Do I have a virus? What is a computer virus? According to Wikipedia, "a computer virus is a computer program that can copy itself and infect a computer without permission or knowledge of the user."

There are many definitions of computer virus and there are also those that make a distinction between the terms virus, worm, and trojan, or trojan horse. However, the primary characteristic of a computer virus, that is, the characteristic that earns it the label of "virus" instead of simply malware is its ability to replicate itself and deliver itself to other computers. Technical distinctions aside, unless you're planning on tackling virus removal yourself, all you need to know is that they're all bad!

Computer viruses are usually designed to perform one or more actions referred to as the "payload." A typical virus payload would involve first, triggering some mechanism designed to copy the virus to other uninfected computers. Common methods include:

• Mass emailings of itself using the address book of the infected computer.
• Moving from computer to computer through open network shares (pathways from the hard disk of one computer to the hard disk of another computer through a local area network).
• Attaching to floppy disks, USB thumb drives, or other portable media that is moved from machine to machine.
• Sending itself through security holes in various inter-computer communications such as Instant Messaging or Internet Relay Chat (IRC).

In addition to this self-replicating behavior, many viruses also deliver a secondary payload that may be as destructive as wiping out all of your document files (KLEZ worm), or may be as benign as popping up a message that reads "I am hungry! Insert HAMBURGER into drive A:" (JOKER virus)

What are the symptoms? Sometimes when you have a virus it's obvious. Sometimes it's not. Here are some typical symptoms that our customers report:

• When I start up my computer, I get an error message that says I'm missing files.
• My computer is running really slow and it seems like it's struggling. Sometimes this is reported as a lot of hard disk activity, or "crunching." (You may also want to check out our spyware/malware page to learn how spyware or malware may cause similar symptoms, or our slow computer page for general information and other causes of slow computer performance)
• I opened an email attachment or clicked a link that I don't think I should have opened and now my computer is really acting weird (a surprising number of customers know exactly when and how they got infected because they realize immediately after opening that attachment or clicking that link, that their system has suddenly sprung to life and is running off to do the bad guy's bidding! If this is you, shut down now and get professional help!)
• Some of my friends have called or emailed wondering about an email they got from me that I never sent
• My virus scanner keeps telling me it found a virus over and over (if a virus is reported to be detected only once, your antivirus software probably has the situation under control. However, if your antivirus software repeatedly reports finding the same virus, you probably need some geek intervention!).

What can be done about it? Your best protection of course, is prevention, and nothing does this better than a single-purpose virus scanner with on-access scanning capability (this means in addition to scanning on a schedule, it constantly scans any files that are opened or accessed), and of course, keeping it updated. The good news is, most scanners do a reasonable job of this, and updates are usually pretty well automated. The bad news is, no protection is 100% and a lot of more sophisticated viruses incorporate antivirus-killing techniques that disable or corrupt your antivirus program, rendering it useless. If you even suspect a virus, the time to act is now! And if you're using a commercial virus scanning product like Mcafee, Norton,or others, you may already know that sometimes it takes more than what those packages have to offer to really get a virus under control on your system.

How can Geek Housecalls help? For professional assistance in identifying and ridding your system of viruses, consider a call to Geek Housecalls. Your geek arrives armed with a battery of proven specialty tools for the eradication of viruses. More importantly though, your geek specializes in the surgical removal of registry keys and system-level files that are associated with viruses, and that are not always effectively removed by available tools. With this one-two punch of tools and know-how, we are able to clean up most machines without having to resort to a rebuild.

Sometimes however, viruses have done more damage than is practical to try and reverse by typical cleanup methods. In this case, your geek may recommend a complete rebuild of your machine including re-installation of windows. Either way, your problem will be solved, system performance restored, preventive tools offered and friendly advice given, leaving you with a well-behaved computer and a smile!