Green Granite: I wish I knew. Are these trojans classed as malware, thus virus protectors are not interested or are the freebies such as Avast and AVG not as good as the paid for stuff? To be fair, when I used to use AVG I did get the occasional popup declaring that AVG had blocked a virus. However, it let the trojan through which subsequently blocked all my malware detectors and AVG itself from updating itself. Thus I switched to Avast, however it may well be that this was a very new trojan which got in and protected itself in this way before the virus/malware detectors could update themselves. This (please excuse the plug again Saab) is why I like Malwarebytes. Most anti malware software needs to update itself with the latest signatures from its website as soon as it is installed. Malwarebytes doesn't as the download you obtain is fully up to date.
P.P.