How does one know if Flash is legitimate?

Question

This is mainly a paranoid question, but how do I know if a Flash installer is legitimate?
When I opened Safari today, I got prompted to update Flash. However, the window prompting the Flash update could have been launched from some open browser tab in Safari or another browser, couldn't it? So when I look at the window that prompts me to upgrade, what could I use as a sign to tell that this is a valid legitimate request to update?
As I am paranoid, I cancelled the update process and went to adobe.com and downloaded the update from there. In that way I at least know the origin of the file. However, surely that should not be necessary. Surely there is a way to recognise a legitimate update prompt?

Answer 1

Only EVER download Flash Player from Adobe's own website.
Two bugs, one affecting Apple's Mac platform and another attacking Microsoft's Windows, exploit certain Flash player vulnerabilities to install malware onto users' systems, reports ArsTechnica. While users of other operating systems like Linux have yet to report attacks, Adobe's advisory notes the exploit affects all platforms.
Designated as CVE-2013-0634, the first vulnerability targets the Safari and Firefox Web browsers running on OS X, and is also being used as a trojan to deploy Microsoft Word documents containing malware. For Mac users, the flaw affects Adobe Flash Player version 11.5.502.146 or earlier.
The Adobe Flash patch can be found on the company's website, and users can visit this page to check if their software is the most curent 11.5.502.149 version.