Trojan.downloader.agent.Al

I'm running win2000, IE6.0.28 & Firefox.8 and avg6 virus software ( latest signatures), Zone alarm pro, Spybot S&D.
On my automated daily scan on May 18th AVG detected Trojan.downloader.agent.Al in c:\winnt\system32\Winhost32.exe. It also found downloader.1stbar.3.BC in inst_install.exe and was unable to repair/heal it - I manually deleted it and it has not returned.
In over 2 years of use this is the first time anything has gotten past AVG.
AVG could not repair the Winhost32 file and could not quarantine it.
I manually deleted the file.
About 3/4 hours later AVG popped up and reported the trojan again.
I repeated the scan and again manually deleted it as AVG could not.
This has now been going on for 4 days.
Attached is my Hijackthis log.
Any ideas on how to remove this pesky @&^!$*?

 

Hi Mike Coleman,

Welcome to Wilders.

I will move your thread over to the adware/spyware/hijack cleaning forum where it will get the appropriate attention. Someone will review your log and post instructions for you on what needs to be fixed.

Regards,

snap