Microsoft's Internet Explorer continues to dominate corporate browser use more so than it does private use, with its nearest rival, Mozilla's Firefox, lagging far behind with one in seven businesses opting for it, according to data collected by Internet-based security service Zscaler.

Businesses are also more careless about upgrading IE than the general public with 27% still using IE6, which has known vulnerabilities, says Zscaler, including the one that led to the notorious Aurora attack against Google and other U.S. corporations in January.