As Microsoft unveiled details of a "more secure" desktop operating system this week, news emerged that the company's browser is losing business users because of - among other things - security.

A survey of 168,000 surfers hitting business web sites has found Internet Explorer has lost nearly two percentage points of market share. IE's open source nemesis Firefox, meanwhile, doubled its presence.

Janco Associates found IE had 83.7 per cent of the market for this month, down from 84.85 per cent, while Firefox grew from 4.23 per cent to 10.28 per cent. Janco believes Firefox could take 25 per cent market share in the next quarter.

Separately, Infocraft reported the browser is approaching nearly 50m downloads, up from February's milestone figure of 25m, which was recorded 99 days after Firefox 1.0 became available last November.

Janco's chief executive, Victor Janulaitis, said, "There's a lot of people who say: 'I'm tired of Microsoft. The one thing that has gotten us, is Microsoft knows about security defects, but it takes a long time to get it fixed'."

According to vulnerability monitoring service Secunia, 19 out of an estimated 80 security advisories for IE 6.x currently remain "unpatched" compared to four from a total of 15 Firefox 1.x advisories. Secunia says warnings for IE range into the category "highly critical" while outstanding Firefox alerts are "less critical".

Janulaitis cautioned that Firefox's reputation for security would likely be eroded as the browser becomes more widely used and hackers increase their attacks. ®

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