iframe
HTML element to embed one site into another
An iframe is an HTML element that can be used to embed the contents of one website into
another. The embedded website can live on the same domain as the main site, or on an entirely
different one. Many legitime websites use iframes and they have become popular with the growth of
Ajax applications.
Iframes are also frequently used by malware authors to spread their
malicious programs. By including an iframe of tiny dimensions into a hacked website,
or one that the user is lured to visit using social engineering, they can allow
the browser to visit a malware-serving website without the user realising. See also
drive-by download.