I do know that my iMac didn't "feel right" for about a month. It was losing ability to respond to mouse clicks and balking at closing some aps and at shutting down.
Since then no problems.
And yes, I did get stupid and allow a flash player update before the trouble started.
Off hand, I'd say I was zombiefied, but I'm not 100% certain.
Null, there WAS a version of the Trojan that installed with a bogus Flash update. It popped up on a website and required an Admin user name and password. It did not take you to the Adobe website for updating. Was that what you encountered? If so, it was not this particular Flashback Trojan; it was an earlier version that was pretty innocuous.
Was this install as long ago as August? That was Trojan Bash/QHost.WB... but since then your Mac should have recognized it and not allowed you to download it—unless you overrode the warning.
What OSX version are you running? You can check that by clicking on the Apple in the menu bar and selecting "About This Mac."
To avoid this happening again, go into your browsers' preferences and turn off JAVA. You can safely leave Javascript running... just JAVA needs to be off.