Key Management Service (KMS) is a legitimate technology used by Microsoft to activate software in volume-license environments (such as large corporations or educational institutions). Instead of individual PCs connecting to Microsoft servers, they connect to a local KMS server within the organization to verify their license.
Can often renew licenses without a constant internet connection. Supported Software kms activation helper v15 64bit exclusive
Many versions are flagged by Windows Defender as "HackTool:Win32/AutoKMS" or Trojan-type malware. They often require users to before execution. Legal Key Management Service (KMS) is a legitimate technology