Your penultimate paragraph omits to state the fact that computers using Apple or Linux operating systems were not affected.

McAfee's update was for those using Microsoft Operating System software. This brings to mind that the commonly used statement "computer virus" should be replaced by "Microsoft Operating System virus" so that readers will be made aware that there are methods of running computers that will be more integrity effective than reliance on virus protection updates.

I quote an extract form a knowledgeable source written just a few days ago:
“The London Stock Exchange switched its system over from Windows to Linux a year or two ago following a similar attack. The New York Stock Exchange has been run on Linux for several years, for the same reason. The bad guys are increasingly targeting large corporation with increasingly sophisticated attacks. These attacks cost them millions of dollars, and place their proprietary software and data at risk. As these attacks continue to increase exponentially in number and severity, we will see more and more of the world's largest companies jumping off the Windows ship, in self-defense. We may not have reached the tipping point [change to Linux] yet, but the pace is accelerating, and the day will come, sooner rather than later.”

The attack referred to was that suffered by the Waikato Health Board.

Another source made the comment:
“I was at a term store down across from the docks and the owner showed me a flimsey from a magazine and the thrust was that the number of REAL bad stuff, virii, trojans you name it, not just "stuff" has increased by a factor of like FOUR in the last year alone,
The thing is that most of these are slightly altered clones of a prototype, but problem is that it doesn't matter if it is a modified clone or something totally new, the thing still has to be dealt with, which takes time, person power and money.”