The tool takes advantage of cross-site scripting, a commonbug in Web sites that takes control of a user's browser when he or she clicks on a specially crafted link, or in some cases, simply visits a compromised page.
Britain's National Health Service says that the two most common causes of gastroenteritis in adults are food poisoning and the norovirus, a common winter vomiting bug which typically afflicts between 600, 000 and 1 million Britons each year.
Though the current bug has been patched, Oberheide says Web bugs like the one he found are too common for Google to allow installation of phone apps from the Web without warning.