All trojans that access the Internet do so via one of the many ports on your machine. Ports are thus a key vulnerability on any Internet-connected PC. Port scanning is used to find weaknesses in a computer or network by scanning or probing system ports via requests for information. This PestPatrol technical white paper defines ports and trojans, and provides a useful list of ports commonly used by trojans.

For more information on Ports and Trojans,
visit the PestPatrol Web site.