Trojans & Worms: How to Guard Yourself Against Digital Pests

July 23rd, 2014

Laptop and Computer Virus

A computer virus is a malware program that, once installed, replicates itself and spreads to other programs or files or to a computer’s hard drive. It is code that is usually created to harm a system in some way, such as by stealing disk space, corrupting or destroying data or logging keystrokes to steal information without the user’s knowledge.

Types of viruses

There are many different kinds of computer viruses with a startling variety of names and numbers, but most viruses fall into three basic categories. These are:

  • Trojan Horses – these often innocent-looking files, once downloaded, expose your computer to malicious intruders, allowing them to access your files remotely.
  • Worms – these viruses copy and multiply themselves and are capable of spreading through entire networks via loopholes and weaknesses in the system. A classic example is the ILOVEYOU virus, which attacked tens of millions of computers worldwide in May 2000.
  • Email Viruses – these viruses use email to spread themselves and can automatically forward themselves to thousands of different recipients. They rely on the user opening an attachment, which then releases the virus into the computer.

How you get them

Just as there are many different viruses out there, there are many different ways of contracting them as well. These include:

  • Clicking on unknown prompts or messages – ironically, virus warning popups can often be hiding viruses. Free software offers can also contain viruses, which are downloaded along with the software.
  • Visiting infected websites – visiting websites that are unknown to the user always carries with it the risk of picking up a virus on your web browser.
  • Opening email attachments from unknown sources – attachments from unknown senders often contain viruses and sometimes from known sources as well, where the sender has been infected and then passes the infection on unwittingly.
  • Downloading infected software – any software has the potential to contain a virus and software such as pirated music, movies and games carries a greater risk than most.
  • Not keeping software updated – software manufacturers release periodic updates (firmware) which usually contain improved security and virus protection, so failing to update when they become available exposes you to a greater risk of infection.

How to cure them

If you do contract a virus, you will probably experience one or more of the following symptoms:

  • Sluggish operation
  • Altered appearance of your web browser
  • Being redirected automatically to an unknown site
  • Computer crashing for no reason
  • Messages warning of corrupted files.

Curing a computer virus is not normally something the layman would know how to do. There are however, certain basic steps you can take that may help.

First and foremost, try using anti-virus software to locate and remove the virus. This may or may not work, depending on whether the virus has coding that disables anti-virus software (some do).

If you can’t access your anti-virus software, try downloading anti-virus software from another computer and loading it onto your computer via a disk or flash drive. If you are running Windows 7, you can run the Microsoft Safety Scanner from their web page, or if you can’t access the internet, it can be activated by accessing the Advanced Boot Options on your computer at startup (press F8 repeatedly).

If all else fails, you can try formatting the hard drive, which will mean you will lose all of your data, or take the computer to a repair shop to see if they can fix the problem for you.

How to prevent them in the future

Prevention is always better than cure and there are plenty of simple precautions you can take to limit the likelihood of contracting a virus in the first place. These include:

  • Install reputable anti-virus software such as Norton or McAfee and ensure that it is set to regularly monitor your computer and download new virus updates automatically.
  • Do not open email attachments from unknown sources and if possible, scan those from known sources before opening, especially if you’re not expecting them.
  • Keep your firmware updated as well as your anti-virus software, to take advantage of every new security measure that is developed by the manufacturers.
  • Use a firewall, as this will not only alert you of any suspicious attempts to connect to your computer, but will also block intrusion attempts as well.
  • Use a popup blocker with your web browser, as pop ups can contain malicious viruses which are activated when you click on them. Blocking all popups will remove the temptation to do so.
  • If you are in business, train your staff to be aware of malicious emails, restrict web browsing to authorised users and specific sites, partition critical business information and restrict access to it and discourage the use of BYOD devices, unless they are regularly screened and updated.

New viruses are being created every day, so constant vigilance is the key to remaining infection-free. Eventually though, there may come a day when, despite all your best efforts, a piece of malicious code gets past your defences and cripples your system.

If this does happen, you will be thanking your lucky stars that you have backed up your data regularly and stored the backup in a secure place. At the end of the day, you can always get another computer, but you can’t replace the information that’s on it. If your business is experiencing issues or you suspect that your IT assets may be compromised, speak with Connected Intelligence IT security experts for advice.

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