12345
NetBus / Custom Apps
Critical RiskTCP/UDP — Security & VPN
Port Overview
Port Number
12345
Service Name
NetBus / Custom Apps
Transport Protocol
TCP/UDP
Category
Security & VPN
Security Risk
Critical
Port Range
Registered (1024-49151)
What is Port 12345?
Historically associated with NetBus, an early remote administration and trojan tool from the late 1990s. Still flagged as suspicious in security scans when found open unexpectedly. Also used by various custom and development applications.
TCP/UDP
Security & VPN
Security Considerations
Port 12345 (NetBus / Custom Apps) is classified as critical risk. This port should not be exposed to the public internet. The service transmits data without encryption, making it vulnerable to eavesdropping, credential theft, and man-in-the-middle attacks.
Recommendation: Block this port at the firewall. Use encrypted alternatives (SSH, SFTP, HTTPS) instead.