Computer Virus

Computer virus is a self replicating piece of computer code that can partially or fully attach itself to computer files or application. Like any other program it contains instructions that tell your computer what to do. But unlike an application, a virus usually tells your computer to do something you don’t want it to do. Computer viruses are the common cold of modern technology. They can spread swiftly across open networks such as the internet, causing crores of rupees worth damage in a short span of time. If you are lucky, a virus will execute only a “personality quirk” such as causing your computer to make seemingly random bleeps. But some viruses can bee very destructive; they can format your hard drive, overwrite your hard drive boot sector, or delete files and render your machine inoperable. Five years ago, the chance you had receive a virus over a 12 month period was about 1 in 1000; today, your chances have dropped to about 1 to 10.

• Viruses enter your system via email, downloads, infected floppy disks, or hacking. By definition, a virus must be able to self replicate to spread.
• Thousands of viruses exist, but few are found roaming, unchecked, across networks.
• Virus behavior can ranger from annoying to destructive. Sometimes even relatively benign viruses tend to be destructive due to bugs introduced by sloppy programming.
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Antivirus software can detect nearly all types of known viruses, but it must be updated regularly to maintain effectiveness.

Symptoms of a virus attack

Some common symptoms of a virus attack are as follows:
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• The computer begins to run slowly.
• Unusual messages and graphics appear on your screen for inexplicable reasons.
• Music, not associated with any of the current programs, begins to play.
• Some of the program and or data files have either been corrupted or become difficult to locate.
• Unknown files or sub directories have been created.
• The size/ dates of executable files change automatically.
• The computer does not remember CMOS settings.
• The disk volume label has been changed mysteriously.
• The sizes of total and free memory are hanged unexpectedly
• The hardware devices begin to exhibit unusual behavior.

Antivirus Software

Virus experts have recorded more than 40,000 viruses and their variant strains over the years, though only about 200 of those viruses are actively spreading in the wild. While most viruses are just annoying time wasters, the ones that do deliver a destructive payload are a real threat.
Viruses have been around since the early 1960s, almost the same time when the early computers came into being. However, until the 1980s viruses were largely laboratory specimens, crated by researchers and released in a controlled environment to examine their effect. When viruses first appeared in the wild in the 1980s, they spread slowly and passed via the sneaker net”; floppy disks traded by people and shared between computers. Later on, widely available internet and email access hastened their spread. Two years ago, the advent of viruses that spread rapidly via email significantly increased the odds that an average computer user would confront a virus. E-mail viruses today account for about 80 percent of virus infections and can infect thousands of machines in a matter of minutes.

How did I get Virus, anyway?

You get a virus when you copy virus infected applications or files to your computer. The virus code inside the infected application or file gets activated when you run the application or open the file. How do you copy infected files is irrelevant: viruses don’t care if you get them as an email attachment, a download, or via a shared floppy disk. However, email attachments are the most prevalent and easiest mode of virus transmission. Once you open an infected file or application, the malicious code copies itself into a file on your system, where it waits to deliver its payload whatever programmer designed it to do to your system. Simply deleting the email after you open the attachment won’t get rid of the virus, since it has already entered the machine. A virus writer can set the payload to trigger immediately, at a present future time or date or upon the execution of a specific command, such as when you save or open a file.