Viruses
What is a virus?
A computer virus is a file that infects a PC and changes its settings, often damaging or stopping it from working altogether. Many viruses are malicious and are designed to steal or destroy people’s private information.

Viruses often come in emails masquerading as something of interest. They try to trick you into downloading attached files, infecting your PC in the process.

It is much rarer but viruses can also come through websites or downloads from the internet. You do not have to have visited dangerous sites to be a victim; genuine sites can sometimes carry viruses without realising it.

How do I avoid them?
The most important thing you need for a computer is anti-virus software. There are a number of free versions available. Microsoft has an anti-virus package called Windows Defender and a company called AVG also offers a free version of its software.

However, these are all cures and not preventions – the best way to avoid getting a virus is to be vigilant against suspicious sites and emails. Do not download a file – particularly if it ends in .exe – from a website you do not trust and do not open the attachments on emails from people you do not know. Real email accounts can be hijacked too so, if you get a suspicious email from a friend, it might be best to check with them before you open it.

Spyware and adware
What is spyware/adware?
Spyware is much like a virus but is designed to be covert. It sits quietly in the background of your computer, logging your private information and sending it back to its creator. This might be log-in information for a website or even your date of birth, credit card number or address.

Adware, on the other hand, spams your machine with advertisements in the form of pop-ups and fake warnings – for example, one threat cheekily warns you that your computer has a virus and sends you to a page where you can buy the software to remove it.

Spyware and adware can get onto a computer just like a virus – through infected files – and can even be attached to seemingly innocent software.

How do I avoid spyware and adware?
Again, vigilance is key but, as spyware and adware are much trickier, they can get on to the computer of even the most careful surfer.

The best defence is to have a firewall, which monitors the programs that are connecting to the internet and what kind of information is being sent or received. This will stop software from connecting to the internet unless you tell it otherwise, which means that any spyware and adware on your PC will not be able to send out sensitive information.

Microsoft has a free firewall that is built into most versions of Windows XP and all versions of Vista and Windows 7. Go to your control panel and view your security settings to see if it is activated. Other free firewalls are also available, with one of the most popular being ZoneAlarm.

These packages should neutralise the threat but, to be extra safe, you should also install and run Spybot: Search & Destroy and AdAware. These free downloads will scan your PC to see if any spyware or adware is on your machine. If it finds them – and it probably will – it will wipe them away.

Phishing
What is phishing?
Phishing is when a scammer tries to trick you into sharing personal information, such as bank account details. It is usually done by email and can come in the form of a fake message from your bank, a request for help from a ‘rich’ individual or a claim that you have won the lottery.

As they are sending out thousands of emails, they only need one to work to make it worthwhile; much like a fisher only needs one fish in thousands to make casting a line worth doing.

How do I avoid phishing scams?
The common-sense rule of ‘if it’s too good to be true, it probably is’ applies. Once a little bit of logic is applied, the scams will become obvious. For example, it is very hard to win a lottery for which you have not bought a ticket!

Some are cleverer, though, such as those claiming to be from your bank. These official-looking emails link you to what appears to be your internet banking log-in page. However, in reality it is a duplicate site that the scammers control. They hope you will enter your log-in details so they can then use them on the bank’s real site to take your money.

Irish banks never send out emails like this so you can instantly ignore any such mails you receive. If you are not sure and want to double check, be sure to visit the bank’s website by typing in the address yourself rather than by following the link in the email.