What are the effects of computer viruses to the computer?

Answer 1

There are many effects of Computer Viruses to a computer, but it all depends on the type of virus. There are many types, including worms, malware, viruses, among others. A worm is simply a quine (self-replicating program) that does damage to your computer in a certain way. Malware is similar, but instead of self replicating, it is just the broad category of software intended to damage or disable computers and computer systems. Viruses are another broad category, comprised of programs still capable of reproducing themselves and usually capable of causing great harm to files or other programs on the same computer. A true virus, however, cannot spread to another computer without human assistance.

Each of these types of viruses can do damage in a myriad of ways, depending on the virus. Online, you can be attacked by phishing, or a fake website that attempts to get you to enter personal data. (ie a fake facebook login page to get your login, etc) If this happens, then the safety of your online data will be compromised, and the hacker/cracker/attacker will have access to your accounts. If you download a virus, or a Trojan for that matter (just a virus that looks like a legit program) onto your computer, it can do just about whatever it wants, depending on the strength of the virus. A weak virus will probably not do much more than slow down your computer, disable programs, or attempt to lock you out of your own data. Usually, however, anti virus software is easily able to nab these programs and nip them in the bud; well before any lasting damage is done. (Some good Anti-Virus software is Norton, Symantec, or Siemens)

A more powerful virus, however, can do a lot more damage. Many strong viruses will disable your anti-viral as soon as they hit your computer, and then place itself deep in your hard drive. Here, it can corrupt data, shut down ports, internet connection, regulate input and output from the computer, disable all executable programs, limit access to files and data, among others. Another scary component of viruses is the ability to avoid deletion. Strong viruses usually will know when the delete command has been executed on itself, and just before the command is completed, it will move itself, rename itself, and then send fake data to the computer, telling it that the virus had been deleted. When it moves, it doesn't just move around 'My Documents' either; it moves deep within the computer registry, hopping through files that you will probably never see.

Once I got a strong virus that shut down all outgoing ports except one, which it then controlled to download 2532 different viruses onto my computer, just to make the situation worse. It then disabled all executable programs (exe's, bat's, msi's, etc) and disabled access to my data. It corrupted all restore points, and every time I found it, it moved itself. I had to wipe my drive and reinstall!!

Good luck avoiding viruses in the future!!