According to Trend Micro’s Ivan Macalintal, the backdoor may infect users’ machine when they access remote sites hosting the malware. Also, it may appear as a genuine application, inviting users to download and execute it.

Once the user decides to launch the bogus app, he is asked to choose an application and a port above 1024. Then the backdoor creates the file /tmp/ and copies this file in the location ~/Library/LaunchAgents. After it has been loaded, the malware deletes the file so the backdoor would be able to execute everytime the system starts up.

The researcher adds "that these malware routines compromise security, as remote malicious users may gain access to an affected system. OSX_LAMZEV.A also has autostart features, so turning one’s infected Mac on automatically runs the backdoor."

So just be careful what apps are you willing to run on your system. It may be the last one on a clean computer.