Microsoft has blacklisted my site as a phishing site

When I browse to be Store controller from the internet the browser displays the following warning and makes using the site hard.

This warning is being reported and generated by the browser, not Fieldpine. To resolve the problem you will need to click the links and report the site is not an issue.

Why did this happen?

Asumming your website was not involved in a phishing attempt, which would be surprising as most resources are locked behind password protection, then we can only guess at possible causes

• Your site is/was truely involved in a phishing attempt
• Is your site a subdomain, such as mystore.example.com. Where other sites might be using someone-else.example.com. It is possible that Microsoft is blocking example.com and you are implied as the same site. While this might sound wrong, browsers rely on something called the public suffix list to determine where different ownerships might exist. The PSL might be telling the browser that mystore and someone-else are both the same owner.
• The reported site used the format brandname.example.com, where brandname.com was a well known site, and example.com (the real site is not example.com and has been redacted) has been implicated in typo squatting. The store owner in this case is a "brandname" reseller, but potentially automated tools cannot know this.
• Something else? There are many other possibilities, but only Microsoft knows the true reason.

Technical Notes

In the example reviewed, this warning appeared shortly after connect and before the login details could be entered

1. Browsed to http://...../report/pos/sshome.htm
2. Server returned "401 Unauth" to the browser
3. Meantime (asynch) the browser switched and displayed the above warning.