A new piece of malware for Mac OS X systems may be a danger to anyone who’s installed the Mac security product MacKeeper.
Mac users who’ve installed the controversial security and cleanup tool MacKeeper are being targeted by malware that uses the product’s security alerts to dupe users into installing data stealing software.
Most Mac owners will be familiar with the name MacKeeper. It’s original developer, Ukraine-based ZeoBit, recently settled over a $5 million US class-action suit alleging it misleadingly alerted users to security threats to convince them to upgrade from the free version to the $39.95 premium version.
The company’s new owner, German firm Kromtech, is also one of the largest buyers of online ads that targets systems running Mac OS X.
Adding to the company’s awkward relationship with Mac users, researcher Braden Thomas last month found a critical vulnerability in MacKeeper’s URL handler that could allow remote attackers to take over a machine if the user visited an website in the Safari browser.
That flaw is now being exploited by malware, according to Sergei Shevchenko, a cyber research specialist with BAE Systems Applied Intelligence.
A victim would have to receive a phishing email that contains a malicious URL to exploit the flaw.
“Once clicked, the users running MacKeeper will be presented with a dialog [box] that suggests they are infected with malware, prompting them for a password to remove this. The actual reason is so that the malware could be executed with the admin rights,” said Shevchenko.
This mirrors the functionality described in the original exploit: “If users have already been asked by MacKeeper for their password during the normal operation of the program, the rogue command will execute automatically. If not, the program will prompt them for their password, but the text on the dialog window can also be altered by the exploit, SecureMac reported at the time.
The malware goes beyond altering the dialogue window and installs a backdoor that gives the attacker remote access to the target computer, allowing them to extract files from the computer and install new files to the computer. The backdoor also collects system data, such as processes, the operating system name and version, the user name and the availability of VPN connections.
Questions remain over exactly how the malware authors would go about converting their software into installations and from there into revenue.
Mac OS X computers typically make up less than 10 percent share of the worldwide PC shipments and, according to Gartner, total desktop shipments totalled nearly 600 million last year.
Kromtech recently claimed that 20 million Mac users had installed MacKeeper, meaning it has a very small but not insignificant portion of Apple’s total desktop user base.
Shevchenko suggests the attackers might be “spraying” all Mac users with phishing emails to uncover vulnerable MacKeeper users.
The numbers would likely be small. However, another possible lure for the people behind the malware was information produced during the class-action against ZeoBit that showed that over 500,000 people had bought MacKeeper in the US — suggesting revenue of $26 million. Just two percent of this could be worthwhile, depending on how the prize was split up.
This article is brought to you by Enex TestLab, content directors for CSO Australia.