First, let me give you some definitions before we start.
Viruses - A virus is a small piece of software that piggybacks on real programs. For example, a virus might attach itself to a program such as a spreadsheet program. Each time the spreadsheet program runs, the virus runs, too, and it has the chance to reproduce (by attaching to other programs) or wreak havoc.
E-mail viruses - An e-mail virus travels as an attachment to e-mail messages, and usually replicates itself by automatically mailing itself to dozens of people in the victim's e-mail address book. Some e-mail viruses don't even require a double-click -- they launch when you view the infected message in the preview pane of your e-mail software [source: Johnson].
Trojan horses - A Trojan horse is simply a computer program. The program claims to do one thing (it may claim to be a game) but instead does damage when you run it (it may erase your hard disk). Trojan horses have no way to replicate automatically.
Worms - A worm is a small piece of software that uses computer networks and security holes to replicate itself. A copy of the worm scans the network for another machine that has a specific security hole. It copies itself to the new machine using the security hole, and then starts replicating from there, as well.
Viruses, worms, Trojan horses, botnets, malware and spyware are human-made software programs created specifically to wreak mischief on personal computers and networks. They are so rampant and many nowadays, it has become very "normal" to get a virus in your computer. These viruses start small. All it takes in sometimes just one click to open an attachment from an email and the results can be very disastrous. In January 2004, experts estimate that the Mydoom worm infected approximately a quarter-million computers in a single day. Back in March 1999, the Melissa virus was so powerful that it forced Microsoft and a number of other very large companies to completely turn off their e-mail systems until the virus could be contained. In January 2007, a worm called Storm appeared -- by October, experts believed up to 50 million computers were infected.
Quick, swift, disastrous, or impressive? Most viruses or worms are very simple and harmless in nature. Usually, they just irritate a person by slowing down the entire computer system. However, they could be extremely dangerous and expensive as well. n 1988 a student at Cornell University sent out a virus out by accident, infecting more than 6,000 computers in minutes, nearly bringing the Internet to its knees. The "I Love You" virus caused over $1 billion USD in lost productivity as it crippled e-mail systems worldwide in 2000. And a worm called Conficker hobbled 15 million computers in 2008 and continues to do damage.
Therefore, there is a need for one to start protecting themselves against these virus, worms, trojan horses, etc threats. They can do this by installing free anti-virus softwares, or buying them to prevent any viruses from infiltrating their systems and destroying their work.
What I would suggest would be these few steps that I have managed to find on an online article:
1. Install an anti-virus/anti-spyware program. Anti-virus/anti-spyware software will stop malicious code from downloading and installing onto your computer while you peruse the Internet. Known as viruses, worms, or spyware, this malicious code can destroy important files and render your computer good for only one thing: sending sensitive data back to the server of an identity thief.
2. Don’t store sensitive data on your computer in the first place. Should your computer get infected with a virus, worm, or piece of spyware, you can thwart the individuals responsible by not storing your personal information on your PC so that when and if your computer does send back data – it won’t be anything valuable. Hackers look for things like full names, social security numbers, phone numbers, home addresses, work-related information, and credit card numbers. If these things aren’t saved onto a computer, there’s nothing critical to worry about other than restoring your computer to a non-virus condition.
3. Don’t open files without scanning them with an anti-virus/anti-spyware program. In the past, the warning was to avoid opening files from people that you don’t know. Today it’s really not safe to open files from anyone (without scanning the files) because that’s how viruses get spread – through files – even by mistake. So even though your co-worker may have emailed a funny video, it’s no more safe to open than a video downloaded from a complete stranger. Be safe and scan each and every file you download from the Internet or receive through email regardless of where it came from.
4. Create a barrier between your computer and prying eyes. Anti-virus/anti-spyware programs are only effective after the effect. But you can prevent identity theft from occurring by installing a firewall. A firewall is software that checks all data entering and exiting a computer and it then blocks that which doesn’t meet specified security criteria (user-defined rules).
5. Don’t click on website links in spam messages. In an effort to obtain personal information, some spammers will send email that asks you to click on a link. The email messages are often disguised as important messages from well-known online establishments, and they often try to scare their readers into clicking links with threats of closing an account of some sort. Sometimes the links are harmless and attempt to con the reader into volunteering personal information (credit card number), but other times the links attempt to download harmful software onto a computer.
Your best protection against computer crimes is your own knowledge. Hopefully the suggestions above will prompt you into taking appropriate action and into protecting your computer with the suggested tools. In doing so, you’ll not only protect yourself, you’ll prevent the spread of these malicious activities and protect others at the same time.
