At least one of every 20 executable files on the Internet contains hidden spyware, according to new research from University of Washington computer scientists.
UW researchers sampled more than 20 million Internet addresses covering games, news and celebrity-oriented Web sites. They found that one in 62 Internet sites performed a nasty little trick called a "drive-by download," forcing spyware onto people's computers whenever they visit the page.
The worst offenders? Game and celebrity Web sites had the most spyware, while sites offering pirated software tended to do the most drive-by attacks.
The researchers recommended using at least two anti-virus software programs and keeping them up to date.