Windows XP reached its end of life on April 8th, 2014, and even though it no longer receives security updates, more people still use the operating system. Windows XP is used by 0.84% of the people running Windows, doubling Windows Vista’s current market share. A recently created ransomware decryptor illustrates how threat actors have to support Windows XP, even when Microsoft dropped supporting it seven years ago. Ransomware gangs are stuck supporting Windows XP in modern compilers, according to an Emsisoft CTO.
Source: https://www.bleepingcomputer.com/news/security/windows-xp-makes-ransomware-gangs-work-harder-for-their-money/

