Google today patched 20 vulnerabilities in the desktop edition of Chrome and added new anti-malware download warnings to version 17.
The company called out a pair of new features in Chrome 17, including the expansion of anti-malware download warnings and prerendering of pages suggested by the address/search bar's auto-complete function.
Google last refreshed Chrome eight weeks ago, on Dec. 13. Google generates an update to its "stable" channel about every six to eight weeks, a slightly more flexible schedule than rival Mozilla's every-six-weeks pace.
One of the 20 vulnerabilities patched today was rated "critical," the most dire ranking in Google's threat system. Eight were marked "high," while five were labeled "medium" and six were tagged "low."
Google paid $10,500 in bounties to four researchers for reporting 11 bugs, and another $3,133 to one of the four who uncovered a serious flaw that was quashed by developers before Chrome 17 made it to today's release. The nine other vulnerabilities were uncovered by members of Google's own security team, which includes developers who contribute to the open-source Chromium project -- which feeds code to Chrome -- or those who, for one reason or other, were not bonus-eligible.
Per its usual practice, Google blocked access to its bug tracking database for all 20 vulnerabilities to prevent outsiders from obtaining details that could be used to build exploits. Google typically opens up the database weeks or even months later, after it's sure a majority of users have migrated to the new edition.
Google typically includes a handful of obvious changes in each Chrome upgrade, and it stayed with that practice today: The two features visible to users were an extension of Chrome's long-running anti-malware download warnings and faster displaying of some Web pages.
The new download warnings alert users when they try to retrieve executable Windows files -- including those with the ".exe" and ".msi" extensions -- that Google knows or suspects are malicious, or are hosted on a website that commonly distributes threats.
Such warnings have been part of Chrome since version 12, which launched in June 2011, but they've been expanded in Chrome 17.
If the file isn't a known quantity or isn't from a reputable publisher, information about the file is sent to Google, which runs it through an analyzer to rank its "reputation and trustworthiness [compared to] files previously seen from the same publisher and website," said the company last month.
Suspicious files -- ones that match the criteria of others known to come from the same source -- are tagged, and if there's a high probability that it's malicious, the user sees an alert.
Google has also beefed up its anti-phishing tool; Chrome now inspects the destination URL for characteristics common to sites that try to steal confidential information, and if it makes a match, it spits out a warning.
The new anti-malware tools have been available in the beta of Chrome 17 for a month.
Also new to Chrome 17: Preloading of pages that appear in the browser's combination address/search bar when users start typing an address or search string.
"If the URL auto-completes to a site you're very likely to visit, Chrome will begin to prerender the page [to reduce] the time between when you hit Enter and when you see your fully-loaded Web page," Google explained last month when it added the feature to Chrome 17's beta.
In admittedly unscientific tests of Chrome 17's preloading, however, Computerworld did not notice any difference in the speed with which pages popped up.
According to metrics company Net Applications, Chrome accounted for nearly 19% of all browsers used in January, keeping it in second place behind Firefox (with 20.9%) and Microsoft's Internet Explorer (53%).
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed . His email address is firstname.lastname@example.org.