Thank you for reporting this. As per the URL this is NOT an official Flash Player installer. Please do not download the file. Please private message me the entire URL and I will forward it to our security/fraud team.
I recommend you run an entire system scan for viruses, malware, adware, etc.
Do you have the page URL, not just download URL?
Definitely a fake, as denoted by the non-adobe URL. I'll forward this to our fraud team for follow-up. In the future, please send it directly to firstname.lastname@example.org.
Please note that fake alerts can be caused by Ads that have been infected with malicious code (so-called Malvertising) or even by malware/viruses itself. You help help protect your system by running up-to-date anti-virus, malware, etc software, performing regular virus/malware/etc scans, and blocking ads (if feasible, as some sites now require ads to be unblocked in order to view content).
I'm going to lock this discussion topic - it's quite old with quite a few different people on it. Every time there's a new post, everyone receives an email notification.
For those of you that are getting these fake Flash Player update notifications, please take a screenshot of the entire page, including the address field with the full URL. Depending on the browser, you may need to click in the address field to display the entire URL. Send the URL and the screenshot to email@example.com. To take a screenshot, see https://forums.adobe.com/docs/DOC-7043#jive_content_id_How_do_I_attach_a_screenshot