Microsoft recently purchased 169 PCs from shops in China to study the market; all of the PCs were running pirated copies of Windows. Surprisingly, 91 percent of the PC came with malware or other security vulnerabilities, Computerworld reports.
59% were infected with malware, and on 72% of the PCs, the Internet browsing settings were altered intentionally to send users to scam and phishing websites.
The PCs Microsoft bought included well-known brands like Dell, HP, Lenivo and Acer. Pirated Windows OS is installed by a third party who preloads Windows over the non-Windows OS that are originally on these machines when they leave the factory.
It might be possible that even the third party who preload the pirated Windows OS is not aware of the OS being infected. They might be just cloning an infected version to all the PCs they are selling. I have seen so many cracked copies of Windows on BitTorrent in which Windows Update is disabled to prevent Microsoft from detecting the crack which get progressively more vulnerable to malwares as security updates and patches are released by Microsoft on every second Tuesday of each month.