A quick check of the address bar reveals that this isn’t Adobe’s website and what it’s trying to install is not Adobe Flash Player. It’s a fake version designed to trick unwary surfers into installing malware on your computer.
It’s a pretty good copy of the original, so you could easily be fooled if you clicked without thinking. As a comparison, the correct page should look something like this:
Fortunately I spotted the address at the top of the window (plus I know that Flash Player is built into Google Chrome anyway) but even if I hadn’t, my Antivirus program, ESET, detected the potential threat and offered to clean it for me.
It looks like this particular site has now been taken down, but it’s highly likely there are plenty more copies waiting to catch you out.
This just goes to show that no matter how careful you are, it’s still well worth having decent Antivirus software.