Historical tech post: Flash updates (Mon, 17 Nov 2008)

I wondered how Flash knew to install updates after a login. After all, it is a browser plugin. The plugin checks for updates if allowed, and that is a user settable option. When visiting a Flash-enabled site, and when the update check finds that Flash is out of date, the plugin installs a RunOnce registry key. This is done silently, and most of us do not check for such a key every few minutes. The next time the user logs in, possibly days later, and even though the browser plugin is not yet running, the registry key starts the update process. The user might then wonder what started the update, but by that time, the RunOnce key has already deleted itself. Sneaky, but safe.