EternalBlue

EternalBlue is a cybersecurity exploit discovered by the U.S. National Security Agency and later leaked by hackers. It targets a vulnerability in Microsoft Windows' Server Message Block (SMB) protocol, which allows computers to share files and resources across networks. By exploiting this weakness, attackers can remotely execute malicious code, gaining unauthorized access to systems. This exploit was notably used in widespread ransomware attacks like WannaCry, causing significant damage worldwide. Microsoft released patches to fix the vulnerability, but systems that remain unpatched remain at risk of compromise through EternalBlue.