I downloaded and ran Symantec’s Netsky removal tool and found that Netsky had left droppings all over my system. After about 30 minutes, it found and deleted a few hundred files, almost all of which were creatively named EXE files waiting to re-infect my system should I accidentally click on them. (Well, technically, the McAfee on-access scanner deleted the file just as the removal tool “touched” them. McAfee’s tool found hundreds of droppings, but it missed three .tmp files that Symantec’s tool actually deleted.)
Now my computer is returned to its normally demented state: 
.