Back in the day, fake AV mostly consisted of some poorly contrived browser pop-up in an attempt to alarm the target user with messages of doom and gloom -- with the only solution, of course, being to download a copy of the advertised [fake] antivirus solution. Although the pop-up warning would typically pretend to do a scan of your system -- fully equipped with a fake scan progress bar and results presenting a grim inventory of the threats purportedly on your system -- the ruse would end after installing the advertised software.
Some variants would install a little system tray icon, occasionally advertising that the fake antivirus software had protected you from some fake threat. That's about as complex as it got. Things have since evolved.
Earlier this month, I was stuck by a new piece of malware that came across my desk. As the name suggests, the malware (entitled MacDefender) not only coaxes users through many of the aforementioned tricks, but once installed maintains its cover by installing what appears to be a fully featured OSX antivirus product. As you would expect from a modern AV product, MAC Defender features a configurations screen, statistics such as the signature count, signature revision date, and the total number of viruses it has "found" for you. It goes one step further -- in order to remove the nonexisting infections that MAC Defender pretends to find, you must first register the software through the official site (albeit no longer operating) for a cool $59.95 per year. In case you aren’t convinced, MAC Defender will cause your default Web browser to open a series of websites only fit for the eyes of the most hardened of Internet aficionados, in addition to continuing to report infections through its notification window.
While it is certainly true to say this isn’t the most advanced piece of malware we are likely to see this year, it’s an interesting progression for this threat class and indicates that actors looking to monetize from malware infections are continuing to invest in developing increasingly convincing fake software in order to maintain their cover. After all, MAC Defender and scareware like it are a generation ahead of their predecessors, which were content with a few browser pop-ups and an off-the-shelf remote access tool (RAT).
It also further evidences the increasing number of attacks against users of Mac OSX, an operating system that many have felt a degree of security in using, if only out of naivety for the possibility of future threats. Zero-day is also not getting any cheaper, so while threat actors continue to see a return on investment from this type of effort, I believe that we will continue to see more and more of this sort of thing hit the threatscape.
The solution? First and foremost, user education. Technologically speaking, while many will tell you (including me) that it can often be easily defeated, application whitelisting is a great first step for combating this type of threat. A number of solutions exist that are community-sourced, meaning that the more users who use and are not complaining about a given piece of software, the higher the trust is given to the code once installed. This still relies on some common sense in not clicking the big, red “continue to install even though it’s probably badness” button. However, it’s a step in the right direction for less sophisticated users and puts the threat factor back onto their back foot, having to come up with new, more expensive ways to make their money due to a reduced return on investment.
Tom Parker is director of security consulting services at Securicon.