For several days Safari has been closing itself, opening itself and refusing to be closed some of the time. I'm afraid I can't remember exactly how, but I became aware of the suspicious sounding term "smart web search" just now and tried to google it, but (a) I couldn't pursue my search because of Safari closing down and (b) the first hits I got suggested that we were dealing with a virus (which I had begun to suspect) and talked about downloading ways to combat it which I was suspicious of as well.
[I am in Safari as I write this and seem to be ok at the moment – don't know why.]
I had a problem with there password manager LastPass recently and their Support directed me in this way:
"Can you please record your screen while reproducing the issue? You may use any of these screen recording tools: