Technically speaking, communication ports can be defined
as access points in a computer or a device thoroughwhich
information (both inbound and outbound) is transferred
between the computer and external resources(via TCP/IP).
IT networks then, including the Internet, are really
computers that are inter-connected through their
corresponding ports, through which they can make
queries or respond to queries sent from other computers.
The communications ports in computers make it possible
to browse the Internet, send and receive email, or download
files from FTP servers. Unfortunately, with time they
have also become one of the main channelsthrough which
viruses and hackers can try to achieve their malicious
aims. For example, there are viruses that can directly
enter computers through communication ports without having
to use traditional means of propagation,such as email.
They can also be used by many Trojans to communicate
with hackers or create backdoors to letan attacker take
remote control of the computer.
Protecting communication ports in computers that connect
individually to the Internet -i.e. those that are not
in anetwork- is best achieved using a personal firewall.
These applications monitor the traffic circulating through
the communications ports, blocking anything suspicious
from entering. There are many available on the market
and most can be configured only to allow connection to
the Internet for programs that frequently do so, such
as browsers, mail clients, etc. and deny access to any
other applications. This also prevents spyware, which
normally uses ports to send information out to third-parties.
In order to protect ports, companies with mid to large
sized networks should consider the possibility of using
a firewall server, as this will prevent attacks through
ports in the rest of the computers that make up the network.
Small to medium-sized companies, however, only need a
personal firewall in each of the computers in the network.Finally,
the tightest security is obtained by combining a firewall
with adequate antivirus protection. This will blockviruses
sent by email, for example, which are capable of terminating
the processes belonging to firewall applications, leaving
computers defenseless against future attacks through
article from Panda Software (http://www.pandasoftware.com)