been a few pagefile.sys detections recently on the windows avast 4 Home/Pro forum, I'm not sure how reliable this is as there is no way to check (e.g. it can't say what is infected as it treats it as a single file) since the size of the pagefile.sys it will probably be too big to send to the chest. I have excluded mine in the standard shield exclusions, ?:\pagefile.sys so it covers pagefile.sys files on other drives.
Note:
The above exclusion path would need to be modified.