Is the title of your post the information you got from the Avast file? Is this a worm? Can't tell from what you wrote.
Of the programs you ran, Avast, TrendMicro and a-squared
are anti-virus programs. They should have found it.
I would suggest a further search from BitDefender.com.
They will sometimes find things that none of the "big boys" can. It is a free scan. Whataya got to lose?
I run Xp Pro. SP 2.
A few days ago I received a virus detection warning via my anti virus program that a virus was detected.
I however noticed the next day that my system was loading every website slow. I used Spybot, Ewido,Lavasoft adaware, Xoftspy and Avast Home but all came up clean. Yet the system remains drunk slow. I further tried House call and a squared but to no avail.
A further check in avast warning folder showed that a trace of the captioned virus was detected but nothing was shown in the virus chest.
I also noticed that when I move from one page to the next that the requested page came up minimized necessitating that I maximise it.
From the syntoms I suspect that the system is infected. Despite my searches I have not been able find a how to.
I shall be grateful you your kind assistance.