Why does it say this download is a virus?

Thanks for letting us know.  I've opened a bug to our web team to get this working appropriately.

In terms of your virus scanner, many AV products will flag product versions with known vulnerabilities.  You always want to be running the latest version of Flash Player, as attackers can look at the differences between binaries and reverse-engineer changes.  When we make proactive security fixes, it's possible for a skilled adversary to reverse engineer them and target unpatched clients. 

The archives exist primarily to facilitate compatibility testing, and that concept in an of itself is a throwback to the days before Flash Player had an auto-updater mechanism.  In the early 2000s, it was pretty normal to see the user population take 6-12 months to achieve critical mass on a particular product version.  With the addition of automatic updates, we see the same penetration within 48 hours of a release.

It used to be pretty common for a client to specify "We want our game to work on Flash Player X and higher", but because the majority of users are on the current version, and there aren't really big deltas in terms of backward compatibility (3D graphics support and hardware acceleration are well-established and mature, etc.), there's not really a compelling reason to worry about that kind of backward compatibility at this point.  We mostly provide those downloads because there's a historical precedent.

Unless there's a spectacularly compelling reason (e.g. you're maintaining a kiosk in a museum that will never access the open web, and for some reason, your content won't play on a current versions of Flash Player), you shouldn't need to grab archived builds.  You definitely don't want to be browsing the open web with them.

Hi,

I tried downloading Flash Player 6 and faced no issues while downloading the same. Which country/geo are you located in?

Thanks!