I noticed this too; around 8:30PM yesterday 23rd October. PCMag reported it, and I verified its authenticity through Windows Update, installed it on both my machines, then reported it on my blog in a special article at http://kkomp.com/archives/2313.

It had a critical severity rating, and for Microsoft to go into panic mode and issue an out-of-band emergency fix like that must have meant that it was a rather huge threat; bearing in mind their usual complacency over some impending threats.

Even if you’re a Windows user who hates Microsoft Update and would rather stick pins in your eyes than use it – And there are a few of those around for some reason – I do suggest that just this once you break a habit of a lifetime; for your own and possibly other people’s sakes.