OK, so we've trusted Apple's vaunted security protocols and installed their update. No tell us what the **** malware does. Please. Has my financial info been compromised? Passwords? Keychain? What????
See About the Flashback malware. (Note that my pages contain links to other pages that promote my services, and this should not be taken as an endorsement of my services by Apple.)
As to what it does, there's no real documentation on that. There are a few scattered reports here and there, like that it will redirect search results in your browser to malicious sites, but it was basically capable of anything. It injected code into your web browser at a minimum, and could have snooped on anything that you did with your browser. So you'd be wise to keep an eye on your finances, change any financial site passwords, cancel any credit cards the instant any suspicious charges appear, etc. You may want to pay for something like LifeLock to keep an eye on your credit rating and help you fix any problems that appear. That could be overkill, or it could save you from long-lasting financial consequences.