My MacBook Pro is displaying a Microsoft virus alert.

The instructions that Old Toad posted will show you how to stop Web site notifications that are delivered via Safari, and that appear in the upper-right-hand corner of the screen. However, Web sites can also put up pop-up notices – and even try to lock the controls of your browser.

U.S. Federal Trade Commission – How To Spot, Avoid, and Report Tech Support Scams

"Tech support scammers may try to trick you with a pop-up window that appears on your computer screen. It might look like an error message from your operating system or antivirus software, and it might use logos from trusted companies or websites. The message in the window warns you about a security issue on your computer and tells you to call a phone number to get help.

…

If you get this kind of pop-up window on your computer, don’t call the number. Real security warnings and messages will never ask you to call a phone number."

Just to be sure I understand your post. When you open the Google Chrome app, you see a pop-up alert related to a Microsoft virus ... correct? This same alert does not appear when you do not use this app?

The other issue you mention is that the cursor does not work. Does not work where? Only in Chrome, or at all? Are you using the Mac's touchpad, or an external mouse/trackpad to control the screen's cursor?

In case it's adware popups from a website you visited try the following in Safari's Settings: