Much of the early focus on Windows XP was the result of the UK’s National Health Service, one of the earliest and most damaging WannaCry victims. A number of outlets blamed the NHS infections on computers running Windows XP, leading to widespread concern over Microsoft’s failure to release a patch. The NHS itself vigorously denied the claim, saying fewer than 5 percent of the service’s computers ran Windows XP at the time of the attack. In light of the latest Kryptos research, it’s plausible that unpatched Windows 7 systems were more of an issue for NHS.
In the days after the attack, Microsoft drew significant criticism for its failure to issue a public patch to protect Windows XP against WannaCry.
Tuesday, May 30, 2017
"Windows XP computers were mostly immune to WannaCry"