Data released this week from Google offers insight into the prevalence and growing threat of rogue, or fake, security software.

According to Google’s new report, based on a 13-month study of fake anti-virus distribution:

• Between January 2009 and February 2010, fake anti-virus made up 15 percent of all malware that Google detected on websites.

• In an analysis of 240 million Web pages collected by Google’s malware detection infrastructure, more than 11,000 domains were found to be pushing fake anti-virus software on website visitors.

• Fake anti-virus ploys are responsible for 50 percent of all malware delivered through advertisements – a five-fold increase in a single year.

Learn more in the IDG News Service coverage or take a look at the full Google report (PDF).