While using IE 11.0, the following message popped up: "Your IP 173.27.14.254 has been blocked! A serious malfunction has been detected with Windows 10 and your IE 11.0 ... DO NOT SHUT DOWN OR RESTART YOUR COMUTER .. CALL 855-307-5195".  When I called, a person at "iSupport" told me that my computer was suffering a massive virus attack, that Webroot Secure could not stop it, but their technician could for $180.  Is this legitimate?