A study commissioned by Mozilla claims that the anti-phishing filter in Firefox 2.0 beats Microsoft's Internet Explorer 7 hands down.  

The study found that Firefox in its most secure configuration blocked 81.5 per cent of all phishing websites. Internet Explorer 7 blocked just 66.35 per cent of the phishing sites, according to the Mozilla study.

Firefox 2.0 failed to flag a phishing site in 117 instances when Internet Explorer 7 did catch it, while the Microsoft browser let 243 URLs slip through that Firefox stopped.

Paid for by Mozilla, the study was performed by SmartWare, a technology, strategy and marketing firm. The test methodology and results were audited by security testing provider iSEC Partners. 

The test fed a series of known phishing URLs from PhishTank to the browsers over a period of two weeks in late October and early November.

A similar study carried out in September by Microsoft gave top marks to Internet Explorer 7. The study did not test Firefox 2.0 but compared the browser to seven third-party security applications. 

The Microsoft study was performed by 3Sharp, a company specialising in messaging architectures that has no track record in market research and security analysis.

Mozilla's study results are available on the Mozilla Developer Center website.