This test has been retired in favor of the badssl.com Dashboard.
You can still find Superfish removal instructions here.
What's this about? Turns out Lenovo preloaded their laptops with adware that will intercept all your secure connections, and allow criminals to do it, too.
After investigating the Lenovo incident we found out that many other softwares - like some Parental Controls or security packages - do things even worse for your security. This test attempts to detect them all.
Thanks to Karl Koscher, Paul Pearce, Marc Rogers, @TheWack0lian and all the others that discovered and divulged this.