Monday, August 21, 2000		Article

Programmes that monkey about in computers

Most of the computer-users might be amused to get a message flashed on their screen: "Bandar (monkey) found in the system". Imagine the user’s plight when he realizes that it’s a virus, which is responsible for the message. No joking! This bandar can actually start some monkey business with the system. That’s not funny.

Most persons are still ignorant about computer viruses. These are actually computer programmes, created intentionally by software experts to disrupt the performance of other computers.

Like actual viral diseases, such programmes are contagious and spread fast. These programmes are written in such a way that they spread easily without getting noticed.

Viruses can be transmitted as an attachment to e-mail, or by downloading infected programmes from other sites. They can also be present on a diskette or a CD. Since, normally they remain hidden, as they cannot be seen by directory command or under the Windows explorer in majority of the cases, the source machine-user is often not aware of them. Some virus get activated as soon as their code is executed on a PC, or any action which activates the virus is performed; other virus lie dormant for sometime and get activated after some code is executed on them.

If the computer is affected do not transfer data from it. The virus may actually attach itself with the data and reaches yet another destination.

Virus attack may vary in intensity depending on its programming. Some are deadly and are capable of crashing the whole system, without any recovery. Or they may eat up the data, mainly in the form of .EXE files, so that when you access them, you find that a great deal of damage has already been done.

Several viruses may affect the memory of your system and even corrupt the system. Others may not be so harmful. But these may be "mischievous". There are some viruses, which will seek the e-mail address and will send mails to everyone registered in the address book. It may be offending at times, when either your secret data becomes a public property or some objectionable material is sent through your e-mail account to everyone in your address book. There are some viruses, which simply display some stupid message on your system.

There are three main categories of virus:

File infectors: The virus, which attacks the specific files directly, are commonly referred as file infector virus. A majority of these attach themselves to the programmed files and target the .com or .exe files. There are some viruses, which can affect any programme for which execution is requested, and the common file names in this case are .sys, .ovl, .prg, and .mnu files. If these files work as carrier of the virus, then they automatically get loaded when the programme is loaded. Other file infector virus does not attach themselves with the executable files, but they are transmitted as an e-mail attachment and are normally in the form of scripts.

The system or boot-related data infectors: These viruses are deadly as they attack the system to destroy the basic system file, including the boot record. The system may not start as these destroy the executable codes in the systems directory. They also affect the DOS boot sector on floppy drives or the Master Boot Record on hard disks. These viruses normally spread through the infected floppy disks and the CDs. Even if an infected floppy or a CD is in the system and the operating system is running, chances are the virus could get transferred. It is for this reason that formatted floppies are preferred for use at a new place.

Macro viruses. The third category of virus is the macro virus. It is the absolute misuse of an otherwise useful language, Visual Basic. These viruses normally get transferred through an e-mail and affect the Microsoft-based applications, like Microsoft Excel, Access, and Winword.

They are most common and are relatively easy to kill.

Another kind of virus, which is not so deadly, is Trojan Horse. In computers, a Trojan Horse is a programme in which harmful code is contained inside an apparently harmless programming or data, in such a way that it can get do its chosen form of damage, such as ruining the FAT (file allocation table) on the hard disk. On the brighter side, a Trojan Horse has even been used to kill a virus in the computer as it is nothing but a computer programme, which becomes a virus when it gets distributed to other computers.

Time and again, new virus hit the computer world to create havoc in the computer world till some solution is developed for them. Recently the love bug virus attracted the global attention, when it stalled thousands of computers worldwide.

The solution is not so difficult to seek. The solution lies in precautions and the use of anti-virus software. Avoid using floppies from unknown source. If you should use them, scan them properly. Do not entertain unsolicited mails and do not open any e-mail attachment, if you are not sure about the sender. Also avoid downloading files from unknown Net.

Besides exercising caution, get a good virus scanner like Norton, Dr Solomon, or McAffee virus scanner for regular scanning.

— V.V.