I've paid "McAfee SecurityCenter" for the next 2 years.
Two times I need to activate "Spybot - Search & Destroy" to find & delete "Win32.Downloader.gen".
I don't know what it was but it has "disturbed" my browser Firefox.
Can McAfee automatically find such "culprit" and remove it after asking my permission?
What software do I need?
It isn't necessarily an infection according to my online searches. Rather it is an unknown and there is an excellent guide here: http://malwaretips.com/blogs/win32-downloader-gen-trojan/
We don't recommend Spybot as it can react negatively with McAfee software. For tools that are recommended see the last link in my signature below, especially under "Free 3rd Party Tools".
If and when McAfee finds unknowns that it suspects it will quarantine them as "Artemis...." type detections and will automatically submit them for analysis.
This is a Spybot-only detection and is likely to be a false positive. None of the other AV vendors detect a problem with whatever file Spybot is objecting to.
From this Microsoft thread -
If TDSSKiller, Malwarebytes Free, the Eset Online Scanner and Hitman Pro could not identify, locate and remove this malware I would probably be suspicious about the identification of same by Spybot.