Combat with Viruses

Virus, Worm and Bacteria are the well known biological pathogens. In computer terminology, experts have termed them for malicious computer programs. In previous decades, these programs were supposed to be a computer errors or mistakes. But now, many passionate destructive programmers have coded such programs which are intentionally programmed to perform some destructive tasks. Their benefits are not
known. Although, their destiny is known to us and that is – Imprisonment. But question arises, why such programmers have chosen such a poor activity?

In my opinion, the reason behind such thinking is human nature. These people may
be unable to do anything good to become famous. That’s why they have chosen such
a wrong way to become famous. Obviously, that is also a kind of fame. In this article, you will find some precautions,
ideas and tips to get rid of such malicious programs. This article also provides
an introduction to such malicious programs.

A virus is a malicious program which is programmed and designed to take benefits of flaws in computer system including hardware and software components. The
resource to what each virus demands is CPU Resource. CPU resource can also be understood as
execution state of an application.

All the executables programs follow the following states -

(1) Dormant State

(2) Ready State

(3) Execution State

(4) Waiting State

Each executable program in the beginning gets dormant state. In this state, the executable is only stored in the secondary storage device (Hard disk, Floppy etc.). After the CPU Scheduler schedules
an executable file, executable program gets the CPU resource. Each application program
has to pass through all these states. For the same purpose, Operating system has the scheduler program that runs under the kernel to perform the execution of executable programs. Even a Virus
Program also follows through these states.
In MS-Dos and Windows based Operating systems .com, .exe are common executable files. Many
‘Trojans’ and ‘Cuckoo-eggs’ take benefit from this.

Trojans are the malicious programs, but, they cheat with the user by his own mistake. Such as,
any application program may store a program with the same name in a directory which is scanned by operating system shell
first. Such as System32 folder of Windows-2000 is first of all searched for presence of a file before
Winnt folder. Due to this, if you type an executable file without providing its full name, you may accidentally execute a different file that may be malicious.
Other option for such programs (Trojans) may be extensions of Windows operating system. A
‘.com’ is executed before ‘.exe’. I meant that if two files have the same name with only difference of extension, you may execute a
‘.com’ accidentally which may be a Trojan. One other method which is followed by
such Trojans is typing mistakes. But, GUI based operating systems where icons are followed, such mistakes
are rarely found.

Effects of Viruses:

Viruses not only utilize system flaws, but they also work with useful components of operating system. The best way for such programs is performing a loss to
computer systems by spreading themselves. This quality of viruses matches with biological viruses. I think,
this is the main reason why ‘Virus’ name was coined.

A virus may -

[1] Replace the system files and software executable with their own program.

[2] Delete some content or modify all the contents.

[3] Read you Address Book and mail the Virus program as a attachment to your friends and
groups.

[4] Eat-up all the system resource by acquiring memory (Memory-resident Viruses).

[5] Make the whole system state unstable or nearly stop working.

[6] Create a Bad Sector to hard disk which may be discarded by Operating system.

Most of times viruses act in such a stealth manner that user is unaware with
their functions. A novice user may not notice their presence and activity.
Sometimes experts also miss their activities. Actually, virus developers do not follow any common method
or technique. They are simple programmers who accidentally know some system flaws and
implement their code. They do not even think the effect of such activity.
Computer systems are installed many locations. This may installed in a Hotel, Office and even in Hospital. It may be installed in an ICU of a hospital. Think of a scenario, when someone
is dying only due to failure of ICU computer. This is a real shame on virus developers. If they can not do something good, why applying all
their frustration on poor citizens? Whom are you taking revenge from? I think, they are the heartless fellow who do not understand human feelings and they are
away from humanity. I have just one suggestion to them, meet a psychiatrist.

These programs are collectively called malicious programs. These are executables in various forms. Some VBA programs
with destructive nature are also one of these.

Virus : Any malicious program which creates multiple copies and performs any miscreant activity
within the system resource. They eat-up memory, replace or corrupt boot sectors of hard disk or stop a working systems.

Trojan : These programs resemble with viruses. But they have interesting way to make themselves executed. They take benefits of typing mistake or priority based system of operating system as discussed above.

Worm : Worm are network based programs that takes network based flaws into consideration. They spread themselves through network and generate serious problems in
server. They may affect big organizations to home computers with their execution. Their activities are similar as defined in previous point,
but they differ in their methods of spreading.

Bacteria : These malicious programs have just single intention of copying themselves many times. This causes lack of resource in the computer.
Due to severe space utilization, it becomes hard to work on such computer.

Spyware : Such programs spread through internet. They take useful information from the computer systems and send them to a web-server, which
is installed to know the secret user information. These programs are easier to develop,
implement and spread.

Botnet : Such programs are similar to spywares. But their mechanism is different. These programs are installed by Internet, the developer installs them in
many computers of the world and they have interest to copy
software and programs installed on computers of big organizations. They usually
send commands to other computer systems remotely. Once the central server sends a command through IRC, all the computers where botnets are installed, respond to it.

This was a brief information about malicious programs. Now I should come to the point,
what can you do to escape from them and rescue if you affected accidentally?

There are many precautions which can be taken to avoid viruses. I have enlisted some of the precautions, all of them are mandatory to follow -

(1) Do not store installable programs in hard disk.

