Tweet from Microsoft Security Intelligence, https://twitter.com/MsftSecIntel/status/1161426701756141568
Quote
The 404 Not Found page tells you that you’ve hit a broken or dead link – except when it doesn’t. Phishers are using malicious custom 404 pages to serve phishing sites. A phishing campaign targeting Microsoft uses such technique, giving phishers virtually unlimited phishing URLs.
And here is a detailed explanation on how this cyber criminals are working very hard to trick everyone here, so just be careful.
https://nakedsecurity.sophos.com/2019/08/20/serious-security-phishing-in-the-cloud-the-freemium-way/