Seattle, WA, JUNE, 2020
Intego has discovered new Mac malware in the wild, actively spreading through malicious results in Google searches.
The new malware tricks victims into bypassing Apple’s built-in macOS security protections, and it uses sneaky tactics in an effort to evade antivirus detection.
As of Friday, the new malware installer and its payload had a 0/60 detection rate among all antivirus engines on VirusTotal. Intego VirusBarrier is the first anti-malware solution that is known to detect and remove this malware.
Intego identifies the new malware as unique new variants of OSX/Shlayer (the original variant of which was first discovered by Intego in 2018) and OSX/Bundlore (with similarities to past versions of OSX/MacOffers and Mughthesec/BundleMeUp/Adload).
What does the new malware do? How is it unique?
As is commonly seen in Mac malware, this newly updated Shlayer malware is delivered as a Trojan horse application on a .dmg disk image, masquerading as an Adobe Flash Player installer.
After the deceptive Flash Player installer is downloaded and opened on a victim’s Mac, the disk image will mount and display instructions on how to install it. The instructions tell users to first “right-click” on flash installer and select Open, and then to click Open in the resulting dialog box.
If a user follows the instructions, the “installer app” launches. While the installer has a Flash Player icon and looks like a normal Mac app, it’s actually a bash shell script that will briefly open and run itself in the Terminal app.
As the script runs, it extracts a self-embedded, password-protected .zip archive file, which contains a traditional (though malicious) Mac .app bundle. After installing the Mac app into a hidden temporary folder, it launches the Mac app and quits the Terminal. All this takes place within a split second.
Once the Mac app launches, it downloads a legitimate, Adobe-signed Flash Player installer, so that it can appear to be genuine—but the hidden Mac app is designed to also have the capability to download any other Mac malware or adware package, at the discretion of those controlling the servers to which the hidden Mac app phones home.
The developers’ decision to hide the Mac .app within a password-protected .zip file, and to hide that within a bash shell script, is a novel idea—and it is also extremely clear evidence that the developers are trying to evade detection by antivirus software.
How can the malware be removed?
Intego VirusBarrier X9, included with Intego’s Mac Premium Bundle X9, can detect and eliminate this malware. (Customers running VirusBarrier X8, X7, or X6 on older versions of Mac OS X are also protected.)
Very few other third-party antivirus solutions are known to detect it, as of when this article was last updated.
Intego offers an award-winning line of products providing Mac security and enhancing Mac performance. Intego has been designing software to protect and optimize Apple products for over 17 years. No other company has been focused on Mac security and performance as long as Intego. Intego creates products for a full range of Mac and iOS devices, such as iPhones and iPads. Its depth of experience allows the company to create software that not only works well, but is elegant and intuitive. Much like a Mac.