EternalBlue exploit is known from recent ransomware attacks hitting hospitals, banks and thousands companies.
Vulnerability is recognized with the same SMB communication sequence that the exploit uses but no harm is done to systems. The application doesn't contain any malificious code. It implements SMBv1 protocol on top of TCP and reacts to a SMB response which indicates vulnerability.
Intended for users who wish to monitor the networks they own or have permission to. The developer of this app cannot be held responsible for how this app is being used. The app comes with no guarantees.