Port Scanning

Posted: October 17th, 2013

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Port Scanning

A port with reference to a computer refers to a place in which information goes in and out of a computer. Port scanning is a technique used by hackers on the internet to access information from one’s computer. They look out for these vulnerabilities so that they can access information from an unsecured computer. They employ the use of malicious programs and Trojan horses to access your computer through open ports (Salomon, 2010).

A port scanner works by identifying which TCP (Transmission Control Protocol) and UDP (User Diagram Protocol) ports that are open and vulnerable. These two ports make up the TCP/IP that is used universally to communicate with the internet. It does this by scanning through the whole computer and finding the ports that are connected to the system’s TCP/IP. Though there are other commands that can do the same, they are not as effective as port scanning. For instance, netstat command finds open ports in a local Linux UNIX systems but it cannot be used across a network remotely. Port scanning is thus the best method that hackers use to access information from other computers.

Most web servers are supported by proxy servers, which are commonly targeted by hackers. This is because, in proxy servers, all the web pages are directed from a single server, which supplies all pages that have been visited recently. By doing this, it improves the computer’s performance. To achieve this, computer servers need to be misconfigured, thus providing an ideal situation in which hackers can take advantage of an unsuspecting computer user. A way in which hackers access one’s computer is by issuing a “denial-of-service” attack thus preventing the user from accessing his or her computer.

Port scanning is hard to eliminate. As long as a computer user wants to access the internet, he will always have this threat to worry about. Certain actions can be taken to avoid such attackers. First, install an anti-virus to lock out unwanted users. Also, update windows regularly so that open ports and vulnerabilities are found and closed or dealt with. One can also install a firewall that monitors all the activities on you computer. The network security applications are configured in such a way that an alert is sent to administrators if they notice connection requests from a wide variety of ports but from a single host. Lastly, the best way of getting rid of these threats is being updated on the new ways they come up with to hack computers. Many internet sites provide users with useful information (Scambray, McClure and Kurtz, 2001).

As technology reinvents itself, port scanning can also be used by computer users to guard them from looming threats of hackers. With port scanning software such as Nmap, foundstone vision and portscan 2000, a system, network, or security administrator can ensure groups of hosts are all secure at a time. All a user has to do is scan his or her computer and close all the ports that are not currently being used. This reduces the chances of a computer being hacked, as the user is aware of the ports that are open. Therefore, with this knowledge users are able to block out hackers from attacking them (Lyon, 2008).

Reference:

Lockhart, Andrew. Network Security Hacks. Sebastopol, CA: O’Reilly, 2007. Print.

Lyon, Gordon F. Nmap Network Scanning Official Nmap Project Guide to Network Discovery and Security Scanning. Sunnyvale, CA: Insecure.Com, LLC, 2008. Print.

Salomon, D. Elements of Computer Security. New York: Springer-Verlag, 2010. Print.

Scambray, Joel, Stuart McClure, and George Kurtz. Hacking Exposed Network Security Secrets & Solutions. Berkeley, Calif: Osborne/McGraw-Hill, 2001. Print.

Walker, Bruce J, and Ian F. Blake. Computer Security and Protection Structures. Stroudsburg, Pa: Dowden, Hutchinson & Ross, 1977. Print