He/she never said "biggest". But an increase in corporate penetration would increase the value of OS X as a malware target, and that is what drives malware.
I stand corrected.
But an increase in corporate penetration would increase the value of OS X as a malware target, and that is what drives malware.
Are that many corporate LAN/WAN really run so badly that people can run botnets out of them on a regular basis? If that's the case, it's disappointing. If it's not, then I'd be a bit shocked at the prevalence of illegal corporate espionage.