Whatever you do, stuff happens!
A good number of the posts in this thread seem to be relatively thoughtless (you may freely include this one, too, if you wish).
Malware (MW) is MW, and it's all bad stuff. The technical distinctions among them (virus, trojan, etc.) are likely to be useful to only a very small segment of the entire user population. My experience with the rest is divided: some are at lesser risk, because what they've heard and digested has prompted them to never, ever update, or even check a YES box, on a computer; others, at much more risk, will blithely do anything their computer prompts them to do, in whatever form. And my impression is that neither group is particularly amenable to a little technical educational help, and, whatever you tell them, stick to their guns, or, at least, to their practices. This isn't because most users are dopes, or senile. They're simply not interested enough to involve themselves in something they feel is so secondary and arcane (which almost all members of this forum, for instance, are interested in, for whatever reasons). So this haggling about the distinction among MW types and mechanisms is largely irrelevant to most "normal" people (unlike us).
MW creators (who use or sell their know-how to devious ends - not all do, you know) are bad people, but they're smart, and keep learning all the time. Whatever their various motivations, sport certainly ranks high. "Can I do this or that" and "Can I do it better?" is an important driver, not unlike pros, or even tyros, in other arenas, except they lack maturity, or the conscience and behaviour which usually comes with it. They will always be around, like chronic speeders.
Because of this, the sophistication of MW will get higher and higher, so that it will get harder and harder for most computer users (and here I include a good number of us, in this forum) to smell the danger, let alone combat it, whatever kind it is.
OS (and app, especially Anti-MW app) creators will never become blasé about the MW danger, whatever impression you might sometimes get from their press releases. Quite the contrary. Consequently, they're constantly on the alert to their possible or potential vulnerabilities, doing the best they can to make themselves bulletproof (knowing full well that absolutely bulletproof is impossible, even for a rock), and keep up with and study the attacks which will come, repair the damage, and build a better version as soon as they can.
All this is like the interplay of disease and medicine in the human body. There are bad diseases and less serious ones, there's good medicine and bad medicine, and there's good luck and bad luck, all of that in some combination all the time. But there are no guarantees of absolutly perfect health always. Never. Stuff happens, whatever care you take.
