Nearly one in five US adult surfers has been a victim of at least one internet scam, according a recent survey commissioned by Microsoft.

Some 81 per cent of these victims admitted that they did something to compromise their own security, such as opening an email message that appeared to be from a legitimate person or company.

Security experts at Microsoft said that the biggest threats facing consumers online this year are criminals posing as trusted third parties to extract personal information.

"Microsoft has witnessed a shift in criminal behaviour in the past year," said Adrienne Hall, senior director of communications and marketing at Microsoft.

"The internet has changed the way we live, but many of the experiences that make the internet so valuable in our daily lives also require us to share information about ourselves that can present certain risks."

Despite increasing media exposure and user education about identity theft and online fraud, many people are still not getting the message.

"Most surprising was the fact that more than half of those surveyed admitted that they had little or no knowledge of current online threats and scams. Unfortunately, this is why people continue to fall victim to these crimes," added Hall.

The survey also found that men claim to be more informed about online fraud. Around 47 per cent of men indicated that they are 'knowledgeable' or 'very knowledgeable' about online scams, compared with only 36 per cent of women.

However, it seems that men are more likely than women to be victims of online crime. Some 69 per cent of women claimed that they had never been a victim of an internet scam, compared with 63 per cent of men.

Hall explained that, although strong and simple-to-use security tools are important, user education is paramount in helping to prevent online fraudsters from successfully launching these scams.

"As our survey illustrated, people need to be constantly updated to the threats that exist and how to avoid them," she said.

"Security threats are an industry-wide issue, and it is important that the industry works together to stay ahead of criminals and help inform and protect customers."