There is a dog forum I visit. Each time I visit it I get the Adobe update flash to download it. I don't, but does that mean that forum isn't safe? Also, I found this on my notebook. Is it supposed to be there? There are no strange applications when I check there.
That forum like uses Adobe Flash, assuming you have some version of Flash installed or are using Chrome, that version on the forum wants a newer one, thus the upgrade notice. Ignore the message, do not upgrade Flash. If you DO have Flash installed, uninstall it and use Chrome for sites that absolutely want to use Flash. Virtually all sties have totally abandoned Flash since Adobe themselves have stopped working on/supporting it.