Antivirus vendor Kaspersky Lab has launched a free removal tool for the Flashback Mac OS X malware and a website where users can check whether their computers are infected with it.
Flashback is the most widespread malware on the Mac OS X platform to date. Two antivirus companies, Doctor Web and Kaspersky Lab, independently confirmed on Wednesday and Friday, respectively, that well over 600,000 Mac computers have been infected with the latest variant of the Flashback Trojan horse.
Flashback first appeared in September 2011 and was originally distributed as a fake Flash Player installer. However, the number of infections drastically increased in March because the malware started infecting computers through Web-based attacks that exploited an unpatched Java vulnerability.
Antivirus vendor F-Secure was the first to publish instructions on how to check whether a Mac OS X system is infected with the latest Flashback variant and how to manually remove it.
However, F-Secure's instructions required users to type complicated commands in a Mac OS X terminal window and interpret the replies, which made them somewhat unsuitable for non-technical persons used to a graphical user interface.
In order to make it easier for average users to check whether their computers are infected, Kaspersky Lab launched a website on Monday where people can input their systems' unique hardware identifiers (UUIDs) to see if they are among the almost 700,000 Macs known to be infected with Flashback so far.
Kaspersky also released a stand-alone removal tool for the Flashback malware, which Mac owners can download and use for free. However, it's probably a good idea to install a full-featured antivirus program after running this tool in order to prevent future infections.
In addition, Kaspersky's director of global research and analysis, Costin Raiu, made several Mac OS X security recommendations in a blog post on Monday. These included setting up a non-administrator account for everyday use, switching to Google Chrome as primary browser because of its sandboxed Flash Player plug-in and silent automatic updates, disabling the Java and stand-alone Flash Player plug-ins from other browsers, installing all software updates distributed by Apple, upgrading Adobe Reader to version 10, using a separate keychain for passwords that can unlock very sensitive accounts and disabling the IPv6, AirPort or Bluetooth services when they're not needed and enabling full disk encryption.