First of all we would like to know what exactly are virus, Trojan horse and worms. Viruses, worms, and Trojans are malicious programs which enter to your computer without your permission and knowing that can cause damage, information losses, privacies leak to your computer .They can also slow down the Internet connections, and they might even use your computer to spread themselves to your friends, family, co-workers, and the rest of the internet. The good news is that with an ounce of prevention and some good common sense, you are less likely to fall victim to these threats. Think of it as locking your front door to protect your entire family for example you will never open anonymous mails or attached file and always keep you computer security up to date like latest firewall, antivirus programs and etc.
What is virus? A computer virus, according to Webster's Collegiate Dictionary, is "a computer program usually hidden within another seemingly innocuous program that produces copies of itself and inserts them into other programs or files, and that usually performs a malicious action (such as destroying data)". Two categories of viruses, macro viruses and worms, are especially common today. Computer viruses are never naturally occurring; they are always man-made. Once created and released, however, their spread is not directly under human control. One example of a virus is the Anna Kournikova virus, which comes in the form of a picture sent through email.
What are worms? Worms are very similar to viruses in that they are computer programs that replicate functional copies of themselves (usually to other computer systems via network connections) and often, but not always, contain some functionality that will interfere with the normal use of a computer or a program. The difference is that unlike viruses, worms exist as separate entities; they do not attach themselves to other files or programs. Because of their similarity to viruses, worms are often also referred to as viruses. A well-known example of a worm is the ILOVEYOU worm, which invaded millions of computers through email in 2000
What are Trojan horse? Named after the wooden horse the Greeks used to infiltrate Troy, a Trojan horse is a program that does something undocumented which the programmer intended, but that the user would not approve of if he or she knew about it. According to some people, a virus is a particular case of a Trojan horse, namely one which is able to spread to other programs (i.e., it turns them into Trojans too). According to others, a virus that does not do any deliberate damage (other than merely replicating) is not a Trojan. Finally, despite the definitions, many people use the term "Trojan" to refer only to a non-replicating malicious program. An example of a Trojan horse is W32.DIDer. This virus has been found on the computers of users who have downloaded the popular file-sharing program Grokster.
What are the damages we are facing from viruses, worms, and Trojans?
What are the damages we are facing from viruses, worms, and Trojans? In august 2003, a record of major worms attacked the world wide web and brought 73% of email traffic to the world which wrecked up economics damages of billion of dollars. During that attack, the performance and connection speed of the world has been brought down and may also caused of computers loss power, servers and workstation slowing down or not responding. According to Clyde Hewitt, Principal,Phoenix Health Systems, Healthcare organizations that depend on the Internet, especially those running remote Application Service Provider (ASP) programs, may not be able to connect because Internet response time can be substantially degraded by the additional traffic created by infected emails. Corporate in the world are spending millions on dollars on cleaning worms and virus every year to prevent it happen again.
In a recent study by the Department of Trade and Industry in the United...