I Googled the words,

"You need to clean your computer to prevent the system crash"

and I got a number of hits. From one of those websites, I gathered that the first might attempt to install a Trojan called "Windows ProSecurity Scanner." I Googled that term also and found a lot of hits re how to remove it if infected.

That's just FYI, to illustrate that this matter has been around awhile before it ever hit FT. I'd be afraid of the websites that offer to remove the alleged Trojan as well as the alleged Trojan threat. But my point is that there is some information out there evidently.