My computer infected with this " Win32:Small-CCO " Trojan

File Name : C:\WINDOWS\Temp\_avast4_\unp19197489.tmp\[NsPack]
Malware Name : Win32:Small-CCO [Trj]
Malware Type : Trojan Horse
VPS version : 0654-1, 12/07/2006

What does this trojan can do to my PC ??
Anyway to remove or cure ?
I use Avast Antivirus to detect but it seem that i was unable to perform any action on it.

Normal AV should be able to remove them. try free AVG.

Here is the info,
A Trojan Downloader is a program typically installed through an exploit or some other deceptive means and that facilitates the download and installation of other malware and unwanted software onto a victim's PC. A Trojan Downloader may download adware, spyware or other malware from multiple servers or sources on the internet.

To make sure ur pc is clean from all the threat, use this to scan ur pc
http://housecall.trendmicro.com/