Computer Viruses


 

COMPUTER VIRUSES

By: Rosemarie C. Ramos                          IZPO Marketing Staff

So what are these viruses? Why do we need to get rid of it? Well, if bacteria or germs can destroy your body system from functioning well and may make you disoriented, computer viruses can damage your computer and the files that were stored in it.

Only few really know what virus is. Viruses are programs that replicate themselves inside a computer. It is also called worms or malicious programs designed to infect and gain control over a computer without the owner’s knowledge.

Viruses replicate themselves inside a computer. It can’t do any harm to a computer when a user simply browse a Web or opens an E-mail.

Viruses attack in an unexpected way. It is usually hiding in an E-mail attachment and when the receiver of the said E-mail opens it, that is when the viruses start to spread its wings and make a possible damage to your computer and your files.  It will start to replicate and may carry out damaging instructions.

To explain how a virus attack happened is by taking the so-called Melissa virus. Melissa appears inside an E-mail Microsoft attachment. In the E-mail, there is really nothing dangerous to suspect about because the sender appears to be from someone known to the recipient or in his/her address book. But when the recipient clicks on the attachment and found herself reading a word document, the virus then works by sending the same attachment to the first 50 names in the address book. So don’t be surprised when your friend called you and said that you are sending her this kind of attachment which has nothing to do about any topics you were talking about lately.

Viruses do not appear as an E-mail attachment alone. It also appears in portable devices, websites containing malicious scripts and file downloads. A computer virus attaches itself to the host files and always activate whenever you open the infected files. The virus can replicate itself and then infect the other files in your computer causing more damages.

What is more alarming is that viruses attack in different methods. Those who make these viruses continually add new twists.

DIFFERENT KINDS OF VIRUSES

Macro Viruses

These viruses use application that contains macros such as doc, pps, xls and mbdb. Automatically, they infect files with macros , templates and documents which are in the file. They are hidden in the files sent via E-mail and networks.

Macro viruses are : Relax, Bablas, Melissa A and 097M/Y2K

Memory Resident Viruses

This kind of virus gets activated every time the OS runs and ends up infecting other opened files. It is hidden in RAM. It usually fix itself inside the computer memory .

Memory Resident Viruses include: CMJ, meve, randex and mrklunky

Overwrite Viruses

These types of viruses erases any information in a file they infect, and once got infected it may become partially useless or totally cannot be use at all.

Overwrite viruses include: Trj Reboot, way and trivial.88.D

Direct Action Viruses

These viruses replicate and become active once executed. The viruses act by infecting the files in the directory or the folder specified in the AUTOEXEC.BAT. It is usually found in the hard disk’s root directory and they are changing locations.

An example of Direct Action virus is the Vienna virus.

Directory Virus

This is also known as the cluster virus or file system virus. It infects computer’s directory by changing the path indicating file location. It is located in the disk but affect the entire directory.

Directory virus include dir-2 virus.

Web Scripting Virus

Most web pages include some complex codes in order to create an interactive and interesting content. Such a code is often exploited to cause certain undesirable actions. They mostly originate from the infected web pages or browsers.

Web Scripting Viruses Include:  JS Fortnight

Multipartite Virus

Actions of this kind of virus vary depending on the OS installed and presence of certain files. They tend to hide in the computer’s memory but do not infect the hard disk.

Multipartite Viruses Include: flip, invader and tequila

FAT VIRUSES

These virus attacks the file allocation table ( FAT ) which is the disc part used to store every information about the available space location of files .

FAT Virus example is the link virus.

COMPANION VIRUSES

As the term implies, this kind of virus accompany other existing files once inside the computer. It infect files through direct action and as a resident type.

Companion viruses are : Asimov.1539, stator and terrax.1069

POLYMORPHIC VIRUS

This kind of virus uses different encryption and algorithms. And that makes it difficult for the antivirus software to locate them.

It includes:  Marburg, Tuareg, Satan bug and elkem

WORM

This is similar to a virus and has the ability to self-replicate leading to negative effects in the computer.

Worm viruses are: lovgate F,  sobig D, trile C, PSWBugbear B, Mapson

TROJANS

It can illegally trace important login details of users online.

EMAIL VIRUS

This is a virus spread via E-mail.

BROWSER HIJACKER

It can be spread in many different ways including a voluntary download. It infects certain browser functions especially in form of re-directing the user automatically to certain sites. An example is the cool web search.

BOOT INFECTORS

This includes the boot sector plus master boot record types. They infect the hard disks.  This is very common when floppy disks are still in used. The brain virus is the first virus ever created.

WHAT TO DO IF YOU SUSPECT A VIRUS IN YOUR COMPUTER?

Prevention is better than cure as they say. First thing to do, when you buy a computer is to make it secure from virus. So install an anti-virus software. With anti-virus, your computer will be protected and so are the personal information in it.

Second thing to do is try to be vigilant and be careful when opening an E-mail or any attachments. Screen your E-mails first and delete suspicious-looking and unwanted messages. Do not just download any attachments without examining if it came from a valid known recipient.

And lastly, make sure that your system is up to date and keep back-ups.

avast! 4 WHS Edition

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