I’m surprised I didn’t catch this earlier. Craig Schmugar at McAfee gets it in his blog post:
Having said all this, these points are not what make this threat significant. What sets this threat apart from other proof-of-concept Mac threats and low-scale attacks is the entity behind it. Puper (a.k.a. Zlob) is one of the most widely reported pieces of malware for Windows. McAfee VirusScan Online users reported more than 4 million detections during the past two years. Microsoft’s latest security threat report states Zlob was the most frequently disinfected piece of malware. Unlike earlier Windows malware, this Mac Trojan is authored by professionals who likely pull in thousands of dollars a month through click fraud, hijacked affiliate sales, and other illegal activity.