|It has been over a year and a half since we started to identify web pages that infect vulnerable hosts via drive-by downloads, i.e. web pages that attempt to exploit their visitors by installing and running malware automatically. During that time we have investigated billions of URLs and found more than three million unique URLs on over 180,000 web sites automatically installing malware.
Niels Provos, Google Anti-Malware Team
In the past few months, more than 1% of all search results contained at least one result that we believe to point to malicious content and the trend seems to be increasing.
Ordinary web pages are contributors to web exploitation. Therefore, even if someone was to avoid adult web pages, she would still be exposed to risk.