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Engineering LibreTexts

12.9.1: Computer Viruses

  • Page ID
    69394

    A computer virus, much like a flu virus, is designed to spread from host to host and can replicate itself. In more technical terms, a computer virus is a type of malicious code or program written to alter the way a computer operates and is designed to spread from one computer to another. A virus operates by inserting or attaching itself to a legitimate program or document that supports macros in order to execute its code. In the process, a virus has the potential to cause unexpected or damaging effects, such as harming the system software by corrupting or destroying data (Norton.com, n.d.).

    How does a computer virus attack?

    Once a virus has successfully attached to a program, file, or document, the virus will lie dormant until circumstances cause the computer or device to execute its code. For a virus to infect your computer, you must run the infected program, which in turn causes the virus code to be executed. This means that a virus can remain dormant on your computer, without showing major signs or symptoms. However, once the virus infects your computer, the virus can infect other computers on the same network. Stealing passwords or data, logging keystrokes, corrupting files, spamming your email contacts, and even taking over your machine are just some of the devastating and irritating things a virus can do. While some viruses can be playful in intent and effect, others can have profound and damaging effects. This includes erasing data or causing permanent damage to your hard disk. Worse yet, some viruses are designed with financial gains in mind. (Norton.com, n.d.)

    How do computer viruses spread?

    In a constantly connected world, you can contract a computer virus in many ways, some more obvious than others. Viruses can be spread through email and text message attachments, Internet file downloads, and social media scam links. Your mobile devices and smartphones can become infected with mobile viruses through shady App downloads. Viruses can hide disguised as attachments of socially shareable content such as funny images, greeting cards, or audio and video files. To avoid contact with a virus, it’s important to exercise caution when surfing the web, downloading files, and opening links or attachments. To help stay safe, never download text or email attachments that you’re not expecting, or files from websites you don’t trust. (Norton.com, n.d.)

    What are the signs of a computer virus?

    A computer virus attack can produce a variety of symptoms. Here are some of them: (Norton.com, n.d.)

    • Frequent pop-up windows. Pop-ups might encourage you to visit unusual sites. Or they might prod you to download antivirus or other software programs.
    • Changes to your homepage. Your usual homepage may change to another website, for instance. Plus, you may be unable to reset it.
    • Mass emails being sent from your email account. A criminal may take control of your account or send emails in your name from another infected computer.
    • Frequent crashes. A virus can inflict major damage on your hard drive. This may cause your device to freeze or crash. It may also prevent your device from coming back on.
    • Unusually slow computer performance. A sudden change in processing speed could signal that your computer has a virus.
    • Unknown programs that startup when you turn on your computer. You may become aware of the unfamiliar program when you start your computer. Or you might notice it by checking your computer’s list of active applications.
    • Unusual activities like password changes. This could prevent you from logging into your computer.
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