New Mac Malware Combines Open-Source Backdoor and Crypto-Miner

A recently discovered piece of malware targeting Mac systems is a combination of two open-source programs, Malwarebytes security researchers warn. 

Detected as DarthMiner, the threat is distributed through an application called Adobe Zii, which supposedly helps in the piracy of various Adobe programs, but which in this case does nothing of the sort. In fact, the fake Adobe Zii software doesn’t even use the stolen Adobe Creative Cloud logo, but a generic Automator applet icon instead.

The fake application was designed to run a shell script that downloads and executes a Python script, and then downloads and runs an app named sample.app, which appears to be a version of Adobe Zii, most likely to hide the malicious activity. 

The obfuscated Python script looks for the presence of Little Snitch, a commonly-used outgoing firewall, and stops the infection process if the tool is found (although the firewall should have already blocked the script’s download attempts, Malwarebytes says).

Next, the script opens a connection to an EmPyre backend, a backdoor that can execute arbitrary commands on the infected Mac. The backdoor then downloads a script that fetches and installs the other components of the malware. A launch agent is also created to ensure persistence. 

In addition to the backdoor, the attack also results in the XMRig cryptominer being installed on the compromised Mac. A launch agent is created to keep the XMRig process running. 

Analysis of the script also revealed code to download and install a root certificate for the mitmproxy tool, which can intercept web traffic, including encrypted traffic. The code, however, has been commented out, meaning that it isn’t active in the observed malware. 

While the threat only appears to do little harm, as it only slows a machine down by running said crypto-miner, the backdoor could be used to send other arbitrary commands to infected Macs. 

“It’s impossible to know exactly what damage this malware might have done to infected systems. Just because we have only observed the mining behavior does not mean it hasn’t ever done other things,” Malwarebytes notes. 

Another issue that this attack brings to the spotlight, the security researchers point out, is the fact that software piracy could pose high risks to users. However, although programs that facilitate such illegal operations represent a great infection vector, many users still engage in such behavior. 

“Please, in the future, do yourself a favor and don’t pirate software. The costs can be far higher than purchasing the software you’re trying to get for free,” Malwarebytes concludes. 

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