blackmail received by email

They are harassing me and asking for money.

Hello! _x000D_ This is important info for you!_x000D_ _x000D_ Some months ago I hacked your OS and got full access to your profile_x000D_ _x000D_ On day of hack your acc has pass: xxxxx_x000D_ _x000D_ So, you can change the pass, yes.. Or already changed... But my malware_x000D_ intercepts it every time._x000D_ _x000D_ How I made it:_x000D_ In the software of the router, through which you went online, was a vulnerability. I_x000D_ used it..._x000D_ If you interested you can read about it: CVE-2019-1669 - a vulnerability in the_x000D_ web-based management interface of the Cisco routers._x000D_ I just hacked this router and placed my trojan on it._x000D_ When you went online, my soft was installed on the OS of your computer._x000D_ _x000D_ After that, I made a full backup of your device (I have all your address book, history_x000D_ of viewing sites, all files, phone numbers and addresses of all your contacts)._x000D_ _x000D_ A month ago, I wanted to lock your PC and ask for a not big amount of btc to_x000D_ unlock._x000D_ But I looked at the web-history that you regularly visit, and I was shocked by what I saw!!! ...