Mal/Iframe-F is a small or hidden iframe within a web page that attempts to run malicious software. It is often used by attackers as the first stage of a larger
web based malware attack.
At the time of writing Mal/Iframe-F is still one of the most commonly seen threats on web pages that have been compromised by malicious hackers. It is used to funnel web traffic from many compromised sites to one or two sites that are controlled by attackers and are hosting malicious software.