I have closed out the other duplicate question you opened up for this issue; good to know that you were able to get rid of the rogue webpage for now by restarting the system. Yes, your browser was hijacked by a malicious party that was showing up this fake alert/popup, and has nothing to do with Microsoft at all. However, to make sure that your Chrome browser is completely clean now, please do this as well:
Click on the icon with three dots at the top-right of the browser window, and then click Settings.
Scroll down to the very bottom and click "Show advanced settings".
Next, scroll down further to the bottom and click "Reset settings", and reset Chrome when prompted.
This should do it. If you need more help, please use the Reply box below to continue our conversation.
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