Security firm McAfee has released a new report warning of the ever-present threat of typo-squatting.

The report highlights the number of website squatters registering domains using common misspellings of popular brands, products and celebrities in order to redirect consumers to bogus websites.

These sites often use click-through advertising to generate revenues, and lure unsuspecting consumers into scams to harvest email addresses.

"Typo-squatting illustrates the Wild West mentality that remains dominant in major areas of the internet," said Jeff Green, senior vice president at McAfee Avert Labs.

"Even at its most benign, this practice takes consumers to places they never intended to go, and penalises legitimate businesses by siphoning off customers or making them pay a charge to reacquire customers.

"At its worst, typo-squatting leads to online scams, get-rich-quick offers and other risks."

McAfee reviewed 1.9 million variations of 2,771 of the most popular domain names, and found that a typical consumer who misspells a popular URL has a one in 14 chance of landing at a typo-squatter site.

Children's sites are heavily targeted; more than 60 of the most squatted sites are designed to appeal to the 18-and-under demographic.

Some typo-squatters also take advantage of typing errors to expose children to pornography. More than 46,000, or 2.4 per cent, of the typo-squatter sites tested included some adult content.

The practice is on the rise, the report found. Cyber-squatting cases filed with the World Intellectual Property Organisation's arbitration system increased by 20 per cent in 2005 and 25 per cent in 2006.

The emergence of new top-level domains, automatic registration tools, and the proliferation of parking portal sites that make it easy to generate pay-per-click revenue from squatted sites are all contributing to its growth.

On the up side, the report found that many search firms, such as Yahoo and Google, routinely offer alternatives for common misspellings, reducing the likelihood of landing at a typo-site by accident.

The report also provides information about companies and organisations joining in the battle against malicious typo-squatting.

Microsoft offers a range of tools that allow users to help identify and analyse typo-squatters.