What is the infected file name, where was it found e.g. (C:\windows\system32\infected-file-name.xxx) ?
Check the avast! Log Viewer (right click the avast 'a' icon), Warning section, this contains information on all avast detections.
The malware names often don't prove to helpful even if you do a google search for the name as there is no standardisation or naming convention. However, this -gen suffix usually relates to a generic signature that is trying to catch a type of malware. Unfortunately spyware can be a number of things,
http://en.wikipedia.org/wiki/Spyware, so this signature may be not be looking for specific but general actions, so it isn't easy to define what the spyware might be.
As clear as mud and this is often why a search for the infected file name may also return more detailed information.