Despite an increase in online crime, nearly half of all internet users don't pay due care and attention to their PC security, Get Safe Online has warned.

The Government-backed campaign said its latest research showed that although more than eight in 10 people are using some form of anti-virus protection, nearly half fail to regularly update it, leaving them vulnerable to new attacks.

In addition, almost a quarter (23 per cent) do not have any anti-spyware protection, and nearly half (47 per cent) do not have website authentication software to protect themselves from phishing attacks.

At the start of the fourth annual Get Safe Online Week, experts at the organisation warned that working adults on an average salary can be worth £14,500 per fraud attempt to online criminals.

Information such as names, addresses, date of birth and sensitive financial details such as bank account and credit card numbers are harvested to carry out various crimes. Data can be used to drain bank accounts and sold on to other criminals; it costs as little as £5 for an individual piece of data and bundles of data, which are enough to steal someone’s identity, change hands on criminal message boards for around £80.

Tony Neate, managing director of Get Safe Online, said: "We are actively encouraging more people to go online but in doing so, to ensure that they are safe and secure.

"We want to draw attention to the fact that online criminal activity can be a sophisticated business, but that each of us can take steps to prevent ourselves from becoming a victim.”

“If internet users invest a relatively small amount of time and money in ensuring they are fully protected and up to date, the risk of such financial loss is almost negligible.”

The aim of Get Safe Online Week is to give everyone the tools and confidence they need to enjoy and use the internet safely.

The campaign points out that internet fraudsters take as much advantage of an individual’s accessible finances as they can in a short space of time, before moving on to the next victim. For most people, this could mean emptying their current and savings accounts, and spending the full limit of their credit cards.

Notably, despite the rise in the number of phishing attacks – it is alarming the number of people (47 per cent) the survey found who do not use some form of website authentication software or who click on emails.

This year 23 per cent of UK internet users surveyed said that they or someone they knew had fallen victim to a phishing attack this year, compared to just eight per cent in 2007. The fact that the survey found nearly one in five people use only one password for all websites that they use makes it even easier for these fraudsters to hack into other accounts.

Home Office minister Alan Campbell said: “It is important that we stay one step ahead of criminals who increasingly use sophisticated computer networks and the internet to commit and facilitate crime. That is why we recently announced a new £7m police unit dedicated to tackling cybercrime and clamping down on internet fraud.”

Information and advice on how to guard against online identity fraud and other internet crime can be found at the Get Safe Online website.