Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
OS X reinstallation
There’s been a lot of talks and comments about last week’s Trojan malware attack and the ways to solve the problem.If you figured out that the best decision for you would be to wipe your system and start over –- here is how you do it without erasing your data
Sync and back up
First thing you need to do is make sure your system is adequately synced to your Cloud-based services(iCloud,Google,Yahoo,etc.)in order to make sure all your calendars and contacts are saved.Another good idea is to go to Address Book, iCal, and other programs that you use regularly and export calendars,contacts and other data to a flash drive or other separate storage medium.These actions will let you restore some of those items without relying on sync services to manage them for you.Also,make sure your system is backed up.Use a cloning tool or Time Machine to back up your files,or copy all the folders from your home directory to an external hard drive.Do that for every active account on the system by logging into each and executing these actions.
Deauthorize or unregister applications
Some applications,like iTunes etc. have authorization and registration features for viewing and managing content,so be sure to deauthorize these features before you proceed to erasing your system as you might run into problems when configuring programs again.Some apps only allow a certain number of computers to be authorized to a specific account,that’s why,in order to avoid further issues with authorization,make sure you sign out all of your apps.
Format the drive
Reboot the system to the OS X installation DVD for OS X 10.6 or earlier (hold the C key at startup with the DVD in the optical drive), or reboot with the Command-R keys held for OS X 10.7. When the OS X installer loads, select your language and then open Disk Utility (available in the Utilities menu if it’-s not presented in a Tools window).
In Disk Utility, pick your boot volume and then use the Erase tab to format it to “-Mac OS X Extended (journaled).”- This process should be fairly quick, and when done should leave you with a blank hard disk.
Reinstall OS X
Quit Disk Utility and then open the OS X installer. Do not choose any option to restore from backup. Follow the onscreen instructions to select your newly formatted hard drive and reinstall OS X, and then wait for the installation to complete.
Create a new account
After OS X is installed it’ll ask you whether you’d like to copy data from a backup or from another computer.Instead of doing this create a fresh user account for yourself(you can use the same account name and other info.)
Update the system
Next step is the system update.Go to Software Update (in the Apple menu) and update your system to the latest version.Execute this operations several times until no more updates are available.
Often Java is not needed to run applications in OS X,so,unless you have specific need for it –- turn it off.The latest Trojan Flashback malware attacks were directed onto Java vulnerabilities.Even if you do need Java –- it is better to start with it disabled.
Restore your data from backup
Next thing you want to do is to copy your data back to your system from your backups.Using Apple’s Migration Assistant tool might not be a good idea since it will restore files and application that may have been affected by the malware.That’s why,instead of doing that copy your files from your Documents,Movies,Music and other home directory to their respective locations within your user account.
Now you can set up iCloud ot other sync services in the system preferences,launch Address Book,Mail,iCal and other programs you use that you need to configure with your accounts.In case you’re missing your contacts and calendars,you can re-import them from the manual backups you previously created.
The final step after restoring your accounts is to reinstall the apps you use.Since your previous apps were backed up before you started this procedure,avoid restoring them or opening because one of ways the Flashback malware affects your computer is directly via those programs.
Instead, use the backup as a reference for which applications you previously had and reinstall them from their installation discs, the Mac App Store, or other means by which you originally obtained them.
After you installed your applications,make sure you to fully update them and then configure them according to your preferences.At this point your system should be back to a usable state and you should be able to work with it just the way you did before reinstalling.If you find you’re missing something,like fonts,sounds or other files that you apps need –- you can access them from the global library folder from the backup.
The final thing to do is protect your Mac from further infection.While disabling Java is one step,another very important one is installing a good firewall that would scan download folders and scan the whole system either once a week or once a month.