WannaCry ransomware. What you need to know.

On 12 May 2017 the WannaCry ransomware campaign exploited the SMBv1 vulnerability (MS17-010) to rapidly spread across corporate networks worldwide via TCP ports 139 and 445, causing widespread disruption. The report outlines Microsoft emergency patches and mitigations (apply MS17-010, block SMBv1 and ports 139/445), and lists Zscaler detection signatures, in-line AV names, and sandbox/SSL inspection measures to detect and block the malware and post-infection activity.