Google has enhanced the way it notifies webmasters that their sites contain malware, improving on a service the company launched last November in a partnership with The Stop Badware Coalition.

Google has begun providing more detailed alerts and to send these notifications via email to webmasters, according to a posting on an official Google blog.

Previously, Google only informed webmasters that their sites had been identified as having malware and made generic suggestions for fixing the problem. Now, the company also points webmasters to specific offending pages from their sites that Google has determined contain malicious components.

"This can be helpful when the malicious content is hard to find," the posting reads. "By providing example URLs, webmasters are one step closer to diagnosing the problem and ultimately re-securing their sites."

Before, Google notified webmasters by placing a note in the site's summary page in Google's Webmaster Tools site, but now it is sending the alert via email as well.

These two improvements will prove useful, according to Aaron Pratt, a webmaster who writes about search engine optimisation in various blogs, including Internet Marketing Guide and SEO Buzz Box.

However, he expects Google will continue perfecting the service. "I recently had my site compromised [by a malicious hacker] and it went undetected in Webmaster Tools," he said. Pratt also suggests that Google build on this tool, by giving it a more advanced interface so that it can alert webmasters about other site issues beyond malware that violate Google guidelines.

Google flags websites according to guidelines set by The Stop Badware Coalition. Webmasters who feel their sites have been incorrectly flagged as having malware need to contact the coalition and request a review.

In August, and also in conjunction with The Stop Badware Coalition, Google started displaying malware alerts for users of its search engine.

When users attempt to click over to a website considered to be potentially dangerous, Google shows an alert page that informs them of the possible risk and gives them the option to click back to the results page or continue on to the questionable website. However, these alerts sometimes anger webmasters who are convinced their sites don't contain malware.

The Stop Badware Coalition is a nonprofit organisation led by Harvard University and the University of Oxford and backed by Google, Lenovo and Sun Microsystems.