SMB

High Risk

TCP — File Transfer

Port Overview

Port Number 445

Service Name SMB

Transport Protocol TCP

Category File Transfer

Security Risk High

Port Range Well-Known (0-1023)

What is Port 445?

Server Message Block. Provides shared access to files, printers, and serial ports over a network. Direct hosting of SMB over TCP without NetBIOS. Targeted by WannaCry and EternalBlue.

TCP File Transfer Commonly Used

Security Considerations

Port 445 (SMB) is classified as high risk. This port is a common target for automated scanning and brute-force attacks. If you must expose it, restrict access to known IP addresses.

Recommendation: Use firewall rules to whitelist trusted IPs. Enable rate limiting and intrusion detection.

Related Ports — File Transfer

20 FTP Data 21 FTP Control 69 TFTP 82 XFER Utility 115 SFTP (Simple FTP) 117 UUCP Path 139 NetBIOS Session 152 BFTP