Microsoft and Hewlett-Packard on Tuesday unveiled free tools to help Web developers and site administrators defend against the rapidly growing number of SQL injection attacks that aim to hijack legitimate sites.

"We released two new tools, and HP has released one, to help administrators discover flaws so that they can mitigate attacks," said Mark Miller, director of Microsoft's Trustworthy Computing product management.

The move is in response to a major upswing during the first six months of 2008 in the number of attacks targeting legitimate sites. Most of the hacks have used SQL injection attacks, and have compromised significant sites including ones operated by government agencies, the United Nations and major corporations.

In a report issued the same day, Finnish security company F-Secure estimated the number of pages hacked by SQL injection attacks so far this year at between two and three million.

Previously, Microsoft has denied that its software was vulnerable to attack or otherwise responsible for the flood of hacked sites. Instead, the company told developers and administrators to follow the company's guidelines to protect their sites from attack.

That stance hasn't changed, but Miller said Microsoft's customers have been asking for more help. "We have seen a recent rise in the number of SQL injection attacks," he acknowledged, "and we wanted to provide some tools and guidance to users so that they could deal with these attacks."

One of the two Microsoft tools came from the company's IIS (Internet Information Services) Web server developers. Dubbed "UrlScan," it's actually an updated version of a tool last refreshed in 2003, said Wade Hilmo, a senior development lead in the IIS group.

UrlScan, Hilmo added, can now scan query strings -- not only a URL itself, as before -- so that it can filter the malicious strings that power SQL injection attacks. But it's only a temporary stopgap meant to protect a site while developers go into the code to correct the problems being exploited. "This is only a mitigation," Hilmo cautioned.

It should block the bulk of attacks, however. "UrlScan can filter out all the known versions of the attacks we've seen this year," said Hilmo.

Microsoft's SQL Server team contributed the second Microsoft utility, "SQL Source Code Analysis Tool," which analyzes ASP .Net code and sniffs out vulnerable bits. APS.Net is Microsoft's Web application framework, and a major target of 2008's injection attack campaigns.

Fixes, however, must still be made manually by developers, said Bala Neerumalla, a software security developer in the company's SQL group.

Users shouldn't think that Microsoft is getting altruistic, said John Pescatore, an analyst with Gartner. "Don't fool yourself, if these attacks were only against, say, MySQL, they wouldn't be doing this." Rather, Microsoft is reacting to the uptick in attacks against ASP.Net code, he continued.