The article says the backdoor has been present for "5+ years". Microsoft's acquisition of Skype was completed in Oct. 2011 (just over 5 years ago). Based on the

The article says the backdoor has been present for "5+ years". Microsoft's acquisition of Skype was completed in Oct. 2011 (just over 5 years ago). Based on the timing, that seems unlikely unless MS's first order of business was to backdoor Skype.