Ever since the discovery of the MACDefender malware last month there have been numerous articles, blog posts, and discussions on the topic. Read more about it in our newsletter on Mac Malware and Better Passwords.

One possible solution is this: Avast has just launched a new free antivirus software for Mac (still in beta testing). It automatically updates its virus definitions, and monitors the web and email as well as files on the computer.

Avast is a company that has been offering free antivirus software for the PC since the late 1980s. The company was founded by two Czech technologists. Their site says that each month their software detects over 1 billion pieces of malware.

To use Avast you also need to download and install a piece of software called Growl in order to get the notifications on any viruses it finds.

I installed the Avast Mac antivirus software and took it for a test drive. It’s extremely simple: The left-hand side of the window lets you look at an overview of your computer’s virus status, perform a scan of your computer/your home folder/any file, or read scan reports.

The software runs in the background while you’re working on other things. It did slow down my computer fairly noticeably while it was performing its scan. The good news is that I’m virus-free!