Security on Cablenet

Inderjeet S Sodhi



Nitin entered his cousin sister’s room and noticed her working on the computer. He was visiting them to spend a few days after exams. His presence was acknowledged and greeted by Natasha with a smile and a short “hi!”. Realizing the possible importance of her task, he quietly sat down on the bed beside the computer without disturbing her. After a few seconds of silence, he asked, “Sis, have you put the computer to some other task also?”. Surprised and worried at the same time, she replied in negative. However everyone in the family knew that Nitin, a class IX student was a sort of computer “geek”, much ahead of others not only of his age-group but even the older generation. This prompted her to enquire, “Why did you ask?”. “Well, something is wrong with your computer.”, he was quick in responding. Seeing his confidence, she asked him for details. He told her that her HDD LED was blinking continuously, in fact almost “always on” and her cursor was often changing to the hourglass one. She quickly closed her work and allowed him to inspect the system. It was high-end computer on Windows Millennium installed with a recently installed net connection via cable. In a few minutes, he showed her on the screen, 14 users connected to her system - some of them copying files to their systems. These mostly were MP3 and Video files but two of them were copying her personal files from the default “My Documents” Folder. Horrified, she quickly shutdown the computer and requested him for help.



The names here have been changed but the incident happened in real. Not everyone is as lucky to have a geek cousin. The demand for stable Internet connections and higher bandwidth has led to the enormous success of the so-called Cable-Net. Actually Cable net in India is basically an extended LAN over Cat5 cable, and not what technically is Internet over (co-axial) cable. Decreasing costs of networking equipment has further made it possible for such services to be made available at cheap rates. These connections are really stable and bandwidth of upto 10 MB (100 MB in some cases) is possible over the same cable. Bandwidth can be adjusted as per the requirement of the individual connection without any changes to hardware. On the down side, this however also opens doors to security risks that are usually prevalent in the corporate world. Whatever be the reason, Devils’ minds now have wider accessibility to try “new” things.



But is it really so unsafe? In one word, No. Compare a computer system to a house. You get a new house constructed, get fixtures and fitting installed as per your own liking and then buy furniture and upholstery to your own taste. Similarly, you buy a computer to your own budget, have extra things like TV tuner and 3D game cards plugged in, get desired accessories and then get software loaded to your own specific needs. Almost everything is same except probably two things. When you get the house constructed or buy one, you check for the safety and security measures. It is made sure that all windows have grills, outer walls have barbed wire and pieces of broken glass fixed on them. Despite all this checking, you never leave your home without locking it. In case of your computer, however, these two things are seldom taken care of. On the contrary, people leave their computers on, with instant messengers running, so that family members and friends can buzz them whenever they get online. If the system is secured, it does not matter even if you leave it on all the time. But otherwise, it may become a cause of shock, depression or even embarrassment in some cases.



After all software is loaded, one needs to ensure that all updates and “patches” have been installed. Hackers and viruses use this ignorance as a platform. Once a security flaw is publicized, malicious people start using the flaw for their own goals. To make these ineffective, updates are required. Most vendors provide these updates for free. Most of us update their antivirus data files almost everyday but seldom update the core files. Antivirus software can help in identifying the virus after it has arrived in your computer but updates can plug the “holes” preventing these viruses land on your computer. For example, a notorious search engine used one of the flaws of Internet Explorer to download their files without letting the user know. When users opened the malicious webpage, a file was downloaded and the default search page was repeatedly set to its own webpage. Antivirus programs soon started identifying the downloaded file as a Trojan and deleted the same if configured to do so. If Internet Explorer is patched, the files won’t get downloaded at all.



In case of Intrusion also, it is possible to “barb-wire” your computer. By installing a firewall, about two thirds of risks can be reduced. A firewall acts as a gatekeeper, allowing only permitted or outbound connections. Imagine it to be a strong and high stone wall with continually burning fire at the top. Intruders cannot access your computer from outside without permission. However, care should be taken while configuring the firewall. Too rigid rules can hamper normal activity while too loose ones can allow others to access the resources. Besides these, file and print sharing should not be allowed on stand alone systems. If there is an internal network that uses file and print sharing, then File and Print Sharing binding should not be enabled on the particular network card to which the ISP is connected. At the time of setting up the network, there should be a unique domain or workgroup assigned to the internal network. Also, NETBEUI should be disabled for that card. This will also prevent your computer to send unnecessary traffic searching for port 137. Some free firewalls for personal use are(in random order):


ZoneAlarm by ZoneLabs (

Kerio Personal Firewall (

Sygate Personal Firewall (

Norton Personal Firewall (

Outpost (

Look’n Stop Lite (



The ISPs should also act in a responsible way and make their customers aware of security risks and by helping them overcome these. With proper attention to security aspects and a few easy-to-follow measures, one can enjoy the unlimited options of broadband Internet revolution.