Looking further, I've found that a folder '$Windows.~BT' has appeared on my C-drive. It's some 4.07 Gb in size and includes 15,595 files in 3,380 folders, all of which concern Windows 10.....
Yes, that's apparently the advanced symptom of this un-requested malware.
From what I've read, there were eight 'upgrades' to W7 & W8 which facilitated the development reported above. The original article lists the upgrades, and gives details for a good old fashioned DOS based batch file to un-install them.
There are also details for a registry addition to steer clear of this development, but it may be too late for that in a lot of instances.
I've done both of these mods to my currently available Win7 machine, and the issue
seems to have gone - for the present.
However, I'm most reluctant to share these fixes at this stage, primarily because of possible repercussions from people on this board who have intimidated the more timid users into a cautious reluctance to share such radical information. I also don't want to be suggesting changes to other people's computers which need a bit more time to be proven as rock solid safe.
If the information in the original SIG posting I read this morning is true, then there's no way in the world that I would touch Windows 10 - ever! The posting identifies some quite frightening potential issues, which most users will be blissfully unaware of - at least in the early stages.
It looks very much like W7 - and perhaps W8 - will be the last versions of Windows for this particular user.
BTW, the source of this information would appear to be highly reliable, and what it reports is what I have discovered on my own W7 machine.
I'm sorry but that's about as much of the reported information as I want to share at this stage - for reasons I've already stated.
FOR