I am often asked why people bother making viruses or sending spam but the answer is all too depressingly simple – money.

The most obvious way to make money from a compromised computer is to scour it for information and sell the good bits for cash. Nice bits like credit card information, passwords to bank accounts and so on all have market worth and it is for this reason that if you try and buy compromised machines (and you can) then machines from first-world countries are worth more than third world –based devices.

This happens so often as to be hardly worth mentioning. Every week I will clean at least one machine just in the area surrounding Killarney that has a virus designed for that very purpose. It is so common that if someone asked me why they had unexplained transactions on their credit card or their credit rating had just plummeted into the abyss I would just tell them to check their computer.

However, extortion is another method of making money out of a compromised computer and this has been a problem in the West of Ireland too. Instances of Irish businesses, usually small ones, that have had their computers taken over and the data stored upon it being encrypted thus rendering it inaccessible have been on the rise. The businesses will then receive a request for money and in return they get the code that can be used to decrypt the data.

Prevention is, of course, far better than the cure but a normal daily backup would obviate the need to pay the ransom as you would simply restore the unencrypted versions of the data from backup. All that would be lost is some time while you recover the data from the backup media and clean the infected machines.

So it looks as if the Internet has now spawned its own version of Dick Turpin, the infamous Highwayman from Essex of the 1730s with the simple difference that the person doing the robbing doesn’t have to be around in person to take the spoils.