Security researchers at ESET have discovered a dangerous new Mac backdoor program which allows attackers to gain full control of a Mac computer. Mac malware may be relatively rare compared to malware used to infect PCs, but the latest discovery clearly demonstrates that Mac users are not immune to cyberattacks. The new OS X malware has been dubbed OSX/Keydnap by ESET. This is the second Mac backdoor program to be discovered in the past few days.

OSX/Keydnap is distributed as a zip file containing an executable disguised as a text file or image. If the file is opened, it will download the icloudsyncd backdoor which communicates with the attackers C&C via the Tor network. The malware will attempt to gain root access by asking for the users credentials in a pop up box when an application is run. If root access is gained, the malware will run each time the device is booted.

The malware is capable of downloading files and scripts, running shell commands, and sending output to the attackers. The malware is also able to update itself and also exfiltrates OS X keychain data.

Second Mac Backdoor Discovery in Days

The news of OSX/Keydnap comes just a matter of hours after security researchers at Bitdefender announced the discovery of another Mac backdoor program called Eleanor. Hackers had managed to get the Backdoor.MAC.Eleanor malware onto MacUpdate. It is hidden in a free downloadable app called EasyDoc Converter.

EasyDoc Converter allowed Mac users to quickly and easily convert files into Word document format; however, rather than doing this, the app installed a backdoor in users’ systems. Infections with Eleanor will be limited as the app does not come with certificate issued to an Apple Developer ID. This will make it harder for many individuals to open the app.

However, if users do install the app, a shell script will be run that will check to see if the malware has already been installed and whether Little Snitch is present on the device. If the Little Snitch network monitor is not installed, the malware will install three LaunchAgents together with a hidden folder full of executable files used by the malware. The files are named to make them appear as if they are dropbox files.

The LaunchAgents open a Tor hidden service through which attackers can communicate with a web service component, which is also initiated by the LaunchAgents. A Pastebin agent is also launched which is used to upload the Mac’s Tor address to Pastebin where it can be accessed by the attackers. The Mac backdoor program can reportedly be used for remote code execution, to access the file system, and also to gain access to the webcam.