I have seen many popup updates for FP this year however when I examine the link it is clearly not linked to Adobe, and I also read the bottom of this latest update saying they are not affiliated with Adobe and is a 3rd party software needed to run video's from other sites. if this is or is not legit it needs to be know as what exploits have plagued FP in the past some are leery to install these popups as I am. below is a snapshot of the popup and when I went to "contact" to see what came up it shows it is a CRITICAL UPDATE that must be installed. Very Suspicious ! , note the link easyjavaupdate.be , after clicking on "Contact" the "Warning" pop up appeared.
You were right to question this. The only legitimate Flash Player updates come from either adobe.com or macromedia.com. Any other site, or an update notification stating they are not affiliated with Adobe, is absolutely not a legitimate site, or update notification, for obtaining Flash Player. If you keep on getting notifications such as this, I'm guessing your system is infected with some sort of malware/adware. I recommend scanning your system for these using something such as MalwareBytes or similar.
Thank you for posting this screenshot. I'll forward it to the appropriate folks who handle malicious sites purporting to be distributing Flash Player.