Last week, over 600,000 Macs were infected with a new trojan called the Flashback trojan, and even if you've updated your software, you could still be infected. Here's an app that will check your computer for the trojan, and how to remove it if you find you're infected.
Nearly 2 per cent of owners who checked their computers using Russian antivirus web tool Dr Web found that their computers were infected, so if you haven't checked yet, now's the time. Previously, you had to enter a few terminal commands to search for the trojan on your system, but now there's a much simpler way: just download the FlashbackChecker app and run it on your system. It will automatically search your computer for signs of the Flashback trojan and let you know if you're safe. If you're rather tech savvy, you've probably already checked your computer using the aforementioned commands -- but this is a great app to send to less tech-savvy family members that might not know if they've been infected.
Note that FlashbackChecker can't actually remove the trojan, it can only detect it. So, if you or a family member does find it on their machine, you'll have to go back and run those original terminal commands to determine exactly what you need to remove. Check out F-Secure's instructions for removing the trojan for more info, as the commands are a bit more involved. And, as always, make sure you run Software Update from the Apple menu to make sure you can't get this trojan in the future.