The Server Message Block 1.0 (SMBv1) on Microsoft Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, 1607, and 1703, and Windows Server 2016, allows a remote code execution vulnerability when it fails to properly handle certain requests, aka "Windows SMB Remote Code Execution Vulnerability".
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-11780