877-593-7906: this number has apparently been active for some time.
So this is the number for Microsoft and Fidelity – I was not able to reach anyone when I called.
Also according to Google Search it used to be the number advertised here:
https://livesupport247jp.com/ – the number is currently 866-895-1868
The website is registered in Vietnam.
This site has been reported here before:
And some guy who writes a bunch of long-winded “disclaimers” says it was a PayPal number:
I called 866-895-1868 and it was busy for me.