Many times, we copy the installation program from CD-Rom of software to Hard-disk directory. Actually, most of viruses replace the executable programs with the virus program. If they affect your hard disk, you may accidentally install them.

(2) Install a virus scanning program and scan the executable files before
execution.

You must install any virus scanner program which can scan each file individually. This
would escape you from state where you could accidentally execute a program that is already virus affected.

(3) Windows users should not follow web-view of windows explorer.

Most of viruses replace the ‘Folder.htt’ with some ‘VBScript’. Each time you view a folder, you execute a virus
in background. Follow the folder option and replace the view of folder to ‘classic folder
view’.

(4) Use Full extension instead of Filenames only.

By default Windows Explorer is designed to hide the extension of known file types. This is the weak point. Actually, most of viruses that executed through e-mails
utilize this weakness. They may use the same icon of Microsoft Word to any executable file. You would take a file as Microsoft Word file which has
Microsoft Word icon. You may execute it with full confidence and accidentally affect your
system with a virus. Follow the ‘Folder Options’ of ‘Control Panel’ and uncheck the option in View tab that suggests –
‘Hide file extension for known types’.

(5) Keep better control on programs that are executed at system start-up.

You can follow System information from Program > Accessories > System Tools. Click Software Environment and then click Startup Programs. If you find any program that may be malicious, you can remove it from startup. There are two options for any program to execute at startup -

(a) Programs > Startup Folder.

(b) Windows Registry

You may easily remove a suspected file from startup folder by deletion. But Windows registry is bit trickier..

Anti-Virus programs are the best solution. There are many freeware anti-virus programs such as AVG, Avast and others. On the other hand,
you may install Norton Antivirus, PcCillin and McAfee which are famous ones. Use any one of them that suits your
requirements best. These anti-virus programs keep some patterns of file organization of a virus infected file and they match the same pattern to all the files stored in your system. They may track a series of viruses. If they find any virus during scanning, you are prompt to delete such files. You are also informed with the names of
viruses. Actually, these names are given by anti-virus programs itself. But names are common to all the
anti-virus application.
You should update your anti-virus software through Internet to make it efficient over new viruses. Most of
update versions are free of cost.

If you find some specific files affected by virus while scanning with anti-virus program. Remove them immediately. But, if you find that many files are affected and even system files are also corrupt. Save all the data files stored in boot drive (mostly C:) and store them in other partition of your hard-disk. Scan you boot sector with anti-virus program and if that is also affected, store your data files in a floppy disk or some other media. After this, power off your system, do not shut down properly in this case, there may be some files related with windows shut down process, affected with virus. Such program may also affect your recently secured data files. Next you do is re-installation of operating system. You should format the partition affected by such viruses. Do not install without formatting.

Some VBScript based viruses can be removed by deleting .HTT files. .HTT file keep the customized folder setting. Search these files
against all computer folders and then delete them immediately. You may also search them with clause of text containing as
‘VBScript’. This will affect only the view setting of all the folders of your computer. But, if you are already using classic view of
folders Option, you will automatically get rid of HTT files related problems.

Worms are real problems for the computer which are part of a LAN or intranet. Your Internet connection may also be LAN based. If you are not using firewall, Botnet and worms can perform their poor activities. Firewall is a software that can be installed to protect unauthorized access to your system through network and controlling incoming and outgoing traffic efficiently. Such program allow only those applications which are intended to use the Internet or access the network. One of the firewall software is – ZoneAlarm of Zone Labs. This product is
a freeware for home users. You need not be an expert. This program is by default well configured. Trusted zones are set into it which are the computers of the network which can make connection with you. You can lock the internet facility if you are not using it.

Actually, spywares make contact to any server to perform their activity, when they lose the connection, their effect becomes negligible. So, firewalls can be used to get rid of worms, botnets and spywares.

Anti-Spyware softwares are the other method to protect the spywares. Actually, spywares have a similar pattern to work. Making access to Internet and send the useful information and address book to their web-servers. They put themselves in start-up with the resembling name to a system file, such as rundll32.dll or Kernel32.dll. They masquerade with you and play silly game of breaking your privacy. They are not the one who delete something from your system, but, they are the one who want to perform something which can not be regained. Do not use Internet Explorer if you are entangled with again and again installation of viruses. Use Mozilla Firefox instead. Actually, being more powerful Internet Explorer allows execution of some scripts which may be harmful to your computer. Spywares are not the viruses, but, I keep them in malicious programs.

You should trace the reason of any virus infection. If you trace it properly, problem may be avoided in future. Anti-virus programs work to trace virus files,
but no one takes guarantee. Your awareness is above all. Overall, a virus is a program and it has its process in your computer. Use task manager to
track them and delete them on the spot. Scan your computer with such programs and do not click each executable, first scan the file,
then execute it. I have mentioned some of the precautions, but the list is long. One best precaution is to use registered
software only which follow some standard. There are many organizations for standardization. Products downloaded from good software companies do not contain any such problems. You can download such programs from registered companies site.

Overall, I can say –
“Precaution is better than cure.”

“One scanning a day, keeps Viruses far away”

Author: Som Dutt Tripathi
Article Source: EzineArticles.com
Provided by: Programmable pressure cooker

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