I have received calls twice in the last 3 weeks where the caller suggested my computer was at risk of being hacked and that I should allow him remote acces to my computer to fix the problem. The caller was persuasive, persistent and friendly, but I did decline the offer, suggesting one should never allow access to their computer to a caller. He called a second time and left a voice message claiming: "Security alert, security alert your Yahoo email has been used on other devices.Please call 1-888-991-3969."
Technical Support does not call you, you call them. And, never give a stranger who randomly contacts you remote access to your computer. Be careful and do not be fooled by the technical support scammers.