I have not changed all my passwords perhaps I should. I have changed quite a few. I am fairly sure it came via yahoo because 'yahoo' appeared in quite a number of files that were infected.
I am still now sure that I understand the difference between a virus, a Trojan and malware. Seems the protection software simply say that you have the wrong type, if they do not detect the problem!!! As for not covering windows 10 that is outrageous. I did not ask for it, I do not want it, I still hate it. Basically anyone with windows 10 would appear to have a security risk if that is the case.
It is revealing that Mcafee say they have got rid of 9 viruses of which 2 were malware and 2 were Trojans so not clear why they said this Trojan was not covered. Basically I do not think they are up to date enough.
BT said I would have to take the computer to an engineer to get it fixed, so still cannot quite believe in the end it was relatively easy.