...
Was Windows XP the only OS affected? Or the newest ones too?
The newer ones are also affected. The difference is that Windows XP was not patched. Windows XP by the way still accounts for over 7% of market share This also illustrates a significant
additional failing in the proprietary software business model. When the manufacturer chooses to no longer support the proprietary software nobody else can. This creates an additional breeding ground for malware infarctions.