Recently, I upgraded Spyware Doctor from version 5 to 6. It was working fine until this morning when I started my computer. The resident shield in AVG 8 detected Trojan horse BackDoor.Hupigon4.ZSN.
I did an online search but did not find anything. It might be a false positive. Also, I found the computer to be slow in starting up. In the end, I uninstalled Spyware Doctor 6.