During a port scan, which type of attack is likely associated with a service running on TCP port 1433?

TCP port 1433 is the default port used by Microsoft SQL Server for client connections. When a port scan is conducted and identifies activity on this port, it indicates that an application likely associated with database services is running. Attackers often target SQL Server installations by exploiting vulnerabilities to gain unauthorized access to sensitive data, perform SQL injection attacks, or execute arbitrary commands.

The association with Microsoft SQL Server is significant because threats to database services are a common concern in cybersecurity. Attack techniques may include attempting to access databases or exploiting known vulnerabilities in SQL Server configurations.

The other options represent different services with their respective default ports: the Apache Web Server typically runs on port 80, FTP services commonly use ports 20 and 21, and SMTP services run on port 25. Since the question specifically addresses port 1433, the most accurate answer pertains to the service directly associated with that port—Microsoft SQL Server.