A newly observed variant of the macOS-targeting Proton malware is spreading through a blog spoofing that of legitimate security company Symantec.
The actor behind this threat created symantecblog[dot]com, a good imitation of the real Symantec blog, and even mirrored content from the original. On this blog, a post about a new version of CoinThief, a piece of malware from 2014, promotes an application called “Symantec Malware Detector,” while in fact distributing OSX.Proton instead.
The domain’s registration information appears to be legitimate, with the same name and address as those used by Symantec, but the email address shows that something is off. Furthermore, the certificate used for the site is a legitimate SSL certificate issued by Comodo and not by Symantec’s own certificate authority.
Links to the fake blog have been spreading on Twitter via both fake and legitimate accounts, Malwarebytes reports. It is possible that the actor behind this campaign used stolen passwords to access legitimate accounts and promote their malicious post. However, it is also possible that people were tricked into promoting the link.
When first run, the Symantec Malware Detector application displays a very simple window, using the Symantec logo, claiming to require authorization to perform a system check. Should the potential victim close the window at this point, the malware won’t be installed, the researchers say.
Should the user agree to run the check, the admin password is requested, a step that results in the malware stealing the password. Next, the app displays a progress bar claiming to be scanning the computer, but Proton is installed in the background.
The Symantec Malware Detector application is nothing more than a malware dropper, and all users who have downloaded it are advised to delete it and attempt to disinfect their systems.
The malware immediately starts gathering user information, such as the admin password and other personally-identifying information (PII), and saves all data to a hidden file. Keychain files, browser auto-fill data, 1Password vaults, and GPG passwords are also harvested.
The Proton executable is dropped in the .random directory and is kept running by the com.apple.xpcd.plist launch agent. The stolen data is stored in the .cachedir folder.
“Fortunately, Apple is aware of this malware and has revoked the certificate used to sign the malware. This will prevent future infections by the Symantec Malware Detector. Revoking the certificate will not, by itself, do anything to protect a machine that is already infected,” the security researchers explain.
Proton has been designed to steal login credentials and affected users are advised to take emergency actions post-infection. They should consider all of their online passwords as compromised and change all of them, while also setting up a different password for each site and storing all of them in a password manager. The master password should not be stored in the keychain or anywhere else on the computer. Enabling two-factor authentication should also minimize the impact.
This incident, the researchers note, shows the danger of fake news being used to spread malware. Due to the increased prevalence of adware for macOS, many users are looking to download malware removal tools, and cybercriminals are attempting to take advantage of that.
“Proton has been circulating for quite some time after its initial appearance in March. It has previously been distributed via a compromise of the Handbrake application and a similar compromise of a couple Eltima Software applications. It is highly likely that Proton will continue to circulate, and similar incidents will continue to occur,” Malwarebytes concludes.
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