I was checking over my error logs recently, looking for problem pages that should be redirected, and found repeated attempts to load FormMail. Now, I do have a form-to-mail CGI on my web host, but not FormMail. FormMail is by far the most popular of these widgets. I was briefly puzzled by the request to load it: I’ve never had it installed, never had a link to it, so I couldn’t quite figure how it could be a bad link.
Until I read a comment on a story somewhere else mentioning that FormMail had a security flaw that made it available for hijacking by spammers. The flaw has been corrected, but it stands to reason there are lots of old installs of it floating around, ripe for the picking.
Unfortunately, formmail has been a never-ending cascade of security problems. It is so widely used and so badly flawed, there are indeed bots that scan the web looking for it.
A good alternative is the NMS (Not Matt’s Scripts) version, at http://nms-cgi.sourceforge.net/