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Email, Security

Viruses, Trojans, Spyware – what do they all mean?

Most of us understand there are dangers to be met through surfing the web and sending or receiving emails. We’ve probably all heard the terms ‘trojan’, ‘spyware’ or ‘virus’ but what are they, how are they different and what do we need to be aware of?

There are several types of malicious software (or ‘malware‘) that can affect your computer and it’s important to know what to look out for and how to protect your computer.

The main types of malware are:

  • Viruses;
  • Spyware;
  • Adware;
  • Trojans (‘trojan horses’);
  • Scareware;
  • Worms.
Malware logo Crystal 128.

Malware logo Crystal 128. (Photo credit: Wikipedia)

Viruses are small piece of malicious software that can install themselves on your computer and cause a lot of harm to files, other programs and in worst cases, the entire kernel or master boot record of your computer. They usually propagate themselves between computers and can rely on people not being aware of suspicious items.

Spyware is harmful because it can see what you are looking at on your computer, browsing habits and can detect keystrokes or even with the intention of stealing passwords, bank details or other confidential information. Sometimes spyware can be used for consumer technology by detecting where you buy things from – did you visit one website and find something for a cheaper price than another? Other times it can be used for much more malicious reasons such as to detect and hack into your online banking system or steal your details for identity fraud.

Adware is usually harmless from a data security and computer-health perspective but adware is usually installed when you inadvertently check or uncheck a box on a web form that permits a website to install something on your computer. These types of malware are usually paid per install and so clever tricks are often used to disguise the fact you opt to install them. The Ask toolbar or other pop-up software will probably slow your computer down a great deal and also aggravate you when you are trying to use your computer.

Trojans are really bad news (although make no mistake – no malware should be taken lightly). Trojans are types of malicious software that promote themselves as something harmless and are manually installed by a naive user who thinks the scam email/website they are looking at is not risky. They can be used to remotely control a computer to cause all sorts of damage and can be used to perform large-scale DoS attacks (denial of service) which may affect your computer or hundreds of others.

Scareware is a something that pops up on your computer, when you are connected to the internet to tell you an apparent warning about your machine – sometimes it will tell you that you have a serious virus, that your firewall is causing problems or similar efforts to catch your eye. The tricks used deceive the user into buying their expensive service in order to return to a safe web browsing environment.

Worms are examples of self replicating malware that can infect computer-to-computer through security loopholes such as your firewall ports being misconfigured. These are particularly harmful in a network environment when 10s, 100s or 1000s of computers could be affected.

All types of malware will drastically reduce the speed and general health of your computer.

There are lots of things you can do to make sure you are protected and also to ensure you are internet-savvy with respect to noticing potential dangers. Some things that should set some mental alarm bells after your machine gets infected, include:

  • Slow computer performance;
  • Moving mouse cursor without moving the actual mouse or track pad;
  • Blank screen;
  • Computer restarting;
  • Peripherals not working (mouse, keyboard etc.);
  • Programs crashing.

What can you do to protect your computer?

  • Purchase internet securityNorton, McAfee, Sophos, Symantec, Microsoft Forefront and Trend Micro – these are all good brand names. Be sure to purchase the internet security and not simply ‘anti-virus’ because by the above definitions, you will need to cover everything. You get what you pay for with internet security and don’t be tempted to cut corners;
  • Look out for potentially suspicious emails – if you are not expecting an email from Paypal, a ticketing system or a friend whose name you’ve never heard off then don’t be tempted to click any link or open any attachment. These emails are usually non-specific such as ‘Nice to see you friend’ or ‘Your lost Paypal details.’ As a rule of thumb, banks and similar authorities will never send you account related emails unless you have made a transaction;
  • Be aware for scareware pop upsthese can look exactly like genuine pop ups on your computer but there is a trick: When you hover over a genuine computer warning, your mouse cursor will remain as an arrow. If you are seeing a malicious pop up, it will most likely turn to a little hand, or the symbol you get when you hover over a hyperlink (internet link);
  • Always check the integrity of website you visit. Websites with lots of pop ups are likely to be dangerous and those offering almost unbelievable deals such as ‘free iPad click here’ or ‘1/2 price shopping for life’ will almost certainly be scams;
  • Check the integrity of suspicious emails. Large corporations such as Paypal, banks or DVLA will actually have a ‘suspicious email checker’ on their website where you can find out how to check if your email is legitimate;

Above all, use the golden rule that ‘if you’re not sure – ask someone who can help.’ This may be a person in your family, at work or a computer assistance service.


About theithandbook

Reaching every day people and businesses with simple, effective and modern IT advice.



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