How can I find out more info on this trojan. AVAST scanned my C drive and found three files infected by this trojan.

Welcome shinynavigator

Seems to be a trojan identified by avast and added to their database list here. Different anti-virus vendors use different naming criteria but I cannot find a cross reference on this one.

However, there a numerous variants of Win32.Small as shown by a simple Google search here

If your running Win XP/2000, download and scan with Ewido Anti-Spyware v4.0 in "SAFE MODE".
Print out the Ewido Install and Scan Instructions.

Then perform these online Virus scans:
[Watch the Address bar in IE. You may receive alerts that "This site might require the following ActiveX control...Click here to install...". Click on that alert and then Click Install ActiveX component.]
Trend Micro Housecall Scan
Panda ActiveScan