Adobe, along with partners like Microsoft and Google, are continuously investing in both hardening Flash Player against attack, and in identifying and mitigating emerging threats identified through operational intelligence and academic research. We have a dedicated security incident response team, and in the event that security issues are discovered in the wild, we move quickly to identify and correct the issue, and push a patch out to the world.
To ensure downloads are authentic, you could always download them direct from Adobe's website, and we highly recommend that you enable automatic updates, to ensure that the latest patches are always applied.