Ultimate Computer Virus Resource Guide

Posted on 05/10/2018 by Jonathan O'Brien

Viruses are nasty, self-replicating parasitic bugs-kind of like the flu-but infecting your computer system. Viruses damage computers because they attach themselves to files, replicate and spread. Some do little more than create an annoyance; some are designed to create serious damage to your computer's programs and performance. Consider all viruses harmful-and like the flu, do what you can to prevent infection and wipe it out as soon as you can.

How Do Viruses Affect Computers?

Most viruses were passed from one computer to another because infected floppy disks were inserted into disk drives and copied onto computers. People tended to use these disks over and over again to reboot systems, to share files, or because they were fairly expensive, overwritten and used again. Today's viruses are most easily spread by email, activated when message attachments are opened, or through ads on websites.

Types of Viruses

Viruses are a type of malware, another name for malicious code that infects operating systems. Many disruptive and damaging programs get lumped under the term viruses, like worms and Trojan horses but there are some stark differences. Worms allow hackers to get remote access to your computer. Worms are self-replicating like a virus, but they have no need to attach themselves to any of your files in order for remote access to be gained. Most worms don't alter files, but some like the Mydoom worm create backdoors for new worms to enter through later-in this case, Doomjuice. Most just allow remote access to send spam or consume some of your bandwidth, both more annoyances than damaging.

Trojan horses do not replicate like viruses. Users think they are downloading or opening programs to do one thing, not realizing that by opening and using those programs, that they have introduced a dangerous covert operation known as a Trojan horse within their operating system. The effect is the same as the original Trojan Horse of Greek mythology. Greek soldiers gave enemy Trojans a wooden horse as a symbol of peace. Once inside enemy territory, Greek soldiers snuck out of the horse's belly and captured the city of Troy. Computer Trojan horses are no different-they do what you expect them to do and then something totally different happens. They require two-way communication, interaction between the user and the hacker, in order to target your system. This can result in spam, identity theft, viewing you through your internet camera remotely, and tracking your cookies and logging your keystrokes. Trojan horses account for over 80 percent of the malware in operation worldwide.

You know that you might have a virus if your computer is running slower than usual, if you get unexpected messages or sudden program openings, closings or shutdowns. You can tell if there is constant activity going on within your operating system if your modem or broadband light won't go off. This doesn't mean that you absolutely have a virus, but coupled with other viral symptoms, chances are you probably have something foreign going on in your system. Viruses erupting recently in North America include: JS/Tenia.d, Artemis!6D2857B6A911, W32/Sdbot.worm!mh!DDC54D27F27E and GenericPWS.aj.

How to Remove a Virus

Act quickly. Removing viruses should always be done from a non-affected computer or by working in safe mode on the affected computer. Most computers have antivirus software installed already. Make sure it is up to date. Don't delay updating when it prompts you to. Removing viruses and other malware can be tricky, so let your antivirus programs do the work for you if you can. If you don't have any antivirus software installed, you can find plenty that are free or available at reasonable cost. Don't assume that your antivirus software has removed the malware the first time, even if it claims to have done so. Always double check by shutting down your computer and rebooting. Then run it again. If it still comes back clean, you are good to go. If you have to remove the virus manually, expect to delete some files, but know what you are doing or hire an expert.

Preventing Viruses

Keep an eye on virus calendars and global virus maps that computer security firms like McAfee use to track activity and new threats. Calendars can indicate when new viral payloads are about to strike. Maps can let you know whether there is an elevated or severe threat to computer systems globally or in your own neighborhood. You can track by continent, infected files or computers during a certain time period. Many viruses have long, convoluted alphanumeric names; so most names get shortened to easy to remember names colloquially.

Prevent viruses by never opening unknown email attachments even by senders you know. Asking is one of the best ways to circumvent viral infection. Misspelled subject names, misspellings in the body of the email and email from out of the country should always be red flags to hit that delete button without opening. Exercise caution regarding downloading from the Internet. Only use trusted sources. Change passwords and logins on a regular schedule. Use your anti-virus software regularly-don't buy into the mindset that one type of operating system is more vulnerable to viral attacks than another. Some popular software includes McAfee, AVG, Symantec and Norton antivirus packages. Back up your files regularly.

• Virus Basics
• Virus Encyclopedia by Name, Discovery, Damage and Spread
• McAfee Virus Information, Threats and Calendar
• How Can I Know I Have a Virus?
• How to Remove a Computer Virus
• The Virus Wild List
• CompTIA Security+ Training
• Trojan Horses
• Defending Against Cyberwar